Making a Panther Platform Vehicle Handle ... Crown
Victoria, Grand Marquis, and Town Car
The
following article is aimed at making a Panther Platform vehicle handle better.
Who is X Racer (Author)?
X
Racer has raced, wrecked, broken parts & bones till he is now "X"
Racer. X Racer may not be the one to
listen too on much more than how to break something or wreck it. But since you are, X Racer is me. My father even took my first wheelchair away
from me because he thought I would kill myself in it. It could have been the ramp to ramp jumps or it could have been
doing wheelies down the road at 25 mph.
I did not mind as I had worn the tires off it in about 2 months. Wheelchairs were never engineered to carry
that much plaster of paris. Anyway,
the devil lured me into wanting to go fast.
So I raced MotorCross, Hairscrambles, Enduros, Trials, AutoX and some
flying competition. We want even talk
about the fast women. If I was not
racing, I was playing Football, Wrestling or Boxing. I have been kicked out of every Go-Kart track in Panama
City. I have also been kicked out of
half the Water Parks I go to for going to fast. Along the way I learned a bit about racing and Orthopedic
Doctors. Between all these mechanical
toys, I learned how to repair them, weld them, modify them, and then break them
again. Now that I am older, more
mature, and laid back, I bought a 92 Crown Victoria and now my current 99 Grand
Marquis. These cars should carry me
well threw my slower years. During my
first AutoX race in the Grand Marquis, I blew away 1/3 the participants in a
nearly stock, full treaded tir,e land yacht after waiting nearly 15 years since
the last AutoX. Don't even ask me what
happened at the last Auto X. You are
supposed to do better each time.
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Handling and what is it. So
you want to make your Crown Victoria, Grand Marquis, or even Town Car handle
better. Good, it is not that
hard. But first what is handling? Smooth ride, quiet ride, high cornering
limits, good steering response, confidence inspiring, stop watch says its
fast, 0-60, 60-0, 1/4 mile times, low vibration, traction, and many other
words describe |
|
Hi! My name is Sarah. I am here to help X Racer
show you how to handle the curves and bumps.
Along the way, I hope to teach him how to spell and use proper
punctuation. |
handling. Racecar handling and a smooth quiet ride
tend to conflict. We are lucky with
modern cars because they give both better than ever. If you go to modifying your car, you are shifting the compromise
that the engineers picked. Engineers
are not wrong or right with the settings they chose. There is nothing wrong with shifting the compromise to satisfy
your taste. Just remember, you rarely
get something for nothing. I will try
to let you know the pros and cons of each modification. It is a lot like an old radio with a
treble/bass knob. No one can walk up,
set it and say, "This is the only correct position". It is personal. We are talking about a handling Vs ride. Sometimes you can get a lot of handling with
little trade off in ride. Some
modifications give very little handling and kill the ride. Many of the modifications listed do very
little to the ride by themselves, but start adding them all together and you
may be making big changes. Many of us
bought our CV/GMs for the smooth quiet ride.
Many for the safety, spacious interior, 6 seats, and more. Only you can decide how much handling Vs
ride you want. My wife says her car is
stock and it will stay that way. She
says I ruined my cars ride. I love my
car's modifications and most of us on Crownvic.net/.org do. I promise to do one thing here and that is
give you the Pros and the Cons so you can make an informed decision.
Tires:
The
tires are your only connection between the road and your vehicle. No one part of your car can influence
handling more than tires. First lets
put a hole in the old fiction tale that wide tires put more rubber on the
road. When you put 34 pounds of air in
a tire, you do not pull out a scale and weigh 34 pounds of air to pour into
your tire. It means 34 pounds per
square inch of pressure. No more and no
less. The front and rear of our CV/GMs
weigh about 2200lbs and 1800lbs respectfully.
That would be 1100lbs for each front tire and 900 lbs for each rear
tire. 1100lbs divided by 34psi would be
about 32 square inches. If your 225
width tire were about 8.7" wide, the contact patch would be about 3.7
inches long. 3.7" x 8.7" x
34psi = 1094lbs. Close for rounding
off. A wider tire, say 10", would
have a contact patch 3.4" long.
Obviously you would have to reduce the square inches of rubber in
contact with the road because of tread groves.
All this math means one thing and that is, wide tires only change the
contact patch shape. And yes, this does
affect handling.
There
are only three ways to increase rubber on the road. Lower your air pressure, increase the vehicle's weight, and go to
racing slicks so there is no tread cut out.
Tires have an ideal air pressure for peak performance. Lowering the tire pressure will only hurt
traction. Increasing the vehicle weight
is a BIG no no! That only leaves race slicks and that is illegal, dangerous,
and useless in the rain. You are now 0
for 0 on increasing the contact patch.
Well not really ... I left you an out with "ideal tire
pressure". We will come back to
this.
Many
of us have put wide tires on and noticed a big improvement. Was it the width, or was it the tire
compound, cord material and layout, and the profile?
Lets
go straight to the number one influence on tire traction since obviously it is
not tire width. Here it is...
"Tire Design". Tire companies
design their tires for a purpose. The
best dry weather paved road tires are classified as "Max Performance"
tires. Next are "Ultra
Performance" tires and last are "Performance" tires. Please reread all the conditions. That was dry weather & paved roads. Not rain, snow, or off road. "Max Performance" tires have
nicknames such as gumballs, Auto-X tires, DOT race tires, and such. They are purpose built for racing. They ride rough, they are noisy, expensive,
dangerous in the rain, and have very very short life spans. A highway tire typically is rated around 600
to 700 on wear. These tires typically
run around 50! That is 1/12th to 1/14th
the time! Like I said they are for
racing only or for the rich on sunny days.
They also need a special break in to work their best.
Ultra Performance Tires:
Now,
that 99.9% of us were just talked out of "Max Performance" tires,
lets go to the next category.
"Ultra Performance" tires are full treaded and normally
perform very well in the rain. The tread
wear ratings run about 180 to 280. Not
great on wear but that is the price you have to pay for performance. Also some of them ride rough and are
noisy. www.tirerack.com
has excellent write ups and comparisons.
Spend some time at this great web site when it is tire time. High performance tires tend to handle
better, have better steering response, more neutral handling, more forgiving,
more confidence inspiring, better rain performance, brake better, accelerate
better, and flat out corner harder. You
buy a lot with your money here! This is
the first spot to not be skimpy with your money if you want good handling.
|
Plus
sizing has been proven to help handling while maintaining the stock gearing, ride
height, speedometer accuracy, and overall handling characteristics. The lower profile tires used in plus
sizing helps reduce slip angles, improves steering response, and they corner
harder on smooth roads. Using the stock wheels and low profile tires, will
lower the car, drop your gearing, improve steering, improve cornering power,
reduce wheel weight and rotating inertia, |
Rocket Couch ++sizing
|
and
throw the speedometer accuracy off. My
old 245x50x16 tires dropped the gearing the equivalent of going from the stock
rear end ratio of 3.55 to a 3.70. The
speedometer was off about 3 mph by the time I am running about 70 mph till
corrected with a performance chip.
When
it comes to ride, anything that firms up the tires will also hurt the
ride. That includes performance level,
plus sizing, profile, rim width, etc...
As
you firm up the sidewall with wide rims and/or the short sidewalls used in low
profile tires, the tires ability to grip on rough roads may be reduced instead
of improved. Our solid rear axles tend
to aggravate this problem. The vast
majority of pavement is not that rough.
Just be ready the first time you see ripples in the asphalt. That means slow down. Good shocks help offset this.
Next:
For
the next step in making your car handle, you need to decide what part of
handling is important to you. For most
of us, it would be confidence inspiring and fun cornering. Sway bars normally win with no contest. But the stock swaybars are not too bad on
the HHP cars and our stock shocks are soooo soft. Do shocks first if you have HHP bars and then swaybars or flip a
coin. It is close.
Shocks:
Bilstein
HD shocks are the only reasonably priced shocks that work on CV/GM cars. There are many shocks that do wonders for
other cars. They just don't work on
ours. The part numbers are:
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Bilstein
HD front P/N B46-1495 Bilstein
HD rear P/N B46-1496 They
run about $65 a piece. Better shocks
will help braking power and acceleration off the line on even smooth
roads. It will also help cornering
power and tire wear. Don't expect
night and day changes on these improvements.
Expect night and day on these:
no more float, confidence on rough roads is way up, much better
bottoming resistance, much tougher to
|
|
I
like a firm ride ! Let
me hold those big shocks while you tighten things down. |
belly
the car into the ground. Here is the
down side. Your passengers will not
sense the much improved handling that the driver will notice, but they will
notice the much firmer ride. The stiffer
ride opinions have varied widely amongst CV/GM owners. Bilstein shocks may not be consistent on
their dampening. This may be an area
where people vary a bit with seat of the pants judgement. Even though there is
no consensus on how Bilstein shocks affect the smooth stock ride, we all agree
it was worth the money. You definitely
get used to it. I have one advantage
over others and that is my wife also has a 99 Grand Marquis HHP. I can do back to back comparisons to a stock
GM. That way my slipping memory does
not get off base.
Here
are the specifications on dampening rates in lbs. for both standard Bilstein
shocks that are virtually the same as stock and HD Bilstein shocks:
B46-1497 Comfort, Front 1240 compression, 1040 rebound (Close to stock)
B46-1498 Comfort, Rear 1000 compression,
470 rebound (Close to stock)
B46-1495 HD, Front 3090 compression,
2000 rebound
B46-1496 HD, Rear 1750 compression, 850
rebound
So
you say you want Max Performance from your Bilstein shocks. Call up Energy Suspension and order
polyurethane shock mount bushings. This
will help tie the wheels down even better.
Notice how all real race shocks use spherical bearings. Polyurethane give near metal to metal
results with less vibration and noise and unless there is rotation in the
joint, it will not need lubrication.
Two people have done this. One
said the ride was much rougher and the other could not tell a change. I'm sure that helped you.
Very
often people ask what other shocks do better (stiffer) than stock for less
money than Bilstein. Years of knowledge
from the hundreds of CV & GM enthusiast has lead to the following list:
Gabriel LT (1 driver) $18-$20
Edelbrock IAS (There is very positive feedback on
the newest models and all say they are not harsh) $??
Ford PI (1 driver felt it got most of the float out)
$22
End
of list.
Don’t
ask about Marauder shocks. They will
not fit. Marauder shocks should have
the perfect blend of ride and control.
They rear shock mounting points have moved to the outside of the frame.
Ok, for more money what is
there. You are now stepping into new
territory. The only place left to go
are separate rebound/compression, low speed adjustable & reshimable shocks. No one has gone there to our knowledge with
CV/GMs. There is only potential for
improvement and I believe it is there in transit steering response. Long ago, experts believed shocks had little
control on cornering. Wrong. Around 91 or 92 Indy race cars learned about
the shocks offroaders have used for centuries.
In recent years Auto-X racers have adopted this technology too. We are talking about separate low/med/high
speed dampening, one way shim stack dampener and other spy stuff. You may also need someone with a shock dyno
that knows how to use it and knows how to tweak all those springs, washers,
orifices, and whatever. When you turn
the wheel hard the car leans, weight shifts, tires take a set in slip angle,
and more. The inside turn shocks must
extend while the outside shocks compress.
This takes time and there forth we call this transit cornering. It also gives the shocks time to work. If we set the shocks with different rebound
and compression settings, we can momentarily shift weight to wheels different
than what the springs and swaybars would do.
With our big cars the front tries to push with a quick jerk of the
wheel. With shock tuning we could get
the right tires working harder and faster.
Unless you are rich, an Auto-X racer, or just want an all out handling
CV/GM, then you would most likely find the extra work, money, and possibly ride
harshness a disappointment for what you get back. If you are still with us, then go to Koni shocks web site. Just remember that you want dual adjustment
for both rebound and compression. There
are also other shock manufacturers.
Research it. Don't expect big
changes, just the ability to fine tune.
Notes
for installation on all shocks: Take it
easy on the lower front shock bolts.
There are no nuts ... just the thin soft stamped sheet metal lower control
arm. I learned the hard way. The top nuts use a 9/16" wrench or
socket. The top of the shock can be
held with a #9 spoke wrench or a ?/?" wrench. To speed up removal, you can cut the plastic guards, slide them
down, and vise grip the shaft so you can remove the nut. If you take this short cut, the old shocks
are history. Also use penetration oil a
few days before work. You will cuss the
access to the rear shocks upper nut. It
requires a long wrench and you can turn it very little. This will require a lot of patience (beer).
Swaybars:
Next
are swaybars and Addco is the only one there for us. The part numbers are:
Addco
front swaybar #509 1 1/4", about
$90
Addco
rear swaybar #650 1", about $90
Energy
Suspension ENS-9-5165G 1 1/4" "C" clamp w/grease, $13.95
Energy
Suspension ENS-9-5161G 1" "C" clamp w/grease, $13.95
New
front end link - ENS-9-8124G x2, 3 9/16"
$13.95
Addco/Energy
Suspension endlink bushings for rear - Package of 8, $7.95
98
Stock rear bar ?" next to Addco's 1"
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|
I
can help you stiffen the ride. |
"crownvic96"
Without Addco Swaybars. Not to bad, but
room for improvement. 
Addco
quality is satisfactory and the results are always very worthwhile. Everyone has been glad they did this
upgrade. They are very modestly priced.
Addco increases the front bar roll resistance about 52% and 71% for the
rear over the 98+ HHP bars and more on the rest. This is done with a 1.25" front bar and a 1" rear
bar. So far 100% of us have mounted our
bars on urethane or polyurethane bushings.
The ride will noticeably tighten up.
This is more noticeable on rough roads.
You can always substitute some of your old rubber endlink bushings with
the urethane/polyurethane bushings till you get the ride you want. I have never heard of a person complaining
about the ride with 100% rubber. You
can still get about 75% of the improvement with all rubber. Nothing does more to make hard cornering fun
than swaybars. The tire wear improves,
tire squeal changes to a growl, and the car stays much flatter in the
turns. You do get some improvement in
cornering power. This is the one
handling modification that puts more smiles per turn than anything else.
The
stock 98+ HHP bars are not too bad with stock tires. Just replacing the stock bushings with urethane/polyurethane
helps some and does not change the ride.
This is very cheep with a modest improvement. Cost is about $37 if you hunt around.
Mounting
is done with either Energy Suspension polyurethane bushings or Addco urethane
bushings. With either you only want the
"C" clamp bushings with grease fittings. Only Energy Suspension comes with them, but they also have them
without so be careful which ones you order.
With Addco, you will have to drill, tap, and cut a grove. If you do not have grease fittings, you will
soon hear the dreaded dry bushing squeak.
Addco tends to be over priced with their mounting hardware. They do have a good deal on the endlink
bushings. These can be bought at
Advanced Auto Parts and other parts shops.
Do note that Ford's rear "C" clamp is not a conventional two
bolt set up. Some people have drilled
and tapped for a second bolt. Some have
inserted a 3/8" spacer under the urethane/polyurethane bushing and reused
the stock "C" clamp. 
This
requires that a grease fitting mount be drilled and tapped. Also the grease fitting will need to be long
threaded as the Ford's "C" clamp has a reinforcing ridge running down
the middle creating a gap. Energy
Systems rear "C" clamp will not bolt up without modifications. Addoc's will bolt up but it does not have
grease fittings. We have one known
failure with this "C" clamp.
No matter what the rear will require some work or risk the dreaded dry
urethane squeak from lack of lubrication.
Suspension friction = poor ride and handling.
Addco
has in the past forgotten to add all the instructions. They have had fatigue problems with the
stock front endlinks. They now have a
new front endlink that bolts to the lower "A" arm. There is an existing unused hole in the
arm. The hole is punched so the edge is
very sharp for the plastic bushings. I
would recommend grinding the ridge down and adding a small radius to the
hole. The link is ?" long.
There
is a down side to Addco's endlink replacement.
The following is a quote from a Ford engineer on their ball jointed link
directly connecting to the spindle:
” We attach with
a ball link directly to the spindle since 1991 Town Car. We call this a 1-1
stabilizer bar attachment. It is much much more efficient than attaching to the
lower arm with rubber insulators, like some do, and we did for years. Of course
the ball attachment is more expensive, but the effects on steering response and
transient roll control are dramatic."
The
Ford engineer was very confident on the durability of their endlinks. Still, safety comes first.
Because
of the data making the stock endlink desirable, a letter was sent to Addco to
verify the problem. Here is the reply:
Dana,
I have not heard
of any problems we have had with endlink failure. I have asked around the
office and no one seems to have heard anything either. I'm not sure who sent
you information indicating there was a problem but as far as I know there isn't
one.
Let me know of
any further information you can get me and I will do the same.
Dan Osborne /
Vice President of OEM Operations
ADDCO Mfg. Inc.
1596 Linville Falls Hwy.
Linville, NC. 28646
Phone: 800/621/8916
Fax: 828/733/1562
e-mail: dosborne@addco.net
A
second E-mail was sent with the original installation sheet. With no reply, I spoke to Dan Osborne on the
phone.3-26-02. Dan is now saying not to
use the stock front end links. He could
not expand on the change in his response.
Don't
ask me what to do. This has left me a
bit confused too. These are the facts
as they are.
The
PI CVs have clearance problems with the front Addco bar because of the oil
cooling lines. I have not looked at the PI models to see what the problem
is. If the stock 1 1/8" bar
clears, why would Addco's 1 1/4" not?
Well the word back to me is the arms have a different bend. Energy Suspension does make tall mounts as
well as standard. Also the endlink
height could be adjusted some. Maybe
between the two, it can be done. I would think that the oil lines could be
rerouted. I don't have a PI so I don't
know. Do NOT mount just the Addco rear
bar alone! That would make the car tend
to spin. This is especially true in the
rain. This is not theory as several
people have reported their cars handling dangerously with only a heavy duty
rear bar. Addco says this too and so
will I.
See
Bada Bing's web page on installation with some great pictures. Thanks big guy!
http://home.swbell.net/jorem/addco_sway_bars.htm
Some
people have reported that Addco uses a poor grade of steel. This may be true and would help explain
their low prices. However all steels
have the SAME spring rate. Using a
lower quality steel would only be a problem if you twist the bar to its yield point
or close. If Addco's bars were reaching
the yield point, I would think it would be only a short time till they
break. You just can not bend steel back
and forth with out it very shortly breaking.
I just don't think our cars have enough suspension travel to twist the
bars to their yield point. Besides,
Addco are the only ones there for us and we have never had a problem.
Rim widths:
This
comes second to tires on pure cornering power.
Radial tires are sensitive to rim widths and they DO respond to it. Wide rims speed up the steering response
noticeably! A wide rim is a great
foundation for the tire. This is
especially true with heavy cars. I believe it also lowers the optimum tire
pressure. Lower tire pressure means
more rubber on the road. You should
also get better tire wear. If you
research the tire you are buying, you should have found the approved rim
widths. Sometimes you will see wording
like, "Recommended rim width".
This may be true, but is only true when keeping it conservative on
ride. It really should say rim width
used for tire measurement and many do this.
For maximum cornering power, reduced slip angles, best steering
response, pick the widest rim width.
The ride will degrade noticeably.
This happens mainly on sharp edged bumps. You should notice very little with normal road bumps. For most 245 x 50 x 16 tires the max rim
width would be 8.5" and for 245 x 45 x 17 tires this would be
9". This is an additional
1.5" to 2" over the stock 7" rims. Where are you going to put it?
On the inside you have an upper ball joint that hits first and in the
turns it is the front swaybar. It only gets worse with 255 tires. The rule of thumb says overall width goes up
.4" for every additional 1" of rim width. If I wanted performance over looks, I would go with 225 tires
over 245 or 255 if it meant loosing rim width.
It helps that much. You ask how
wide it best for cornering power? The
width of the tread is a good rule of thumb for the width of the rim for max
performance.
There
are two down sides to a wheel too wide (exceed recommended rim width). First the cornering power will start to
diminish. Second the flexing of the
sidewall will move down closer to the bead.
The bead area is thicker and will not tolerate this well. Heat will build up and the tire may
fail! At the same time if the rim is
too narrow, the flexing will move up to the tread area. Again the rubber is getting thick and heat
will be generated. Excess heat can
cause tire failure. The manufacturer's
guide lines for approved rim widths should work fine. Use the recommended rim widths and everything will be fine. That
also means that even the widest recommended width should not be too wide for
maximum cornering power. Maximum
cornering power hits typically when the rim width matches the tread width.
The
heavier a vehicle is, the more important it is to have a good foundation for
the tires. Our cars are very heavy
compared to sports cars.
On
the down side, rim width has a direct affect on the ride. Also the rims will be moving out from the
protection of the tire. It will be
easier to scrape a rim on a curb. If
you have scuffmarks on your rims now, then this may not be a good idea. My mom's car is a great example for not
needing wider rims. Lol! That is something to think about before
loaning out your car.
Here
are some Tire Manufacturer links on this subject.
Dunlop:
http://www.dunloptire.com/tiretech/?article=tire_width.txt
If
all those tire size numbers did not register, click here for tire numbers 101.
http://www.howstuffworks.com/tire2.htm

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Scrub radius: |
|
X Racer, you got me all
dirty ... Now you have to scrub me too! |
This
is also called Kingpin offset and Pivot Radius. This is simply the distance from an imaginary line drawn through
the ball joints till it hits the ground and the center of the tire.
|
|
This
imaginary line is what the tire pivots around when you turn the wheel. Most of the time it is 1" to
1.5" inches on rear wheel drive cars.
It is also the leverage the wheel has against the wheel in your
hands. Think of it as a wrench
1" to 1.5" long trying to fight you when driving. The good thing is
you should have a second wheel on the front of your car balancing things
out. Every time one wheel hits a deep
water puddle and pulls on the wheel, this is the lever pulling against
you. Same thing for brakes that pull.
It is also what gives you much of the "road feel" sensation when
driving. Why are you telling me all of this? Because on most cars all the added rim width will have to go to
the outside. Going to a 17" x 9" rim may add at most 1" to the
scrub radius. This is a 100% to 67%
increase. The wrench just got longer. Every water puddle will pull twice as
hard. |
That
brake job that was over due will be twice as bad. Our cars appear to have good room on both sides. CV/GM cars have
some of the poorest road feel and the strongest power steering units around. I
don't think we have too much worry about.
The only time I was mildly disappointed in the scrub radius change was
when I jumped from a 5" wheel to an 8" wheel with manual steering.
You should be able to add 1" more rim on both sides keeping the scrub
radius the same if you use nearly the same offset. Where do you get the data to mount wider wheels? All any tire shop will do is add all the
width to the outside and it is your problem if it hits the fenders. Most front ends are tight on the inside
anyway so their brainless method is right most of the time. Can
you tell me what clearance you need? Sure,
here is the formula. Just factor in the
tire coefficient of friction that generates the cornering forces that compress
the rubber "A" arm bushings, bows the spindle, twist the frame,
flexes your wheels, and off sets the tire on the rim that air pressure and rim
width also affects. It's just that simple! Ok, it is too complicated with to many variables. Adding it all to the outside is safe except
for the fenders. 8" rims appear to
be very safe on our cars. With a nearly
stock offset, 9" rims should work with 245 tires. Most likely 255 tires will squeeze by. Several people have used up to 275 tires on
the rear. I am not sure what rim width
they used. Wider rims do affect the
overall tire width. Obviously it has no
affect on tread width. If you want to
go wider, ask yourself, "am I ready to flare my fenders to make the tires
and wheels fit if there is a problem?"
I am not talking about 5" fiberglass flaring like some road racer
with tires 12" or wider. I am only
talking about folding the inner lip and then maybe a body man massaging and
extra inch or so into the metal, if anything is even needed. I have done this before and it is no big
deal. You will also be widening the
track width and this tends to help cornering power. "If" you feel the increase in the scrub radius
adversely affected the handling, then you can tighten things up. Many wheels companies machine the center
section of the wheel down for different offsets. Check to see just how much they approve. Second, place some clay on the tight fitting
areas. This would again be the upper
ball joint and the swaybar. The swaybar
only hits in full lock turns and is not sharp.
This should do little harm if they bump from time to time. Just don't crank the wheel with a lot of
pressure at full lock. When it stops
turning that is it and let up. The ball
joint is the key, but don't trust me.
Get in there and look around. It
could be the brake calipers. Anyway
pile the clay on and go for a drive.
Hit the roughest and hardest turns you know of. When you are done, measure how thick the
clay is. You could do this with the
stock wheels to see just how much room you have with the fenders. Just remember that the tire only moves over
half the rim width you are adding and the center bulge only moves .4" for
every 1" of rim width over the wheel used to make the tires
measurements. This is listed with the
approved rim widths. This peak bulge is
not at the edge of the tread. It is
even further away from the fender. Also
do not eye ball the fender clearance.
The top of the tire is pulled in by the shorter top "A" arm
giving even more clearance. Adding say
1 degree or more negative camber will also add fender clearance. Clean the parts and with a little luck the
clay will stick. Once you know exactly
how much room you have, take the wheels to a machine shop and machine the
mounting flange down to your new specification. Keep the changes small or go buy a new wheel with a different
offset. Spacers are frowned at, but up
to a 1/4" is safe with longer studs.
Don't forget, if you are testing with a tire with a lower performance
level than you plan to use in the future, deflections may be less. The "Watts Link" used on 98+ CV/GM
cars does a better job of locating the axle laterally. Obviously this means on pre 98 vehicles you
will have to have more clearance or replace the control arm bushings with
polyurethane to firm things up.
Ok, is there anything you do
know for sure? Yes, on stock 15" x 7" 10mm offset
wheels (pre98s), 255/50/15 tires will fit with some slight dragging on the
swaybar and the plastic by the footwell, but only at full lock. With 255/50/16 tires with stock 7"
wheels (98+), other owners say they clear.
My 245/50/16 tires on stock 16x7 10mm offset wheels cleared until the
Addco front sway bar was installed. It
took awhile, but plating is wearing a tad.
Again this is only at full lock.
We have a few members who have used the 17"x8", 25mm offset
Mustang Cobra wheels with 1/4" spacers.
Mustang wheels normally do not fit without spacers. Cobra wheels are
17" in diameter and 8" and 9" in width. With stock 16" wheels, it looks like we
have 1.75" of clearance on suspension parts. You should not have any problems with 8" width wheels, 9" may be tight and I highly recommend
17" wheels on any car with 98+ brakes.
I have yet to find a 16"x9" wheel that will fit. Currently I am running Ford Cobra 17x9
wheels with 1/4" spacers. More on
this four paragraphs down.
The
Tire Rack (www.tirerack.com)
has a 16x8 wheel for our cars. Cheap, easy,
and you know it fits.
The
stock wheels use a 10mm offset and the new appearance package Crown Victoria's
use a 12mm offset. The max backspacing
appears to be 5.5" that will fit.
If
this is not complicated enough, a college did a study on the affect of scrub
radius on cornering power. They
designed a custom adjustable spindle so that they could play with the scrub
radius and not affect any other measurements.
They took it all the way to a negative scrub radius. Their test showed that the cornering power
went up a full 0.1G with a negative scrub radius over about a 1.5" scrub
radius. Remember they adjusted the
scrub radius without changing the track width.
Adding track width normally improves the cornering power. I noticed that the skid pad was very very
tight. I would guess near full lock on
steering. Also the test were done with
a SUV. Still 0.1G is a big jump. They said nothing about the stability on the
highway. The old school of thought is that wheels that widen the track help
cornering. This makes you think about
it twice. Once again, this data does
not lead to a clear answer. I never
said I knew everything and if someone claims to; RUN!
Ford Cobra 17" x
9" wheels and Kumho ECSTA Supra 712 245/45/17 tires:
As
of June 2002 I have not found a wheel under $1000 each that is 9" or more
and will fit our cars. That does not
mean it does not exist, but I searched for months. I did find a 16x9 wheel with a near perfect offset that would
work on any pre 98 car. Even though it
will mount a 16" tire just like a stock98+ CV/GM stock wheel, the inside
wheel diameter will not clear the 98+ brakes.
The only thing I have found is 17x9 Cobra wheels with 1/4" spacers. I would think twice about using replica
Cobra wheels. They tend to weigh more
and if you ever dent/damage a wheel, you have no guaranty the company will be
around for a match. Ford will be here
tomorrow. Also the best price on each
is very close. Tire Rack had the best
deal at the time of my purchase. The
Cobra 17x9 wheel and tire added 5lbs per wheel over the 16x9 wheels I
found. Even these were about 9 to 10lbs
over the 16x7 HHP wheels with near bald tires.
Obviously, this is no way to improve your 1/4 mile times. Also the extra weight is toward the outside
of the rim. This is a modification for
handling and not for acceleration. Even
with 1/4" spacers, the offset is a tad less than stock. Between new full treaded tires and less
offset, you can feel that the steering is lighter. It was light enough to begin with. I chose Kumho ECSTA Supra 712 245/45/17 tires. They are not the best Ultra performance
tire. But they are near the top. I did compromise a tad to gain better tire
wear, reduced noise, wet traction, and ride.
A 50 profile tire would keep the diameter closer to stock. The Cobra center hole is perfect for our
cars. The hub that fits into the hole
is rather short. I have concerns as to
if the two even touch with the 1/4" spacers. A 1/8" spacer may work.
I need to pile some clay in a few places and see just how much room I
have. I would highly recommend longer
studs any time you use a spacer. Summit
should have longer wheel studs.
That's a lot of details, but
how did it perform? The steering is noticeable
more tight and a tad lighter. Cornering
power is way up. The tires will not
squeal until clearly over the edge. It
is more of a whooshing sound in the turns.
The back and front end used to have different ideas on what they wanted
to do. Now the rear end follows the
front with absolute precision. It is now
boring to drive because it is so easy at normal speeds. You feel like you have less control on speed
as the car no longer responds to the throttle much. What I mean is if you take you foot off the gas when turning
hard, she will not slow down nearly as fast.
The scrub is greatly reduced.
This is free HP. Less scrub means that if you screw up and get to hot in
a turn, you are in real trouble. Plus
the speeds are way up. A public road
can no longer be used to the limit even when no one is around. The speed is just to fast. With the old set up, you only had to hold on
for a few seconds and the speed would scrub off fast. The ride is much rougher on sharp edged bumps. Rounded bumps are virtually the same. It is almost the same amount of ride change
as when the Bilstein shocks were installed.
If your butt meter likes it smooth, then stick with a 8" max width
rim and no lower than 50 on the profile of the tire. The ride is still very quiet.
Many people say some of the very best of the Ultra Performance tires
tend to be noisy. Tire Rack post
owner’s opinions good or bad. The ride Vs performance with this tire/wheel
combination is not as favorable as expected.
The body rubber mounted on the frame does a great job of reducing any
harshness that modification can cause.
Evidently, you can push this rubber too far. My butt meter is at its limit on harshness. Our cars will never be race cars so me
there is no reason to totally kill the ride.
But I am getting a little older.
Someone in there 20's may say, "What’s next?" But at the very beginning I said much of
this is personal and subjective.
I
have played with the tire pressure some.
Dropping the air pressure to34psi front and 32psi on the rear seems to be
helping and I feel both ends take a better set at the same time in a turn.
Alignment:
Camber: For peak cornering power, cars need negative
front camber. If you are wearing the
outside edge faster than the rest of the tread, then this is a win win improvement. With our cars, you most likely have a
suspension problem if you are wearing uneven.
Especially with a 98+ car. They
take abuse very well. While adding
negative camber helps cornering by keeping the tire flatter when the car leans,
it also increases the camber change when using the brakes hard. You may loose a tad in braking. For peak performance, most radial tires like
2 - 3 degrees of negative camber. Most
street cars run 1/2 - 1 degree as a reasonable compromise. If you are wearing the outside edge, then
keep cranking the camber in. Cornering
power will go up and uneven tire wear will go down. It also may be time for HD swaybars and/or "A" arm bushings
if you are wearing the outside edge badly.
98+ CV/GM cars handle hard cornering with even tire wear. Thank you Ford.
Even
the rear tires like camber. If you are
ready to go 100%, you can torch the top of the rear axle making it warp. This is how many NASCAR and other solid axle
race cars add about .75 degrees camber to the rear. Anything more and you have to modify the axle splines. Also bearing, axle, and differential wear
goes up. This would make this
modification rather drastic with little return. This would be cool for a dedicated Auto-X car and not much
else. That eliminates about 99% of us.
How much gain in cornering
power does 0.5 to 1.0 degrees camber give you? If you can find the data, then let me know. Experts only say it helps. Handling is part science and part art. Every vehicle and tire will be different.
Toe-in: Our cars are slow to initiate a turn. Setting less toe in will help. I have tried toe out before and the car (not
a CV/GM) was still fairly stable. Wide
tires tend to add stability too. Going
toe out is a trial and error method.
The car may become darty, and braking may be more unstable. Front end condition and tires can have an
affect. Experiment with caution is the only advice with toe.
Castor: Castor adds stability and helps with
straight line stability. It also
affects trail. Trail is the same as on
bicycles and motorcycles. Castor is
more like the fork angle. Just like
with two wheel vehicles, increased castor and trail increases stability. It also may slow down turning. With four wheel vehicles, it adds negative
camber to the outside tire as you turn the wheel. This can help keep the tire flat in the turns and or help add the
negative camber needed for maximum cornering power. Trail changes with castor changes. There are no separate adjustments except for casting/forging your
own spindles.
Tire loads Vs Traction:
This
makes all the difference in the world to cornering power! Lighter is better. If you take a tire and apply a 500lb vertical load, you would
likely find it could handle a 500lb side load.
That would be the same as turning 1G!
That would be great. Now if you
place a 1000lb load on the same identical tire you would hope to get the same
ratio and get a 1000lb side load.
Nope! It would be closer to
850lbs or about .85G. That is no where
close. Our tires are running about
1100lbs on the front and about 900lbs on the rear empty! Yes they are big cars! From hear it goes down hill.
Weight shifting:
Our
cars sit a tad high and we get a fair amount of weight transfer from the g
force of a turn. You could easily
transfer with good tires about 80% of the weight. Lets play with some numbers.
Take a 3950 lb Grand Marquis with 12 gals of fuel and a 200lb driver and
CV/GM's 55%&45% front to rear weight split. This would place about 1858 lbs on the outside front wheel and 1520
lbs on the rear! The inside tires would
be running about 464 lbs and 380 lbs.
Note the rear inside wheel weight of 380 lbs and then think of trying to
put power down threw an open differential.
Can you say wheel spin! This is
just an example and we do not have any real data to show real weight transfers
and which end of the car is doing the most roll resistance. This is controlled by the sway bars,
springs, track widths, and more, but then taken away by frame flex. Many front wheel drive vehicles lift the
inside rear wheel right off the ground in a turn. Porsche rear engine cars tend to lift the inside front wheel off
the ground. This shows how cars react
when the front to rear weight bias is way off 50/50. The best performance with a given tire is when all four tires
work evenly and at the same time.
However, racing has shown weight distribution close to 40% front and 60%
rear on rear wheel drive works best.
The fact that our inside tires are very lightly loaded and can withstand
higher G loads as shown above, does not make up for the highly loaded outside
tires that we know can not corner hard.
Not even close with say 20% of the weight in their corner. The poor performing 80% of the weight or
whatever will dominate.
Lets
see what we can do to balance the traction.
Try to imagine a car with only one large sway bar at one end and nothing
at the other. Most all the weight
transfer would be carried by the sway bar end and it would be massive or even
100% as in cars that lift a wheel. The
non sway bar end would have both inside and outside tires working together with
nearly the same load. Guess which end
will have the most traction. Yep, the
non swaybar end. This is how we tune
our cars. If one end of the car is
loosing traction before the other end, we can shift the traction. Our cars are heavy in the front and lighter
in the rear. About 55/45. They also come with a rather large front
swaybar. Our rear track width is about
65.3" Vs 63.4" on the front.
All of this tends to make the front push. Addco bars are 40% stiffer in the front and 70% in the rear. This will shift the traction from the rear
to the front so that all four tires are working more evenly. We call this a balanced car when both ends
work equally. The bars also keep the
tires flatter on the road by reducing body roll. This all adds up to more cornering power. The stiffer rear bar also transfers more
weight off the inside rear wheel making it tougher to accelerate out of a
turn. Our cars are not all that
powerful so the wheel spin is not much worse than the stock set up before
Addco. Our CV/GM cars have a big
problem with frame rigidity. The same
body on frame with rubber mounts that makes our cars so smooth and quiet also
lets everything flex. It is hard to
adjust a sway bar and get the chassy to respond because the frame flexes
instead shifting the weight like we wanted it to. Again, a Panther platform car will never be an ultimate sports
car. Just better if you want it to be.
So what if you go threw a
turn so hard that nothing is left to put power down threw an open differential? You are going so much faster than the other guy that he will
never catch up. The only real fix is a
limited slip of some sort.
Adjusting the cars balance
If
the car is pushing (to tight, understeering) to much, try the following:
More
front tire pressure
Less
rear tire pressure
Smaller
front swaybar
Softer
front swaybar mounts
Larger
rear swaybar
Stiffer
rear swaybar mounts
Wider
front tires
Wider
front rim widths
Shift
weight from the front to the rear
Use
softer front springs
Use
stiffer rear springs
Use
softer front shocks
Use
stiffer rear shocks
Widen
the front track
Narrow
the rear track
Use
a softer compound tire on the front.
Use
a harder compound tire on the rear
Reduce
the roll axis angle by lowering the rear center of roll (rear is normally
higher than front)
Reduce
toe in on the front (toe out may be unstable)
Add
more front camber
Reduce
scrub radius (may only work on tight turns)
Reduce
kingpin angle without increasing the scrub radius (only works on tight turns)
If
the car is oversteering (loose, trying to spin) too much, try the following:
Do
everything the opposite as shown for understeering. If that does not work, lift your right foot a tad off the right
pedal.
Reducing weight shift in the
turns, Ride Height, Springs:
Obviously
we have learned so far, that anything that reduces weight transfer in a turn
and helps all four tires work together in a turn will also help cornering
power. The easiest way to reduce weight transfer in a turn is to lower the
car. The air ride rear suspension cars
are easy. Just loosen the ride height
sensor, slide it over away from the differential, and retighten. Done.
This is only on the rear on some of our cars. They all have coil springs on the front.
With
springs there are two ways that are cheap.
The easiest is to cut the spring down.
The problem is it will also make the spring stiffer. If you cut 1" worth of spring you may
only get 3/4" lower. 1/2 to 1 coil
is about all you can get away with on our cars. This is a bit of trial and error. Just go slow because you can not add back what you cut. One
member reported about a 2" reduction in ride height with 1 coil cut. He also felt the ride was noticeably stiffer. He strongly recommended starting at 1/2 a
coil to start with. He said that the
camber adjustment was maxed out during the realignment.
The
second method is to use the same spring compressor that you used to remove the spring.
Compress the spring as far as you can.
Then place it in your oven at 450 degrees for say about 10 minutes. Remove and recheck the length. You did measure it before baking it? Keep increasing the time till you get the
desired results. There is no data on
baking time. So go slow or risk messing
up a spring. This is a great way
because the spring rate does not change.
It is also a trial and error method.
Again, go slow. The toughest
part is getting the left and right the same.
Just make sure you compress the left and right springs the same and use
the same oven time. They should come
out the same. If not just cook a tad
more on the long spring. The low 450
degree temperature will not alter the heat treatment. Some people use a torch directly on the springs while on the
car. This is a BIG NO NO. It also gives the oven method a bad
rap. Jumping from 450 degrees to about
1500 degrees or more will mess up the metal grain structure, temper, heat
treatment, or whatever you want to call it.
The oven method will not change the spring stiffness and there forth no
ride change.
The
third method is to spend your hard earned money on after market springs. Most after market springs are stiffer. Same or close to a cut stock spring. Increasing the spring stiffness is one of
those modifications where the handling increases very little, but the ride
takes a big dive. Remember that stiffer
springs work similarly to stiffer swaybars.
It can change the balance of understeer and oversteer.
I
would NOT lower a CV/GM without much better shocks and HD swaybars. Car lean and weak shocks can use up most of
the suspension travel leaving you little for the bumps in a turn. You do NOT want to ride your bump stops in a
turn! This will kill your car's handling. Some people try stiffer springs to stop
bottoming and dragging the car.
Offroaders use compression dampening in the shocks as the primary method
for bottoming control. This is catching
on with street vehicles. Both stiffer
springs and stiffer shocks reduce bottoming.
But stiffer shocks hurt the ride less.
Stiffer springs will kill the ride.
For maximum traction, you always use the softest spring you can
use. Again, Bilstein shocks do a great
job at this and they are matched to the stock springs. Stiffer springs may throw off the rebound
setting Bilstein designed. Just don’t
know. Here comes the down side again. When you lower a car using the springs, you
change the "A" arm geometry.
This may hurt the handling more than you helped it. Not often, but it can. Also you are loosing some of your
compression travel. Hopefully, better
shocks and swaybars will keep this in check.
It has on mine and other CV/GM drivers.
There
is a forth way to lower your car. Just
buy low profile tires with the stock diameter wheels. This will lower your car, gear her down for better out of the
hole power, increase braking power, improve the sprung to unsprung ratio, the
tire profile is lower, the steering response is better, the control arm
geometry is unchanged taking the risk out there, the rotating inertia is
reduced, and you will still have full compression travel in the
suspension. Wow! For the down side, smaller diameter tires
will lower your gas mileage just the same as if you changed your rear end ratio. The same thing happens to the
speedometer. And just the same, you can
buy a new speedometer gear and/or burn a chip to bring the accuracy back in
line. Also anytime you use low profile
tires, the rim is closer to the ground.
This will degrade curb and pothole damage resistance. Last, the car will be lower when the bump
stops are reached.
And
you thought we were out of methods.
Lol! Here comes #5. Another trick is to replace the frame to
body rubber mounts with a stiffer and lower mount. This will hurt the CV/GMs great ride. This method also ties the body and frame together adding
rigidity. This helps a lot when it is
time to use sway bars and shocks to tune the car's balance. This is rather extreme for most of us. This method keeps your ground clearance and
suspension geometry the same. Note: The
gas lines pass between the frame and body by the drivers side rear wheel. Check for wiring, engine, transmission, etc...
clearance and interference problems first.
You could say forget the bushings all together and bolt the two
solid. I have noticed that all large
trucks lay a piece of wood between the frame and body. I would think this was to keep from rubbing
metal on metal. Also welding lumps and
such could be imprinted into the wood Vs steel that is not so good at it. Kind of like a gasket making up for
irregularities. 95-97 Impala owners
have gotten great results in handling by messing with the body to frame bushings. No, CV/GM owners have messed with these
mounts to date. This would be new
ground to break for us.
If
you do lower your car using the springs, expect the alignment to change. You should find more negative camber. That will help cornering and most likely
cause uneven tire wear.
The
track width also plays an important part of the weight transfer. Making the car wider helps. The only real option is with wheel offset
and width. The down side on scrub radius
is covered under wheel widths. The only other way is custom control arms and
spindles. Can you say $$.
Anything
to get weight off the front will help.
Remember that the more even the tire weights, the better their
performance. More rear weight also
helps acceleration off the line and braking potential if you readjust the
bias. Moving the battery to the trunk
will shift a little under 1% of the weight and lower it and get it out of the
heat so it will last longer. Pre 98
cars have aluminum bumpers that may weigh less. We have not compared to know.
Exhaust systems have been upgraded to improve power and they tend to be
much lighter. Trailer hitches add
weight. But, I have things to tow and
that adds 40+or- lbs to a bad spot. A
mini spare can knock off 15 to 20 lbs.
Mustang Cobras use a light weight mini spare that may work on our cars.
Spring
and ride height data from Ray Bones.
Great work Ray!
From Ray Bones:
The spring rate is different (HPP = 102
lb/in, base air spring is 89 or 75 depending on year). They are a direct plug
in for each other, ie no vehicle modifications required. HPP springs have a
firmer ride and are harsher. Handling will be a little different.
--------------------------------------
Spring rates for the
pre-03 non-HPP CV (P73/74) - Front=440 Rear=130
Spring rates for the pre-03 CV PI (P71)
- Front=700 Rear=160
Spring rate for the pre-03 HPP - Front=560 Rear=Air 102
---------------------------------------
Base air springs EN & FN 1990 -1997
(75 lbs/in) Cream piston and cream cap, HPP air springs all years (102 lbs/in) -
black piston and cream cap, Base air springs 1998-present (89 lbs/in) cream
piston and black cap.
--------------------------
Aprox. rear metal to metal travels at
curb.
Jounce Rebound
Base = 5.5 3.9
HPP = 5.1 4.3
Police = 6.3 3.1
-------------------------------------------
Mercury Marauder uses the HPP rear air
springs. Front springs are 325 lbs/in (do not compare directly to older cars
spring rates due to different motion ratios). Shocks have much more effective
damping than the older car you are talking about. Also Mercury Marauders have
less suspension travel in order to protect package space for the larger
tire/tire package.
Slip angle:
When
we turn the wheel we assume the tire contact patch turns with it. However our tires are very flexible with the
massive weight they have to support.
When we corner, the contact patch is turning a different direction than
the wheel. We call this the slip angle. It does not mean we are sliding on the
pavement. This is easy to see in a
parking lot. With the engine running, stand outside your open window. Apply pressure to the steering wheel till
you can see the wheel turn. Then
release. The steering wheel and rim
will spring back in place. Keep doing
this till the tire contact patch slips.
If the tire slips, the steering wheel will not return to its original
position. This is the maximum slip
angle for your car. At least in the
parking lot with no weight transfer.
Anouther way is to go to a large empty parking lot. Turn the wheel to lock. Now make a slow turn. Keep speeding up and note that the car keeps
making larger turns. You have not moved
the steering wheel, and the tires are not sliding. Yet the side loads are reducing the effective steering angle
making for a bigger turn. Just say slip
angle.
Engineers
make sure the front lets go first for safety reasons. That also means that the front slip angles are much greater than
the rear. When we add Addco swaybars,
the slip angles are much more even. We
get a slip angle on the front tires by turning the wheels. So how
does this work in the rear? The
whole car must turn side ways to get a slip angle. When Addco added about 70% more roll stiffness to the rear bar Vs
40% for the front, they induced more slip angle on our rear tires. This does mean you will go threw a turn more
sideways. Lets say it was 5 degrees
before we upgraded the bars. Now we may
see 10 degrees or more. Have you ever
noticed that race cars and imitation race cars have a large stripe front to
rear that is offset to line up with the driver? This is so the driver has a better visual clue as to how sideways
he/she is. Now if a cop pulls you over
for being sideways around a turn, I want you to try and explain it was just the
slip angle induced by the larger rear sway bar. Lol!
Slip
angle is heavily influenced by tire pressure, weight, rim width, tire profile,
and tire construction. Slip angle plays
a big part in what is called "road feel" and "feedback". It is what we sense when cornering
hard. The more slip angle in the front,
the easier the car is to drive and the more slow it gets. When we reduce the slip angle, it speeds
things up including trouble. Twisting
tires to high slip angles also takes up power. Have you ever noticed your car
slows down faster when turning hard.
Hence the term, "scrubbing speed in a turn". This well known fact has saved all of us
more than once when we over sped a turn and started getting into trouble. Turning hard generates a lot of heat and
that is bad for the tires. It takes HP
to generate heat and reducing the slip angle is FREE HP! High slip angles on the rear tires makes the
car move around a lot and it changes the front steering angles making you
adjust the steering. It also makes
running a slalom or making an emergency maneuver from one lane to the next and
back more difficult. Lets say you are
running Addco's bars and you have a 10 degree rear slip angle in a turn. That means the car must be 10 degrees
sideways for maximum cornering power.
To switch directions, you must set the car up 10 degrees sideways the
opposite way. This is a 20 degree
change. Do you think you can spin 4000+
lbs 20 degrees and have it stop instantly at the optimum slip angle with out
over shooting. NO WAY! Welcome to driving a BIG car with BIG polar
movement. By now, you should be getting
the feeling that a reduced slip angle will help and you are right. Tire rim width is the #1 method. Tire
pressure, tire construction, and tire profile also control slip angles. You do have Ultra Performance tires by now? Lowering the tire profile is why plus sizing
helps so much. It is more the tire
profile changing than the rim diameter although they both help. The tire contact shape helps and this is one
reason wider tires tend to help. Lets
hit the downside for a second. Slip
angles also give a lot of the feel and "forgiveness" that you sense
when driving. Less slip can speed up
things including trouble. This would be
a concern in a Porsche 914 due to its lightweight and very low polar
movement. Our sluggish 2+ ton machines
are so slow, you would have to be half asleep not to notice a spin coming on or
whatever. Obviously if you have
physical and/or mental incapacity's that would impede normal reflexes and
judgments, modifications such as everything written here would be a bad
idea. Also, if Friday night means
getting blasted and driving home, then high performance modifications would not
be recommended and jail time would.
Lol.
Tire pressure:
Tire
pressure has a major influence on slip angles, steering response and a fair
influence on traction. It also affects
ride. A tire has a pressure that gives
the best cornering power. You can go up
or down some without affecting it much.
Some as much as 10psi + or -. As
you go up, the steering gets faster and slip angles go down with less scrub in
the turns. Bottom line, higher pressure
tends to help. If you have already set
your car up with low profile Ultra Performance tires with maximum rim widths,
you most likely have all the steering response you need. Just find the optimum cornering power tire
pressure.
Auto-X
people have painted their tire edges with white shoe polish for years. The paint wears off and you can see where
the tire roll over stops. You may be
shocked how far your tire rolls over! When my tire pressure has leaked down, I
have made it easily over to the side wall lettering. They roll a lot, but you need to keep it on the tread. For maximum performance, you drop the
pressure till you start getting off the tread and then you go back to the last
setting that worked. If you are testing
hard, don't be surprised to see the pressure jump 5-10 lbs. Even though you may have found the ideal
cornering pressure, additional air may help lap times by improving the steering
response.
The
best way is to run the car hard, stop quickly, and check the tire temperatures
across the tread with a pyrometer. High
temperatures mean high loads. You shoot
for an even temperature across the tread.
This also means making camber changes.
If you own a pyrometer, you are a serious racer and can help write this
article so I don't have to do it all.
Lol!
Suspension bushings:
|
Our
front suspension uses unequal length non parallel double "A" arms
mounted on rubber. 98+ cars have been
revised and improved. When you corner
hard it applies massive pressure on the rubber bushings and rubber does what
it does best. It deflects. This allows unwanted suspension movement
such as the wheel leaning over and more vague steering precision. On pre 98
CV/GM cars, |
|
Energy
Suspension makes polyurethane bushings for the double "A" arms. Reports from fellow CVers say they work
well. It is very important for not only
ride but also handling, that all suspension parts work smoothly with the least
possible friction. I would highly
recommend you take the time to install grease fittings at each bushing. Reports back also mention a slight degrading
of the ride. Well duh, rubber is softer
than polyurethane, and so we expected that going in and so should you. The CV/GM body on frame does a great job of
maintaining the ride and noise level, with modifications. But don’t expect it to do miracles.
Steering response:
We
all like instant steering response. Our
massive cars do not lend themselves to this.
For good steering response, try the following: Low profile Ultra performance tires, Wide rims, Higher tire
pressure, Addco swaybars, Energy Systems "A" arm bushings, and work
on the Polar movement. Even the
Bilstein HD shocks help a bit. Update
pre 97 models to the newer steering boxes.
|
Polar movement: What is "Polar
Movement"? You got it with CV/GM cars
and a lot of it. More than most any
car on the road. You are also stuck
with it as it is very difficult to change and easy to add to. Here is polar movement. Close your eyes and think of a barbell
with 50lbs on it. That is 25lbs on
each end. Now bend over with your back and pick it up with your grip shoulder
width apart and without bending the knees. Now rotate it to the |
|
Sarah: "How's my
polar movement?" X Racer: "Perfect
Baby!" |
left
and right. Feel the weight. Feel the energy it takes to rotate it and
then the inertia that fights you when you try to stop it. Now reach down and slide the weights till
they meet in the middle. Now pick it up
again and try rotating it. You are
picking up the same identical weight and twisting the same identical
weight. But now the flywheel effect is
gone. That is polar movement. Our CV/GM cars are not just heavy, the
weight is well spread out. A mid engine
car is just like pushing the weights together leaving very little polar
movement. Notice the next time on the
road how all the European cars have very little overhang on the front and not
too much on the back. This should be
telling you something. Weight hanging
off the front hurts much more than the rear.
Now look at our cars. Lots of
over hang on the front and the back looks more like a school bus. It just goes and goes. When you turn a car, you are rotating it
too. About 8 rpm is typical. It takes time and energy to rotate our land
yachts. The poor overloaded front tires
have to do this job. The rear does
nothing till the front sets the pace.
Some how you have to not only rotate the car to start it turning, but
you have to add a little for the rear slip angles and then magically have it
slow down when you reach the rear tires maximum slip angle before the tire
contact patch starts skidding. No can
do she says. As a general rule you slow
down going into the turn and accelerate out.
The poor rear tires have that massive overhang rotating and then some
driver stomps the throttle at the same time he straightens the wheel. All that rotating inertia is still there and
power is being added. No wonder our
cars push the front tires going into the turn and go sideways trying to come
out of the turn. If you think this is
bad, try running one of our cars at an Auto-X threw a slalom. Everything may be hard to understand here,
but it will hit you like a sledgehammer in a slalom. Lol!
What
can you do about it? Ummm ... Obviously the toolbox, golf clubs, dead
bodies, or whatever in the trunk does not help, nor does the 40+ lb trailer
hitch at the extreme end of the car.
How about those 98+ steel bumpers.
Actually there is very little you can do. Just get the stickiest tires you can get and knock the slip angle
down. Addco sway bars help too.
Smooth
driving is a big key on our cars. On a
light race car you can get away with slamming on the brakes, suddenly
releasing, and then jerking the wheel into the turn. You will not win this way, but a light weight car can do it. With a land yacht, you must be smooth. You
ease off the brakes and start the turn at the same time. Peak cornering power just hits as the last
of the brakes is eased up on. This takes
time to learn. We all know what can
happen if you try turning with the brakes on hard. This is a skill, and the public streets are no place to learn.
The ones winning races use this method and the others lose. There is some great
stuff on the net about this driving method.
Use "friction circle" on your search and you will learn lots
about it. Here is a good link with
pictures: http://thundervalleyracing.com/features/tech/wolffriction.html
Some
say the definition of a smooth driver is one that keeps the car on the edge of
the friction circle. I would agree.
Power application is done just the same. Our land yachts demand this sort of driving. Anything else will be screeching tires and
be slower.
Sprung to Un-sprung ratios:
This
simply means if part of your car moves with a bump in the road, it is
un-sprung. If it rides on the springs,
it is sprung. One end of the drive
shaft moves with the suspension and the other end does not. So only half counts. Same with shocks and control arms. Silly Ford mounted the rear swaybar to the
rear axle. Dumb. The HHP wheels are 10 to 15 pounds lighter
than the steel wheels. That is per
wheel! Major gains here. This sprung to un-sprung ratio has a great
affect on ride, but also some affect on cornering power. This is much truer on rough roads. Wheels are about the only major thing we can
do about this. If you can find the
data, many tires list their weights.
Some claim to be a few pounds lighter than others. Although there is little you can do about
it, it is here because so many people are building police replicas using the
heavier steel wheels.
The
stock 16x7 HHP wheels with TA 245/50/16 tires that are worn out weigh
39lbs. Some 16x9 cast alum. wheels with
Supra 721 245/50/16 tires and full tread weighed 49lbs. The stock HHP wheels are fairly light. With some poor scales a Ford Cobra 17x8
wheel weighs 20lbs. Larger diameter and
wider wheels drive the weight up.
Here
are some links to wheel weights:
http://home.earthlink.net/~cvlocas/wheels.html
http://www.miata.net/faq/wheel_weights.html
http://iquebec.ifrance.com/isrcrew/wheels.html
http://members.aol.com/ret2xanadu/lightweightwheels.html
Aerodynamics:
If
you are going fast enough to need this, you need to be in jail away from all
the responsible adults on the road with their babes and loved ones. Lol!
We could look from the angle of gas mileage. A belly pan is the number #1 way to clean things up. Lowering the car reduces the frontal
area. Enlarging the chin spoiler helps
seal off air from the dirty underside.
Some feel it increases the frontal area and hurts more than it
helps. I find that a little hard to
believe till I see data. The 92 Crown
Victoria is the best on aerodynamics due to the sloping no-grill front end.
Reports
say that a Ford Taurus produces 200lbs in lift a 60mph. The lift is four times stronger at double
the speed. This would be 800lbs at
120mph. Our cars are similarly shaped
and bigger. Interpolate this data as
you wish.
From Eschew obfuscation:
'92-97 Crown Vics = 0.34 Cd, 25.5 ft^2
frontal area
'98+ Crown Vics = 0.36 Cd, 26.3 ft^2 frontal area
Note to the Police: I have heard several times that the reason Ford uses a smaller
rear swaybar on a Police Interceptor is because the rear springs are
stiffer. Maybe. I think it is because the Interceptor is
programmed to run a top speed of 129mph.
Your back end will be getting light and the car dangerous to control in
turns. If you read this manual and
balance the car for 60mph, you will pay hell for it at top speed if you try to
turn the car. You just may need a giant
ricer wing to keep your butt planted in a high speed turn. Brake bias modifications may also get you in
big trouble. Bottom line, doing the
modifications listed here could get you killed at high speeds. Anyone else doing these speeds on public
roads, please do all the modifications listed here to help remove your gene
pool from future traffic.
Brakes:
Sports
cars are known for their braking power.
This is part of handling. In
Fords wisdom they conceived that if the rear brakes lock first, your car may spin
and this is true and dangerous. So to
make double sure this would never happen, they shifted the brake bias toward
the front so the rear does very little.
Yes, for this safety benefit, you loose the first objective, which is to
be able to stop the car. So how do you
fix it. I did my front brakes first
with HD Severe Duty Raybestos SSD748 brake pads. These are a harder compound to help with fading. A harder compound has a lower coefficient of
friction. That is a fancy way of saying
they do not work as well but they do not fade as much either. The rear brakes were left stock. I knew the brake bias was to strong on the
front, but WOW at the new braking power!
Much better! The good part was
the rear never tried to lock up including in the rain. Then I decided to try using them going hard
into a turn. I almost stained my pants
and the car's seat. The car went
sideways about 15 to 20 degrees like it was going into a spin. Each day I normally have a shot at this 180
degree turn with out traffic and it is one lane so I do not have to worry about
on coming traffic. Each day I noticed
it would do the same thing but the tires never slid. The rear tire slip angle was massive, but the tire contact patch
was hooked up. It is a bit unnerving,
but has always been safe. At the second
Auto-X this year, I tried out the new brakes.
As I approached every turn I did my best to hold off, but the brakes
were so fast and strong, I tended to over brake. What a change from the first AutoX. Most real sports cars do not have this sort of braking
power. On the race course I could push
the car even harder and she will start to turn sideways, but it was always easy
to control. At the first AutoX, the
brakes were weaker, but she never tried to turn sideways. However she locked up on one turn and shot
straight off the course blowing my best run.
I would NEVER want that to happen on the road! I have never had that happen before, so it was a rude
awakening. With a car trying to spin
you can counter steer and keep on the brakes.
When the front brakes locked, she went dead straight. Had there been a guardrail, pedestrians, or
another car, I would have creamed them.
Obviously I am happy with the change in brake bias. But then I am very comfortable with going
sideways. If you are not, then don't
mess with the bias!
Quite
often a brake proportioning valve is used.
Most of the time this is done on cars with front disk and rear
drums. Our non ABS equipped cars have
one mounted to the master cylinder. It
is the aluminum hex device on the brake line going to the rear. I have seen adjustable proportioning valves
for as little as $38. Such a valve can
easily adjust the brake bias. It would
be nice to jerk the stock unit out and replace it, but Ford used a very odd
thread and o-ring to seal the joint between the valve and master cylinder. My plans are to disable the stock unit and
add the adjustable unit. One member
here, lifespeed, has done this modification with an adapter to replace the
stock unit. He was pleased with the
increase in braking power. Good work
lifespeed!
My
parts man researched the panther platform and noted that all our cars use the
same size rear pistons. I would
consider playing with rear calipers to be a 99% closed door.
Many
of us are switching to 98+ front brakes.
Why? Pre 98 brakes have a nasty habit of warping and causing
vibration problems with the brakes on.
People who tow heavy loads should also consider updating the brakes. 
This
picture says it all. There is one catch
... you will need 16" wheels to mount these big boys and yes, the 98+
brakes are on the right. The 98+ brakes
will spell the end of warped rotors that has plagued pre 98 CV/GM cars. If your rotors are not warping every 10k or
whatever, then don't worry about it. If
you plan to tow heavy loads with a pre 98 CV/GM, then I would think hard about
upgrading. Please see the “Technical”
section at www.crownvic.net for details
on the conversion. Great work guys!
If
you are skidding, then the world’s biggest brakes will not help. Only better tires will help. If you are fading your brakes or heat is
damaging them, then larger brakes can help.
Other wise, don't waist your money.
If your brakes can not easily lock the tires, then you have a brake
problem that needs to be fixed. All
CV/GM cars have a light brake pedal that can easily lock the tires. Brakes larger than you need are nothing more
than lead on your wheels and that hurts the ride and handling. No one would use his or her hard earned
money to do that. If they work don't
fix them.
If
you do work your brakes hard and that includes towing, note this. Brake fluid absorbs about 5% water a
year. Water lowers the boiling point,
rust parts, and cost $$$$ on ABS systems.
Change it out yearly. You never
want it to start boiling. You will
loose your brakes completely! Bleed your brakes yearly and you will not have
any problems. This goes triple for ABS.
DOT
3 fluid is recommended by Ford and does fine for most any driving. DOT 4 is compatible and has a higher boiling
point. DOT 5.0 is silicon based and
makes the brakes spongy and is not recomended.
DOT 5.1 is glycol base like DOT 3 & 4. It has an even higher boiling point, cost a lot more, and is hard
to find.
With
ABS, never push the pistons in with the bleeder valve closed. This will force the old fluid into the very
expensive ABS parts. The odds of having
ABS problems in the future approach 100%.
Braided
stainless steel brake lines expand less with pressure. As a driver you may notice that the brake
pedal is firmer. Many people like this
and feel it was worth the money.
Acceleration:
Sports
cars are supposed to corner, brake, and accelerate on command and in any
combination. Talking about the engine
would be outside the parameters of handling.
Also there are much better experts on getting HP out of a Ford 4.6 SOHC
engine than me. However, getting that hp to the ground coming out of a turn is. If you try to solve the problem with super
sticky tires, it backfires on you. With
super sticky tires you can now corner harder.
That just takes the weight off the inside wheel faster than what the
sticky tires can make up for. Anything
you can do to shift weight over the drive wheels will help. Anything you can do
to reduce weight shift from the inside tires to the outside tires will
help. Anything you can do to reduce
understeer without resorting to a large rear swaybar will help. However a
limited slip differential is the only real solution. Drag racers have other differentials that work best for
them. Road racers handle best with
limited slip differentials. Just accept
the fact that the clutches wear and need to be rebuilt every whatever or so
some people say and I am in no position to question wear rates.
The
Ford limited slip works fine. The
preload on the clutch pack can be adjusted by adding plates or with different
springs. They can be found for about
$100.
Auburn
makes a good unit too. They run about
$270 and up. Torsen makes a great unit
too.
An
open differential will not let you accelerate hard out of a turn. Just tire smoke.
|
Driver ergonomics: Taking
care of the driver helps reduce track times and makes for fewer
mistakes. If half your brain and half
your body muscles are being used trying to stay in the seat, it WILL hurt
cornering power and driving. It takes
skill and concentration to hold a car at the limit without going over. There are two key parts to help. One is a
good seat with good lateral support.
The best is a good full harness. Together a seat and |
Rocket Couch shows us how
it's done
|
harness
securely hold a driver put. Safety is
also greatly enhanced. Installation of
a seat is not that difficult. Proper
installation of a harness is. The lap
belt is fairly straightforward. But
without a roll cage there is very little left to tie the shoulder straps
to. With a stock sedan, the only way I
have seen is to run the shoulder harness to the rear seat belt bolts. This long distance may exceed the belt's
length. You may need a manufacturer who
is willing to work with you and add some extra footage. A FAA crash inspector told me that a dual
shoulder harness cuts your chances of death in half. This is in flimsy planes that do not even match a Yogo. I would only expect better in our cars. If you are extra long waisted, your
shoulders may extend past the top of the stock seat. This will cause the harness to push down on your shoulders
increasing the chance of spinal compression injuries in a wreck. I would highly recommend a race type seat
with shoulder strap slots to prevent this.
Many of these seats have nice upholstery that will blend in better.
Be warned: Some people have had problems with the Police claiming the race
harnesses are not DOT approved. I know
this has got to be the stupidest thing I have ever heard, but be warned. I figure it is my life on the line, so screw
the law. There is not a racing
association in the world that would allow a pathetic DOT harness in a real race
car because they are not nearly as dependable, secure, strong, safe, and spread the loads out as well.
Boxed Control Arms
This
is my opinion, but I believe unlike red "R" stickers, boxing the arms
will HURT the handling.
"I"
beams, round tubes, square tubes, channel, angle, bar, or whatever shape has
nearly identical tension strength.
During compression, round tube is the strongest, but equal till the
other shapes buckle. Failure is from
buckling when compressed. I have yet to
see this happen on our cars. The
compression of the metal during hard driving would need to be measured with a
caliper and would be in the thousands of an inch. This would be nothing compared to the rubber mounts. The main difference in all these shapes of
steel is in torsion. The stock arms are
horrible in torsion. Tube again is the
strongest. Boxing the arms will
dramatically improve the torsion strength of the control arm. So what?
The stress is in pushing and pulling on the arm. Precision steering is from keeping the arms
from elongating or compressing. The
control arms only purpose is to locate the rear axle. Most race cars use rodends.
With these you can twist the control arms with your hands. Stock control arms are already very rigid
for this work. The stock rubber
bushings are the source of 99% of the flexing.
To fix the problem, many people use polyurethane bushings. This works.
The play is in the rubber and not the control arms. Once you use polyurethane, the joint becomes
very rigid. Not just standing up to the
push/pull forces, but in twisting too.
Polyurethane is not a ball joint or rod end. If your suspension is to twist or move, there must be some give
somewhere. Pre 98 cars have non
parallel control arms so there is twisting even when the suspension is going up
and down. If you remove the flex in the
joints and box the control arms, there is nothing left. This is called binding. When your +4000lb car leans hard into a
turn, the suspension must lean some twisting the suspension. With this much weight, it will lean. This will put lots of stress on the control
arms, frame mounts, and wear on the bushings.
Something very likely will break one day. Mean while your car will handle worse because the suspension is
binding. You want every joint in your
suspension to move effortlessly and very smoothly. Friction free movement improves ride and handling. The tires will follow every contour of the
road better. Binding in the rear will
act like a swaybar. The stock stamped
semi channel shape is strong enough for all normal loads. In torsion it is very weak and will twist
with little effort. Once you remove the
soft rubber, the control arms are all that is left. Let them twist. It is
ok. Just fix the soft rubber if you
want a more precise handling CV/GM.
Just look at what the "Watts Link" did for the 98+ cars.
Some people say their cars
handle better with the boxed arms and polyurethane. So how do you explain this? Well
it is like this. The polyurethane does
help locate the rear axle much more precisely.
The boxed arms bind the suspension, but the +4000lbs still finds a way
to twist something. This will act much
like a swaybar. Addco has proven that
the 70% increase in the rear roll stiffness Vs the fronts 40% will make our
cars handle better. The increased roll
stiffness from boxing the control arms will balance a stock CV/GM for better
handling. But for how long. Welds are brittle. Don't let any welder tell you otherwise. You do not want to flex the welds. Till someone can show me years of endurance
testing to prove this will not break from a fatigue crack, then I will stand
against boxing the arms and recommend swaybars that are designed to hold the
weight of +4000lbs in a turn. Also
polyurethane is not a roller bearing.
It does have friction. As the
loads go up, the friction goes up. The
binding loads in addition to the normal loads only makes it worse.
If
you are drag racing and have hp and traction sufficient to buckle a control
arm, then box away for drag racing only.
Warning: On 98+ cars there have been some failures with the
rear control arms and frame mounts.
This is with stock cars. If you
drive hard and do modifications that increase the loads, then reinforcements
may be necessary. Ford has come up with
a reinforcement kit. It does require
welding.
Cadillac Ride
At the beginning of this to
long article, you said the balance of ride and handling is up to the
owner. All you have done is shown me
how to make my car ride like a truck.
How do I make it even smoother? Buy fiberglass belted tires. Have the tires/wheels high speed balanced on
the vehicle. Go to a custom stereo shop
and have them add sound deadening insulation everywhere. Spray expanding foam in every empty
space. Do not buy a HHP packaged
CV/GM. Do buy a 98 or newer
vehicle. Buy a vehicle with air rear
suspension. Want more? Buy a Cadillac. Sorry to be short, but this is not my normal direction to make
modifications.
Summation:
Don't
get mad for putting this last after making you reading the long path. If you want to make your CV/GM handle, here
is the top 4 with a tie for 3rd list:
1. Buy the best tires you can.
2. For more cornering power and steering
response, buy the widest rim approved for your tires. This may mean dropping the tire width you wanted so they fit.
3
& 4. Nothing makes twisty roads
more fun in our land yachts than Addco swaybars and Bilstein HD shocks.
These
4 upgrades will make large improvements.
From there the gains get smaller.
Listed in no order:
*
Lower the car.
*
Reduce the brake bias to the front brakes.
*
Upgrade to 98+ brakes if needed.
*
Add better seats and a harness.
*
Start shifting weight to the rear and dropping the weight lower.
*
For pre98s, replace "A" arm bushings with Energy Systems. We are still waiting for 98+ bushings to be
made.
*
Titanium nuts and bolts only cost $100.00 to $200.00 per pound of savings. LOL!!
What CV/GM cars handle the
best?
Pre
92 CV/GM cars are referred to as "Box Cars". As far a stock car goes, they start at the
bottom. They tend to have problems
holding alignment and tend to have the worst tire wear.
In
92 Ford did a major redesign. The front
control arms/bushings were re-engineered for better performance, improved ability
to hold alignment, and better tire wear.
In
97 the steering gear box was redesigned for much tighter steering.
In
98 Ford did some fairly major revisions.
The rear suspension was changed over to a parallel four bar system with
a "Watts Link". This got rid
of most of the tail wagging. The front
"A" arms/bushings were redesigned again. Once again the handling and tire wear was improved. The wheels were enlarged from 15" to
16". A lower profile tire was used
to keep the diameter nearly the same. This
gave room for some larger brake rotors.
The front calipers were changed from a single piston to a double
piston. This appears to be the end of
warped rotors that plagued previous models.
The cars appear to be a little lower.
In
2001, Ford came out with the SAP model CV.
The wheels are +sized 1" with 2mm more offset. New PI heads up the HP about a dozen.
In
2003, Mercury's new Marauder will have some major re-engineering. The engine will have 302hp, 318ft/lb of
torque and four valves per cylinder.
The wheels will be 18x8 with a totally different offset. The front control arms appear to be cast
aluminum. The front cross over beam is
aluminum. A rack and pinion steering
system will take over directional control.
The rear shocks will move to the outside of the frame. Most likely just to help keep the gas tank
from exploding. The rear rotors are
ventilated. The shocks, swaybars, and
springs are revised. A test drive
showed that handling is way up, and the ride is as good as ever. Power is up some but dropping from 8.0 to
7.5 seconds in 0-60 is not a big leap.
Adding nearly 200lbs offset some of the power gains. The car is quieter with the exception of the
exhaust and more solid than ever. The
exhaust note is up, but very pleasant and not there during cruise. One word ... "NICE"!
It
just keeps getting better. Thanks Ford!
Safety:
Many
of us bought our cars for a large cars safety record. Statistics show that when a small and large car connect resulting
in a fatality, it is 13:1 on being in the small car. That is with a tendency
for young people to drive small cars and older people, large cars. If you are reading this article, it most
likely means you tend to be aggressive. Lol!
For whatever the reason, the rest of this section will be on how to make
your car safer.
Number
1 is the driver. Racecar drivers and
Police have a worse than average accident rate. So much for skills. The
math spells it all out. Experts show
our cars stopping from 60mph in 143' and from 70mph in 186'. That small 10mph increase in speed cost even
the best drivers 43'. Feet means
nothing. That last 43' equals about
25-30mph! That is no mild hit. Pure physics keep expert drivers from out
doing Joe Average out there. Lots of
people are athletes pushing reflexes to the limit. It may be tennis, pin pong, basketball or whatever. And we all practice an hour or two a day
driving. Throw in ABS and the worst and
best drivers stop nearly the same. Just mash the pedal. Impact energy is expediential. Upping your
speed from 45mph to 60mph is only a running speed of 15mph. Energy wise things just doubled!! That means your neck, spine, seat belts,
seats, crush zones, and such will have to withstand twice the
force/weight/energy or whatever you want to call it. Bottom line … control your speed, control your ego, and control
your driving. Driving skills have never
changed God’s law of physics and never will.
Physics will also win every time.
Keep racing on the track and you/others will live another day. The same applies to Police in high speed
chasses. I have lots of trophies from
dirt bike racing, car racing, and flying.
Still I have never and will never break God’s laws of physics. My orthopedic doctors have documented every
case that I tried.
To be
continued when time allows.
X Racer's Performance
Philosophy:
If
you want your car to perform, you must have an attack plan. Most everyone has a budget. Most everyone is limited on time. There forth, you must be looking for the
most improvement for the buck and time or effort. The formula is Time + $ = S.
What is S? Speed or whatever you
want the car to do. If it is 1/4 mile,
it is ETA and reaction time. If it is
AutoX, then it is a stop watch or timing system. A performance graph is exponential. That means that you get a lot for your money to begin with. Eventually you can keep spending money with
no real increase.
Here
is a good example. Discounting results
with CV cars, KYB shocks give a lot of bang for the buck. Koni is known for being a better shock. Everyone tends to believe that. However, I can easily say that KYB is a
faster shock and prove it using the above formula. Most would agree that KYB gives about 90% of the performance that
Koni gives. Koni is just better. However, KYB cost about 30% of what Koni
cost. You have to spend three times
more to get 10% more performance. This
would put Koni shocks on the steep part of the curve. That means lots of money with little result. 90% of the budgets could not get that high
on the curve. If you take the savings
from using KYB shocks, you would have money to continue doing modifications on
the less steep part of the curve. These
too would give more bang for the buck.
The person that bought Koni shocks would have used up his/her budget too
fast and not be able to do additional modifications.
Most
every car enthusiast knows how to make a car faster. Give them time and they could write an article just like this
one. Asking them to graph out the
performance improvement Vs cost and time would leave most scratching their
heads. I believe using this philosophy
is what separates the losers from the winners if everything else is even. Even being budget and drivers skill.
One
last example: Everyone knows that
lightweight forged rims are fast due to weight reduction, improved sprung to
unsprung ratios, and lower rotating inertia.
However if poor Billy Bob takes his steel rims in for being cut and
widened at a cost of about $25 a piece, he would get the biggest bang for the
buck. That is the great performance of
wide rims. The rest is an improvement,
but for the money and the small performance gain, they are a big looser! A stop watch at an AutoX would show a much
bigger gain with the rim width even though it is heavier and tends to flex
more. Lightweight forged aluminum rims
would eat up a budget very fast. Again
bang for the buck and time.
To
sum up everything here. You can take
all my BS about scrub, polar movement, Time + $ = S, and everything else, and
throw it in the trashcan. The bottom
line for anyone driving on the street is how the car feels when you grab the
steering wheel, hit the throttle, and hit the brakes. These three controls are the bottom line for everything and you
are the final judge. A 1st place trophy
at an AutoX is the final judge there.
Same at the drag strip. For most
of us, it is the smile on the face on some winding mountain road or a favorite
turn on the way to work. All the BS
here is just to help you max out that smile on a windy road as I have yet to
hear of someone who bought a CV/GM for serious racing. There are many many better handling
cars. Just not with 6 seats and 20
cubic feet of trunk space. Lol!
Disclaimer, Risk,
and Safety notes:
Our cars are more powerful and lethal than the world's most powerful
handguns or rifles. Yet here we are
talking about modifications to its guidance systems. One mistake and it could be the end of you, your passengers, and
any other person(s) who happens to be in your missiles way of harm. These are moderated speed and high mass
projectiles that kill 40,000+ people a year.
They maim many times more leaving them in wheel chairs or worse. Our roads are not racetracks, nor are our
driver and mechanical skills infallible.
All it takes is a tire cut on a fender lip at the wrong turn, or a ball
joint that decides your harsh driving, the super sticky tires, and/or whatever
is too much and you become a statistic.
I could even type an error here.
YOU are the only one responsible for taking action on anything
written here and for verifying its safety.
I am not an engineer and I do not guaranty any car, much less our
CV/GMs, can withstand the additional stresses imposed by any of these
modifications. Already several of us
have snapped the endlinks used to mount the swaybars because the nuts were over
tightened. Popping a swaybar mount at
the wrong time can cause massive oversteer or understeer at the wrong time
and/or place. I have failed a
"C" clamp to the swaybar in the middle of a turn. I was lucky. When YOU modify YOUR car, YOU are reengineering it with stresses
that could fail a component quickly or it may take years for the stress to show
its potentially lethal blow. This is
called a fatigue crack. You may not get
a warning. A fatigue crack on a front
axle put me in my first wheel chair.
No one on any of these forums including myself has the slightest
idea how much safety margin Ford built into these cars. NON!
No one here has the slightest idea what sort of quality control and
safety margins are built into the after market parts listed here. I have never even visited the
factories. I have had many after market
components fail and many more never made it to my car, but instead were placed
in the trash can for permanent storage.
Many other products needed modifications to work. Not only does no one including myself have
any of the above knowledge, but we are totally dumb as to who is reading this,
what sort of driving skills you have, much less knowing if you know which end
of a screw driver to use. Do understand
this!! Every modification listed here
DOES REDUCE the SAFETY margins Ford built into them. This includes not just mechanical systems, but also your ability
to safely drive the car. A well
balanced car is just like a balance beam.
It will not take much to send you over the wrong way. This simply means it may be easier for you
to loose control. Most cars are not
well balanced and so most drivers are not used to such. It takes greater driving skills, reflexes,
knowledge, and more to even consider the listed modifications, much less
implementing them.
Please note that there are no instructions here on how to perform
any of the listed modifications. Your
car springs have more energy than a 44 magnum gun. Messing with them can kill you!
This is not a manual for doing the modifications. It just lists general handling expectations
from modifications. We highly
recommend you hire an expert if you have any doubts as to the actual mechanical
work and/or your skills in performing the work. Even when hiring pros, note that the swaybar endlink failures
were because of the hired professional mechanics and/or because Addco forgot to
add the instruction list. Obviously
Murphy's (As in Murphy's Law) list of things that can go wrong is endless. I will not list them for you. Use your own imagination, as it is nearly
unlimited.
Obviously, we have never and will never test every combination of
possible modifications. Handling is
part science and part art. There may be
some combination of modifications that can be disastrous to safety and
handling.
If you hurt yourself and/or others and try to sue me because I am
nice enough to share the CV/GM fourm's knowledge and my knowledge with you, you
need to know the following.
1. I do not have much money.
2. What I do have is for my
wife, my daughter, and our retirement when my wife and I are too old to work.
3. If you try to sue me for what
you read here, I will consider you to be the same as a thief with a lawyer as a
weapon in the lawless land that we live.
I will protect my family as if you were a bandit, whom you are if you
try to take our money, home, retirement, wages, or anything else. I do not plan to work till I die, so you
can have my hard earned money. I would
rather die and guess who dies first.
This is the only guaranty I give.
As long as my heart beats, this guaranty is valid!
4. If you want to sue, go to
Wallmart. They are the #1 company to
sue with about 6 trials a day and 6000 open cases. Wallmart uses lawyers and I use 9mm++.
5. If you must contact me
over YOUR mishap, I will gladly give you my personal list of good orthopedic
doctors who put me back together.
6. YOU are responsible for
what YOU do to YOUR car!
More
from the Internet!
Must See Video! Awesome shots showing DOT race tires at
their max.
Click
on the very bottom right video. Watch
how the tire moves almost covering up the rim.
Also notice how much suspension travel is used in the turns, braking and
acceleration. This film clearly shows
how much tires move around affecting suspension clearance. Don't just look at the tire distortion on
the pavement. Look at how the tire
moves sideways even at the top! This is
why we have to add more clearance than what we see while parked. Narrow rims and wide tires just make it
worse. Remember this is the rear wheel on a front wheel drive car. The fronts work much harder on these
cars. Our rear tires work much harder
than theirs. 4,000+lbs does not help
either.
[Sorry – the link
turned into a porn site!! – SS]
This
site has some ok video on slip angles and contact patches
http://www.microsoft.com/games/precisionracing/cart/racingschool1.htm
This video shows just how
quick and easy it is to loose it and hurt people. It
is bad enough this happened on the track, but it means jail time, civil suits,
and more if done on the street and rightly so.
It is graphic. The video was
taken at an Auto X. These races are run
at the same speeds you drive on the road.
http://www.z06vette.com/media/idiot.mpeg
Links:
Energy
Suspension - Swaybar bushings, control arm bushings, and more
http://www.energysuspension.com/index.html
Bilstein
Shocks
Koni
Shocks
Tire
Rack
http://www.tirerack.com/index.jsp
Police
tire test ... skid pad, braking, slalom, and high speed for both wet and dry.
http://www.nlectc.org/pdffiles/TireReport1999.pdf
Police
brake pad test
http://www.nlectc.org/pdffiles/brakepads_epr2000.pdf
Suspension Links:
Suspension:
http://www.rqriley.com/suspensn.html
Materials:
Gear
Ratio Calculator - 5 gears, tire size, ring & pinion, rpm
http://www.primenet.com/~jraitter/gear.html
Speed,
Gearing, RPM, Tire Size - Calculator:
http://www.angelfire.com/fl/procrastination/rear.html
Turbocharger,
ET, MPH, etc ... Calculator:
http://www.turbofast.com.au/javacalc.html
Everything
http://www.bgsoflex.com/auto.html
Ruth
Wolf talks about tires and slip angles
http://thunval.com/racing/trailer/tech_series/tech1.htm
Ruth
Wolf talks about the Friction Circle
http://thundervalleyracing.com/features/tech/wolffriction.html
Cool
tire tech for Hoosier Tires
http://www.rsracing.com/tech-tire.htm
E mail a link, data, or anything else that you think would add to
this article.
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