Did a little reading in the Archives, and came up with some interesting numbers:

Comparing a '99 P71 to an '01 P71, I am aware that the 2001 is rated at 235 HP, vs. 215 HP in the '99. According to the figures I found, a '04 or '05 PI intake would be good for about 15 HP on the ground, on the '99. PI cams, according to these numbers, would be good for about 15 more HP on the ground on the same '99. I figure that's about 35 HP at the crank, right? That would put a '99 Model with PI cams and intake (with NPI heads) at around 250 HP with nothing else done, yet the '01, with an intake that's probably good for about 5 HP less and the same PI cams is rated at 235 HP. And supposedly, that includes about 5 HP for the PI heads. If these numbers are right, how can the '99 turn about 250 at the crank with NPI heads when the '01 turns 235 with PI heads? I'm not figuring anything for HP gain from added compression, since the PI heads would be on the PI engine.

Are these numbers right? Can I take a '99 P71, add a PI intake for a '04 or '05 plus PI cams, and end up with around 250 HP at the crank? If so, that makes the '99 even more attractive over the '01, since with the '99, I would get 3.55 gears, AND a stinking TC drain plug, which is significant to me.

I'm thinking seriously about upgrading to a '99 if these numbers are good. I would think in this case that with the MM airbox/MAF, zip tube and tuner, plus a set of underdrives perhaps, I should be somewhere around 260 HP. That's the number I'm really looking for, even tho it probably still wouldn't have the torque of an LT1 350. But geared 3.55 versus 3.10 (I believe, for the 9C1), I might just be able to keep up, and stay in a P71. That's the plan anyway.

Thanks for any input you can share.

Most of these upgrades produce significantly less hp than claimed. Also, you are making the mistake of believing Ford's hp claims for stock.

If you want performance then you want the PI heads.

a friend of mine did the PI intake and cams on his 97 GT. stock NPI heads. he said his dyno test showed a 26 rwhp increase even with the temp and humidity being a little higher than it was on his baseline runs. obviously im just going at his word, i wasnt there with him. i can say that i noticed his car had plenty more pull next time i rode in it.

The gains from PI cams ALONE are not all that great, maybe 10-15 RWHP. If you add the PI intake that nearly doubles, if you bump the shift points and rev-limiter to around 6,000 RPM, you can gain nealry 35 RWHP over the stock NPI set up (peak to peak at 6,000 rpm). This is because the NPI stuff drops power off FAST over 5400rpm, so the differences at 6000 rpm or ore are very significant.

So, the answer is: It depends.

Thanks, John. Even if it's just 10 RWHP, if you figure another 15 RWHP for the '04 P71 intake as previously stated, that still comes out to about 29.... so let's round off to 30... HP at the crank. Right? That would put a 215 HP otherwise stock '99 P71 at 245 HP WITHOUT the PI heads the 235 HP '01 would include. I still don't understand how it can work out that way, but it looks like one would actually be better off in terms of power going this way. Plus, you get 3.55 gears, a TC drain plug, and about a thousand dollar lower price tag.

I'm leaning strongly towards upgrading to a '99 and starting with these two mods, plus Time Serts or another spark plug thread remedy while I have everything torn all apart.

That sounds like a damn good plan, good luck with the project!

My dear friend Charlie:

I am aware this has been done before. Well aware. I also used the 'search' function. I posed a question based on things I learned while searching that contradicted each other. And I appreciate the constructive answers I received.

If I had a choice between a 2001-up Panther and a 98-00 Panther, I'd take the 01-up Panther and modify that. But if I had a choice between a Ford and a German diesel, I'd take the German diesel.

Metro:

Thanks for your response.

I noticed you mentioned that same preference on your FAQ site. But since you get a TC drain plug and 3.55s on the '99, plus about 30 more HP if you do the intake and cams, I am really curious as to why you still prefer the '01 or '02, with 3.27 gears and no drain plug. I can certainly afford an '01. That's not the problem. It just looks to me like an upgraded '99 would be more car, for a little less money. Looks like about 245 HP on an upgraded '99, versus a factory rating of 235 HP on a stock '01. Which may or may not be totally accurate.

I'm going to make this move in the near future, and would appreciate any input.

Virginamountainman - ask yourself this:

Why would a NPI head car make better power than a PI car when the only (major) differences apart from the heads are that the NPI car has a more recent air intake? This would suggest that the air intake is worth more than the PI heads which seems most unlikley to me!

How about if you added the intake to the PI car?

Something is wrong in the math here.

Incidentally, if there is any way you can afford it get an 03 - the suspension & brake changes transform the car.

One Q - by "air intake" I assume that you mean the "zip tube" - if that is so then you need a larger MAF since the zip tube is for an 80mm MAF (or some sort of adaptor).

A base NPI eninge with PI bolt-ons (cams/intake) will never out power an "all PI" engine.

HOWEVER, ported NPI heads with the SAME cams and intake as a full "PI" engine w/ported heads will make more power. Not a lot more, but more.

MAFs, zip-tubes, and air boxes are all addative, but not in the traditional 1+1=2 way, more like the shortest distance between any two points on the globe is NOT a straight line on a flat (2D) map, but a curved one.

Yeah, I had the embarrassment of riding in a new 84 VW Rabbit diesel that did all of 40MPH top speed up big hills. I was about 12 years old at the time. My dad must have been embarrassed too as he sold that diesel Rabbit and bought a new Porsche the next year.