PI questions...please help

[Mr. Stallion]

I just recently did a full PI headswap on my 98gt(heads/cam/intake). I went through a few bumps getting everything going....mostly with trying to get the fan & temp gauge sensor to work right because the PI intake only has a place for the temp gauge sensor to go. Anyway, I figured it out and now the cars runs perfectly. I used 00' parts for the swap and I'ved talked to others on different websites and they all tell me that this mod is a huge difference and i'll notice it as soon as I get on it. Well I did that.....and it doesn't really seem to be that big of a deal. I've had all types of theories as to why I feel i'm not getting the power I want.

1. Maybe I need to have it tuned
2. Maybe because it's a convertable it's just waay to damn heavy
3. Maybe the parts were faulty??

I have everything checked before I put it on(took to a machine shop) and all checked out ok. Before the swap I basically had a bone stock 98gt with the only mods being cold-air & off road h-pipe.
During the swap I added a ported upper intake, bbk pullies, & JBA headers.
Now.....I would think that after these mods along with a full PI swap it would feel like a totally different car. I'm not too impressed as of yet though.....and a lil upset....especially after all the money i've spent and the time it took to do the job. Now i've done everything by the book with the installation....the timing was done correctly and the chains were set perfect. The cars runs perfect and everything is in the right order......it just doesn't seem to have the power I thought it would.
I am going to dyno it, and i'm afraid that the numbers will be very poor comared to others who've done this job and have good things to say. Most whom i've seen do this job get around 270rwhp and about 306rwtq. If I can just get that i'll be happy.

My question is......for all you who know about the PI swap...either had it done or have just done the work on someone's car.....it is supposed to be a big differnce over stock right??? Is there something that I didn't do??? Is a tune neccessary??? with all the mods i've done I just hope that everything is ok and that i'm just expecting too much.
With all i've said(sorry for so much) is there anything I should check on? Maybe see if there was something I missed.....any other PI guys that can help?

 

[white_pony]

What heads did you get? I just got mine done, and I noticed a huge difference, could be since I also went with a stage 2 cam to go with it.

 

[slvrbullIT]

yep, just wait until you go to the dyno and you will know for sure. remember that stock 96-98 gts dyno around 190-195rwhp and 270rwtq. i could tell a difference right when i got it done but i didnt know exactly how much i gained. i then got my car dynoed at 252rwhp/290rwtq(stock pi heads) which i think is pretty good for the mods i have. i dont have my car tuned yet either but from what ive heard, with a tune my car would be around 260+rwhp/300+rwtq. it also depends on what have been done to the heads like porting and polishing. good luck with it.

 

[billyfe390]

Well the first thing you will notice is the fact that it will actually rev all the way to 6k instead of dying at 5k.

 

[LI98GTStang]

Very curious as I believe you should feel something with not only the heads/cams/intake, but with the increased compression, the pulleys and headers also. First things first. Just to be sure (and to point 3), you do have PI heads and cams right? You say they are from a 2k car, but did it say PI in the castings? Verification?

Is your car an auto? That might explain something since most of the gains are up top and if your car is shifting before the peak hp, that might be something.

 

[Mr. Stallion]

Very curious as I believe you should feel something with not only the heads/cams/intake, but with the increased compression, the pulleys and headers also. First things first. Just to be sure (and to point 3), you do have PI heads and cams right? You say they are from a 2k car, but did it say PI in the castings? Verification?

Is your car an auto? That might explain something since most of the gains are up top and if your car is shifting before the peak hp, that might be something.

I know for a fact that the heads and cams are from a 00' motor. The PI numbers were clearly marked on the heads when I purchased them, I also did a comparison with my stock non-PI heads. They are PI's for sure.
Did any of you guys add a set of headers while you did the swap??? Did you have to go with an exhaust for 99+?? I put back on my bbk off road that was on my stock 98, but it has a weird fit.
Anyway I guess i'll have to get a tune first then. Would it be safe to run nitrous on the motor for an upcoming track day? The only place I can get a good tune is fully booked and my track day will be here before I can get a tune. I was only going for a 100 dry shot...maybe 4-5 runs

slvrbullIT: you got 252rwhp 290rwtq??? Untuned? What mods did you have during this dyno??

 

[slvrbullIT]

Mr.Stallion:

Actually the first time I got my car dynoed was without my timing adjuster and I dynoed at 240rwhp/277 rwtq. Then I put my timing adjuster on and went back to the dyno a week later and dynoed 252rwhp/290rwtq. This dyno was with all the mods in my sig and no tune. If you dont have a timing adjuster you should get one, it helped me out alot.