Originally Posted by Rogue
So it pulled 334 before, 335 this time with exhaust and 340 after dropping the exaust?
Yes. I also think its kinda funny that people feel they need 3" exhausts on their cars when the GTP at that power level only picked up 5whp from dropping the 2.25"
Its kinda wierd though. No matter what we did with fuel or timing it didn't make any less/more power. With 2 degrees added timing and 8 degrees added timing it pulled the same amount. With 890 02'* and 980 02'* it still pulled the same numbers. Not quite sure what would cause that, it doesn't make a lot of sense to me. But it looks like ~340whp is about the limit of what can be done with stock heads and a Gen 3 M90. Looking at the dyno numbers on club gp there are a suprising number of people in the 325-340whp range with Gen 3 & stock heads, it looks like not much more than that can be done. Even with a Gen V and stock heads nobody has even hit 350 IIRC. So it looks like to go any further the car needs a bigger power adder (turbo, whipple, M112, etc...) and/or different heads.
Not quite what I was expecting, but respectable numbers no doubt. And, realistically the only difference between the car now and when it pulled 315.6whp is the XP cam. We didn't really do much else to the car besides little stuff here and there to make things work better and whatnot. So basically the car picked up 25whp going from stock cam & 1.9 rockers to an XP cam. Thats over 31 crank hp. Imagine what the gains would've been if it were stock rockers & stock cam to XP cam.
1990 Maroon Grand Prix STE McLaren 3.1 Intercooled Turbo, 14.695 @ 94.49 on 12psi before cam/heads/etc.
1990 Bright Red Grand Prix McLaren 3.1 Intercooled Turbo, 14.819 @ 92.72, 189whp
1999 Grand Prix GT 9.75:1|K&N|160 tstat|No Ubend/Cat/Res|UD Pulleys|Ported M90/TB/Heads|XPZ|2.55"|Pacesetters|Stage 2 I/C. 12.442 @ 112.78
2000 Blue Bonneville SSEi Supercharged Gutted Airbox|K&N|3.4"|1.9'*|WP Pulley|Custom DHP|180*stat|41932'*|No Cat. 14.681 @ 94.80
2002 Dark Cherry Grand Prix GTP Supercharged & Intercooled
12.084 @ 114.38 w/1.743 60', 315.6whp, Fastest Stock Cam M90 GTP!
NOW XP CAMMED, 340.6whp with XP, stock heads, Gen 3 M90, 11.984 @ 115.84 w/1.750 60'!
Most HP Stock Heads Gen 3 M90 GTP!
2004 Red Monte SS Supercharged K&N|3.4 Pulley|1.9'*|180*stat|41919 plugs|3" dp|No cat/ubend|DHP|Shift Kit. 14.2 @ 98
GOT BOOST??? Friends dont let friends drive stock!