Originally Posted by willwren
With no other mods to support the flow, that'* probably true, but the guys putting on headers have much smaller pulleys on the superchargers, and usually rockers or a cam.
Well, no, not really. Yes, with a smaller pulley the torque gains will be larger, as with a cam and rockers, but on a stock GTP with just headers it gained 16hp & 18ft.lbs at the wheels. No pulley change or anything...just the headers. Thrasher used to have the dyno sheet and everything from it up on their site, but they have since re-designed the site and now it says up to 25hp gain on a stock car. Heres a link: http://www.thrashercharged.com/store...t_headers.shtm
Headers AND a smaller pulley will make an even larger difference.
On an N/A 3.8 though, I am pretty sure you lose torque.
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!