Originally Posted by fantastic88
I found the cats for the 3.8s. Just have to measure the exaust to see if i'm 2.25 or 2.5. I just hope this flows good enough so nothing in the engine gets stressed. One more question. I won't be running a DHP for a while. How do stock PCMs react with rockers?
Stock PCM'* react fine to rockers. You won't get an SES light or anything like that, its nothing to worry about, but when you get a DHP you will see a nice gain.
you will not benefit from the higher shift points
When my dad dynoed his GTP with rockers, the powerband didn't start falling off until ~6200rpms or so. Shifting at 6k instead of the stock 5500 or 5800 rpm shifts (can't remember what they are for his car) will make a big improvement actually. Shifting at 6200 should help a little as well. Any higher than that and it probably doesn't do much. My dad shifted his GTP at 6200 with his rockers and had a 6600rpm limiter and since he set all the stock cam/M90 L67 1/4 mile and dyno records, I'd say it probably worked ok. Although we never turned it that high on the dyno with the rockers, on the street it seemed to pull pretty hard all the way to the 6600rpm limiter with the rockers. Keep in mind however that this was done with 85lb. valvesprings and OR pushrods and should not be attemped with stock springs and/or pushrods.
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!