Depending on your mods it can add 5-15hp, with a custom tune and/or adjustable timing and whatnot, it can add more. However, the cost is $200 +/- depending on who you buy it from. It will raise your shiftpoints, raise your downshift points (so for instance on an L67 car it would downshift into first at 40+mph instead of 35), raise your rev limiter, increase firmness of shfts, and get rid of your speed limiter (well, actually it just raises it really high). It also gets rid of most of the torque management crap that the SSEi PCM'* are cursed with. It changes the fuel and timing tables to give you better power, a richer fuel mixture, and usually it lowers your KR. It also quickens your KR reduction rate. Depending on your mods and such, it will gain you 1-3 tenths in the 1/4. On a minimally modded car (intake, pulley, exhaust), it will be a lesser gain of like 1 tenth, whereas on a more modded car (headers, rockers/cam, I/C, etc...) it will usually give a larger gain.
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!