Question : Lowering compression for S.C.

[herbykw]

I have a 2002 Monte Carlo SS with the 3800. I found a supercharger kit for it, but i know i have a high chance of damaging my engine if i just slap it on there. The Montes that are SC have a lower compression ratio, then mine. I have some basic knowlege of how the engine works, but i am no mechanic. Swapping the intake and adding the SC i can do. But how can i lower the compression ration so that i do not blow my engine? and without spending large amounts of money. Thank you.

[bszopi]

I wouldn't worry about lowering the compression. You'll just need tuning and MAYBE higher octane gas and you'll be fine. I'm not 3800 master, but I'd suspect that the difference is maybe 0.5:1 (ie, 9.8:1 and 9.3:1). You'll be just fine with the slightly higher CR.

[Z26-T]

Didn't know that the super charged actually did have lower compression till I looked... Yours will have 9.4-1 and the super charged versions have 8.5-1. Which probably isn't what you were asking...

Personally I would just find a monte that has a supercharger on it and take everything out of it and put it into yours (entire engine, harness, etc.)... Unless you want to just use the kit, in that case you can just put it on with your stock compression and adjust for the boost by adjusting your fuel/timing. You can put boost to 9.5-1 if you can tune it...

[Wiz85]

I don't know what octane the SC Monte's run but with 8.5:1 cr and running 6 psi max calculates out to roughly 12:1 cr max static. Now running 9.4:1 cr with 6 psi is roughly 13.3:1 cr. Depending on combustion area volume and some other things, you should be able to tune for it.

[grandprixgtp_91]

you can buy turbo kits for the n/a 3800 that will run over 9psi and lay down over 400hp at the wheels, and they do it all on a stock motor, so i would not worry about it, i installed one of these kits on my buddies 2001 GP and it works awesome, makes me wish i had a 3800 too, lol for 2 min.

Jake