compression ratio ?'s

**cannotbeheldliable** · 04-11-2006, 07:28 PM

i am wondering what the possible benefits or negatives could be with adding a piston kit that changes the compression ratio to 8.5 for use with the sts turbo kit. will i lose horsepower if i go for the 8.5 vs the 10.5 with the turbo installed? would i have to use more boost with the 8.5 in order to make equivalent horsepower numbers of the 10.5? what would be the effects upon the block? i have read that going over 500 HP with the alumin block is dangerous. would the 8.5 increase the overall reliability and longevity of my engine when used with the turbo? sorry for so many ?'s i am new and trying to learn all i can. thank you for any input it is greatly appreciated. also if anyone has any good links where i could read to learn about this stuff i would appreciate that too. thanks for your time guys.

**Qwk94Z28** · 04-13-2006, 10:26 AM

Originally Posted by cannotbeheldliable

i am wondering what the possible benefits or negatives could be with adding a piston kit that changes the compression ratio to 8.5 for use with the sts turbo kit. will i lose horsepower if i go for the 8.5 vs the 10.5 with the turbo installed? would i have to use more boost with the 8.5 in order to make equivalent horsepower numbers of the 10.5? what would be the effects upon the block? i have read that going over 500 HP with the alumin block is dangerous. would the 8.5 increase the overall reliability and longevity of my engine when used with the turbo? sorry for so many ?'s i am new and trying to learn all i can. thank you for any input it is greatly appreciated. also if anyone has any good links where i could read to learn about this stuff i would appreciate that too. thanks for your time guys.

your on the right track, going to 8.5 yeah you'll lose power and need to run more boost to as if you ran 10.5 with boost. but the 8.5 is safer. if it was me i'd run 9.0-9.5:1 with boost and have done it no problem. all you need is some good tuning. i've also read myself the ls1 block can't take much over 500h/p so people opt for the iron blocks.

since ur new don't rush into things i spent almost a year reading everything till i boosted my first n/a car.