kashman15

I'm still learning about turbo and its facts but i hear that the lower the compression the better the turbo performs and higher compression is better for N/A engines. If this is true can anyone explain how to lower 10:1 stock compression or are there any links? any help is appreciated.

Mad-MAX_SE

iTrader: (2)

you can change the compression of an engine by using a larger (thicker) head gasket, changing the pistons, or, according to Icey, by using a head with a larger CC. No matter what you do, it's not something that is a simple job.

I30tMikeD

iTrader: (8)

Having a lower compression just allows you to run more boost, the turbo does not "perform" any different. A maxima running 10lbs of boost at 10:1 compression will perform better than it would at 10lbs of boost at 8:1 compression. There will be a certain point at which the lower compression motor, which can handle more boost, will start to out perform the high compression motor but it will not be until 17, 18..20 lbs of boost

Stephen Max

iTrader: (59)

Also, keep it mind that the lower the compression ratio, the less crisp engine response is during normal partial throttle driving. Taken to the extreme, a low compression engine with high boost is very mushy feeling until you floor it, then you get a white-knuckle wild ride. You lose a lot of driveability and the car gets to be a pain around town. But lowering to 9.5 or 9:1 will allow for more boost before the onset of detonation (all else remaining the same) without a very noticeable change in engine response.

superdave2

Just a side note...
I have considered having my head shaved to RAISE my compression on my SR20det from 8.5: to 9:1. If I decide to go for a bigger turbo than my GTiR t28 then I won't do it. But the original plan was always to make a smaller turbo fed street machine to take to the local circuit track on the weekends. IMO a smaller turbo with higher compression is better suited for this.

IceY2K1

iTrader: (3)

Lowering compression just allows you to run more boost on pump gas. The higher the compression the more power you'll make as long as the fuel grade/type can minimize detonation.