Thread: high compression, low boost. lower compression, higher boost

I'd prefer low compression, more timing and boost. Less chance of popping a piston I think. But it really would come down to the tune.

Originally Posted by Fivefingerdeathpunch

I'd prefer low compression, more timing and boost. Less chance of popping a piston I think. But it really would come down to the tune.

agreed, plus it's fun to tell people that you're running 23 psi of boost. In the end, lower compression is the "right" way of doing it, hence why FI cars come with lower compression from the factory, more reliable.

Higher compression for the POS m90, Anything else with a decent FI set up lower compression, but to answer your question if its pertaining to the m90 then higher will win hands down.

I <3 my low compression...granted it is higher than the factory 8.5:1...but it isn't quite near what a N/A motor makes...9.4:1.

A higher compression motor (if we are comparing apples to apples on pump high octane, say 93) can't run as much boost and timing as a low compression motor...BUT...the higher compression makes up for that extra boost you need to make with the low comp. motor to make the same numbers...high comp. motor will make more power out of boost and won't have as much parasitic loss as a high boost, low comp. motor would...nor would you take the risk of such high a timing car like a low comp. high boost car...but then a high comp motor that is boosted runs the risk of popping a piston easier IMO, spot on tunes would cure that but if your tune isn't accurate...it's a damn ticking time bomb.