1stealthls

i have done a search but im still confused isnt a usdm b20z and a jdmb20b
have the same horsepower (146) and the usdm b20b is the lower hp motor im going b20 turbo but i want the 146 hp can you guys help me out a little thanx

dlric

yes and yes

daver

I understand that having the lower compression pistons is better for the turbo setup.

Type-ARR

not really

blkwidw96

it's not better it just allows you to run more boost with less tuning. It really just depends on the goals for the engine though. Ig you are going daily reliability it may help out but other than that go as high a compression ratio as youi can tune the engine for

RMS

Lower compression allows you to run MORE boost with the same fuel octane...all things being equal, including your tuner. High boost and high compression are hard partners in a street car. One run on a heat-soaked intercooler can spell dissaster for a high compression engine while the more conservative compression is far more forgiving.
I've always wanted to see a fair comparison of HP maxed out on 92 octane with high vs low compression with boost and letting knock be the only limit. My guess is that timing retard on the high compression engine will cancel gains in efficiency realized by the lower compression engine. Anybody seen published results relating to this?
When octane is not an issue even iron domestics run 15:1 with 40+lbs of roots boost.