Turbo Selection - 4cyl - 300rwhp?

[roz85]

The engine (4g54) is currently making 303rwhp @14psi using a hiflowed to4 (1.06a/r exhaust, .60a/r comp). Fullboost is somewhere around 4500rpm, and am looking to change for something that makes similar power but which has usable power lower down in the rev range. Is it possible? Perhaps go for something a little newer/BB - GT range?

Is it possible to make similar power, having usable power down low or are my expectations too high? Suggestions?

[RS500]

why don't u just go for a A/R .84 exhaust housing?

this will help bring the turbo on earlier and still give u the top end (maybe a little short of 303rwhp but not that far off) that u want - hence a broader power band.

btw, what spec wheels do u have in your turbo?

[roz85]

unsure of wheel specs, has some spec sierra wheel in it.......

[RS500]

i had the same exhaust wheel in my sierra cosworth with a split-pulse A/R .84 exhaust housing, and it made ~300rwhp on 16-17psi with a wide power range (4000 - 7000rpm) with more potential as the power was still climbing at the 7000rpm limiter.

btw, the compressor wheel was a 60-1.

[NXTIME]

There isn't a need to change a good combination if you only want to shift the power band. I agree with RS500, get your hands on a 0.84 a/r exhaust housing and you will be quite satisfied with the resulting lower power band. I currently have a split-pulse 0.70 a/r TO4 on my SOHC G63B and I get boost at 2800 in 4th with full boost at about 4000-4300 and my car is not tuned properly.