No, it's called knowledge from experience. I've been tweeking and racing inports for almost 20 years. And in my experience, a T3/4 50 trim should have no problem doing 275HP on a B18. Unless of course, some retarded ---- is done on the build/setup.

BTW, why are you always trolling this forum for a pissing match? Contribute something worthwhile, or STFU.

I have been hesitant to run the turbo as it sits with the .48 housing, I have heard once i reach 5 to 6K rpm it would choke causing it not to pull anymore rpm and run like crap.
is that true? if so I'd like to get a .63 and not have to install then reinstall the turbo.

No, that's not true. At higher RPM's, your enigine will need more CFM than a smaller turbo can provide, so your power will start to trail off. BUT..., you will still be flowing way more than a factory engine under vacuum, and therefore should make more power. If you want to switch to the .63, do it. But I wouldn't say it's NECESSARY to make good power on that motor. Anyone on here running a 14b can attest to that.

Do you feel i will make my goal of 300 whp using the .48 housing @10psi?
from all my research i have found most people try to stay in the 10-12psi range on a stock GSR..any thought on that?

If you don't hit 300, you should be close. There are a lot of factors that could affect that. How many miles on the motor, how hard it has been driven, how good your tune is. I would say stay around 10psi on a stock motor to be safe. Unless you have a different motor to drop in, you don't want to boost a DD too hard. The most important thing will be your tune. Get someone that is good, and spend AT LEAST an hour on the dyno with him to get it where it needs to be. What injectors are you gonna run?

I currently have a set of DSM 450's...I hope they will support 300 whp..

For my experience i think the best choice must be the .63 hotside. On my cars even with a SOHC engine they starts to spools fairy quick around 3k - 3.5k and last a li`l more at higher rpms. I have right now a t3-t04 .63 .60 turbo and pulls really nice on my SOHC.

Thats only my opinion

They weren't designed to support 300 horsepower.

Hoping injectors are good enough = blowing the rings to pieces or smoking a piston.

Oh and for the record, stock DSM 450 injector's are maxed out around 83-85% injector duty cycle, not 100% like everybody thinks. The injectors they run in older F1 cars that cost over $2000 a piece can only hold 93% injector duty cycle for about 25 seconds before they start to skip. Crappy/worn out/mass produced injectors however do not conform to those standards and shouldn't be pushed harder than 85% injector duty cycle because they might not fail, but the will start to fatigue/over heat and skip. When an injector skips about three times at 6000+ rpms, your pistons take the abuse.

But this is homemadeturbo... ;D

UPDATE, I was able to get a .63 housing!!!
for 300-350 whp what injectors do you recomend?

i was saying how would you know the amount of power he would make at 8k rpms. im sure with that tiny .48 housing it would drop off a bit before 8k choking the motor. so why dont you knock off that internet tough guy bullshit and stfu your taliing out of your ass faggot