I have a 94 ls with a custom turbo setup. The engine is bone stock, I have stock exhaust (for tuning), evo 19x10x2.5 ic, 2.5in down pipe, 2.5 in ic piping, and a small garrett turbo. The turbo is from a saab 900 16v, it is a TB0356, .42 ar compressor 45 trim, .48 exhaust. I'm running about 11 psi. Here is a compressor map here that I found of the turbo.
http://web.inter.nl.net/users/turbo-...e/compress.htm The stock saab engine made about 175hp at 5 psi (i think).

I'm doing all the tuning myself (rc 440 injectors using crome/wideband). I used my friends iphone's dynalicious program to dyno the car. The iphone said the car has about 260 crank hp, and I estimate that is roughly 220 whp.

My questions, do these numbers seem reasonable? How can my hp be higher than the flow of the turbo?

Thanks.

 

that sounds about right actually. .42/48trim turbo @ 11psi should yield ~220

 

Wow, thanks. I didn't believe it at first. What numbers could I expect with 15 psi?

 

thats probably a too much boost for a stock motor... (although after a second look maybe not since its such a small turbo) Make sure you know what you are doing with all the tuning...

Also why is the exhaust stock?

 

I've read that 15psi is about the max you can go with stock internals, I've had it up to 20 psi (in which my injectors dump a ton of fuel in so I don't blow it up).There didn't seem like much of a hp increase from 10 to 20 psi but that is probably due to bad tuning (running very rich and no I'm not boosting 20 anymore).

The stock exhaust is on so I can hear if it is knocking or misfiring (and whatever else you can hear), plus it's simply more quiet which is nice for cruising. I have an exhaust, I have just yet to put it on...

 

the backpressure from the stock exhaiust is horrible for your turbo set up.

 

How much can I expect to gain from putting the exhaust on? It's 2.5" with a high flow cat.