Already been searching the board a lot, but I still a couple of questions to ask:

1. is it harmful to run a 2.25 inch exhaust/ stock cat when turboed at just 6-7 psi? I know there will be a loss in power potential but will it actually do any damage? I may not have enough $$ to spring for a 3" exhaust/cat right away...

2. how does the car feel before the turbo spools up significantly. I mean before reaching full boost, will the car feel slower than stock or will there still be power gains through all the rpms?

TIA

 

I just got the GReddy Kit installed on my Si (18G), it comes with a 2.25 DP and its bolted to the stock cat and then to the stock muffler. It sucks, and I know once I open the exhaust up I will gain maybe 10-15+ HP. Its not harmful, just in the case of your gains will be lesser.

The car feels the same to me, but after 3500 RPM, shes all spooled and ready to go. This will dpends on the sizing of the turbo and your car. Almost like If i want to buy a PC, I have to know what its going to be used for. So with that with some turbos they will take more to spool, but the top end is powerful. Some smaller turbos tend to spool quicker but run out at higher RPM's.

Hope this helps.

 

well if your only boosting 6-7psi you don't need to spend $400+ on getting a 3inch exhust...instead i would get it tuned on a dyno. with $400 that is plenty for dyno time & runs.
-so i take that you have a common aftermarket exhust right? you'll be fine...the gains might be alittle like perhaps 3-8hp(since your not boosting high)

 

my car feels slower than it did before until i reach 3.5k (when it spools), i guess its all that extra piping that the air has to travel through