People that are making 400-500whp, are you using a 3 inch exhaust or are you just using a 3 inch downpipe and then to a 2.5 inch exhaust. I'm coming from a turbo car where I ran just open downpipe and that was obnoxius loud and I will not ever do that again.

 

3" downpipe and exhaust

 

Im looking for a company that has a 3 inch dual setup, I searched but havent came up with anything yet

 

Bulletproof has a 80mm dual (3.15 inch) from Tracy Sports. It's a bit pricey and very lightweight. I'm running the 70mm (2.75 inch) dual and it is very loud.

I tested a 3-1/2 inch system and the 70mm system appears to make equivalent power.

 

Check out turbo-mafia.com and they will custom make the exhaust for you. I just ordered a new single from them and can't wait. Right now they're doing a group pricing so you might want to take a look at that.