I was wondering what was the best HP/TQ gains on an aftermarket exhaust that has F/I.... I plan on going Turbo in a year or two and would like to start with exhaust now since it is within budget..... I'm eyeballing Stillen's.... I have a G35 Coupe btw

 

Generaly with turbo motors bigger is better so long as your ears can bear it. Turbos rely heavily on pressure differential between the exhaust manifold and the exhaust. So if the exhaust system pressure is lower then the manifold pressure doesn't have to be as high in order to achieve the same pressure differential across the turbine. This means less backpressure which translates to more power. An exhaust made for NA will not perform as well as one made for turbo once you add the turbo. But a better flowing exhaust will still be better than a stock exhaust.

 

First question I would have is: Is there a 3" exhaust on the market for the G? If not, look at a custom-made system from a local shop.

Second: What's the HP goal you're shooting for with the TT system? Will a 2.5" exhaust be big enough to support that figure?



'05 IP(or ?) 6MT... ...Never too soon to think about modifications!!

 

One thing to keep in mind is that turbos quiet your exhaust WAAAAY down so you can get by with 3" piping and test pipes (freer is better) with a TT setup that would be absolutely unbearable with a NA car.

If you go with a supercharger, you still need some backpressure.

--Steve

 

That depends on a lot of factors. Turbos do reduce some noise, but get a big enough exhaust, especially with a large turbo and you'll have plenty of exhaust noise. LArger turbos tend to need less exhaust energy once they are spooled and so th wasteget bypasses more air. This means more of the noise does not go through the turbo.