3 inch straight pipes Z32 TT?

[z32_Chase]

I was thinking about putting dual 3in Straight pipes to dual 3in tips with a resonator on each love the sound of the turbo spool . So what im wondering will doing this mod decrease Hp due to less back pressure etc

[2_Liter_Turbo]

Back pressure is a bad thing, no matter which engine you have. It's an old muscle car era misnomer. What these guys were actually referring to was the exhaust scavenging they got by running the correct sized exhaust (header on back). On a non-turbocharged engine, having the correct sized exhaust based off of your engine specs is crucial. This is why a large exhaust on a smaller N/A engine will lose power. HOWEVER, on a turbo car things change up a bit. After the turbocharger, it is best to have a rather large exhaust with mandrel bends (turbine exhaust spirals down the walls of the exhaust rather than "pulses" like normal exhaust to put it in simple terms).

So in short, running a dual 3" exhaust will not lose horsepower, in reality, it will be an improvement.

[z32_Chase]

oh ok ive been told you need back pressure but i guess he doesnt know what he is talking about so.. thanks!

[Slizz]

oh ok ive been told you need back pressure but i guess he doesnt know what he is talking about so.. thanks!

[NolimitZ32]

once you have an open exhaust on a turbo vehicle, it is important to maintain velocity until the gasses exit the pipe, this means that in essence you need an exhaust that will taper smaller as it gets closer to the outlet to ensure that the available volume decreases with the contraction of the gasses as they cool, in reality I don't think there is much of a difference if you run full 3" or 3" to 2.5" but then I've never been involved any dyno sessions to prove this either way.