Thread: 3.5 and 4 inch exhaust... whos gottem

Like chappy said. you wont really need bigger then 3" esp for the catback. downpipe if you really wanted to you could go 3.5", ground clearance would fo sho be an issue though

I mean think about it. if your turbo outlet is sized 3" then there really is no reason for going bigger.

if its sized for 3.5" then go 3.5" on the down pipe.

if you have a car making more then 500whp chances are you don't need a full exhaust so dump it somewhere up front of the car.

that burns exhaust is deff best ive seen on a sentra. must have cost a fortune!!!

I say titanium is the way to go if you wanna be ballin...

If you don't have your Watergate routed back into the downpipe that does help relieve flow aswell.

My boy johnny isnt around anymore but he had a b14 DET with a GT35 at 18 psi iirc it was dydno tuned to 535 it was later street tuned to 32psi , but he had 4in straight pipe...

even if the outlet on the turbo is 3" the exhaust gas's will want to expand when exiting the housing. so bumping up to 4" will actually help you a lot. i would love to do a 4" down pipe on the G20 but issue is the roads here suck and my wife will be driving it daily so it will get crushed quickly so 3" it is so it can stay tucked nicely. when you restricted exhaust flow you are also creating unwanted/needed heat, so if you can, why not just make a larger dp and put the biggest setup in there you can fit



that is not 100% true

How so, its less volume running through the exhaust?

You can actually induce a venturi if it's routed properly, which will help with exhaust evacuation out of the wastegate and prevent any kind of boostcreep. It also sounds way better IMO, I hate dumped wastegates. Had it for two weeks, never again, lol. On a street car of course.

This ^^

4"

albeit on an N15/B14 chassis

The exhaust is nicer then that car is haha.. rust is scary