Turbo v6 exhaust size???????????

[Blakvsexec]

My turbo has a 3" v-band outlet, should i continue it at 3" all the way through

or

Should i reduce it back down after the dump pipe

I know on diesels the exhaust should be free flowing on a turbo engine but is it the same for a petrol engine???


Cheers

[2DIE]

I think twin 2.5" or a single 3" should be fine from reading about 100 of these posts

[Blakvsexec]

A twin 2.5 is bot possible as i am only running a single turbo and only have a single outlet

[delcowizzid]

im going to twin 2.5 soon when i have the spare cash for bends you just go from 3" dump into twin 2.5 makes them sound better YouTube - Brutus in the driveway running!

[soop]

Turbo exhausts have totally different princible's.

Run a single 3" as a minimum.
Or depending on boost and HP, 3.5" tapering to a 3".

[delcowizzid]

still just the same principle i went from 2.5 to 3" and lost low down torque cruiseing but gained heaps 0-100 at full throttle you still get a trade-off just like N/A and with some extra timing you can make up for the torque loss down in the cruise area

[soop]

Totally depends on the turbo really.
Better idea is to go 3" tapering to 2.5 if you're only running a mild setup.
Also, the Dump pipe design is critical. I've seen some SHIT dump pipes being used on Commodores.

[delcowizzid]

7psi you strangle the shit out of them with 2.5" exhaust ive been looking at 3.5" or 4" for a while now to open it up some but 3" is good for 11's so far see what difference it makes straight out the dump in a month

[soop]

Becarefull that it doesn't surge like a mother with no exhaust on it .

How have you delt with the waste gate, is it internal or external?

[delcowizzid]

it has good enough fuel in it that it could surge to 18psi and survive pretty well on its own wastegate cheap as chips chinese special 38mm never spiked in its life

[Blakvsexec]

Mine being a daily driver i dont want to lose the low down torque so this is something i might have to have addressed in the tune, i also would like for it not to be extremely loud i dont want to be attracting the wrong type of attention.

My Turbo is a GT3582 with an internal wastegate and has a 3" v-band outlet, i intend on making a nice smooth flowing 3" stainless dump pipe and was going to send it through a 3" mandrel bent system like this one



Your opinions are welcomed

[soop]

Have alook into Bellmouth dump pipes. Can really increase the performance of the turbo.

[Claudy]

Mine will be 3" with a metal high flow cat and a 3"straight through muffler

[Blakvsexec]

Yeah Claudy, thats what i have decided.

I have picked up a 3" 200cpsi magnaflow cat off US ebay for $100 for mine as i am going to build the system myself.
I got a quote today for a 3" catback with 1 straight through muffler and was quoted $470 thats in mild steel.
I can do my dump pipe, flexi bellows, cat, and exhaust pipe all in stainless with mandrel bends, and a mild steel muffler for only $400.