71chevellels1

iTrader: (13)

Im running a 76mm turbo and my exhaust outlet on the turbo is 3.5 inches but i want a run a 4 or 5 inch DP. Its just going to be a 90 degree dump so do i buy a 3.5" 90 bend and a 4 or 5 inch to 3.5 reducer? What are you guys using? Thanks

pwrtrip75

iTrader: (8)

depending on how long your exhaust is, each elbow adds the same flow as like 4' of straight pipe (something like that) So the more elbows you use it is better to step it up. If it just a dump, I'd leave it at 3.5" ........my opinion.

White.Lightning

iTrader: (53)

Isn't 3.5" sufficient for a 76mm turbo? I see some 88mm guys running 4" DP's.

Andy

Turbo LS1 SS

iTrader: (7)

3" is enough for a 76gts, especially if it's dumped.

been there done that

Big Geek

iTrader: (2)

I have seen gains made by swapping out a 3-in. DP to a larger 3.5 and 4-in. DP. This is not to say that you can't run the numbers with a 3-in. as I have seen some do just that, but as I stated I have seen cars pick up power and ET by upping the DP size. It is a good rule of thumb to utilize as large a DP as reasonable, it is one of the few areas where most of the time bigger is better. Hope this helps.

Jim C.

70Stang

iTrader: (2)

I would go 3.5" to 4" and then dump it...

fullthrottledan

iTrader: (2)

this gets my vote too. Ive got a 3.5" outlet on my turbo and bumped it up to 4" all the way back. good enough