Downpipe size T70
Thread Starter
TECH Enthusiast
Joined: Jan 2004
Posts: 608
Likes: 0
From: New Zealand
Downpipe size T70 What size downpipes are you single T70 guys running ?
Exhaust side of turbo is 3" , are people just running 3" downpipes or stepping up to 3 1/2" or even 4" ?
aim is for 550-600 RWHP.
Cheers
John
Exhaust side of turbo is 3" , are people just running 3" downpipes or stepping up to 3 1/2" or even 4" ?
aim is for 550-600 RWHP.
Cheers
John
Last edited by Johnv; Sep 1, 2006 at 03:42 PM.
Thread Starter
TECH Enthusiast
Joined: Jan 2004
Posts: 608
Likes: 0
From: New Zealand
Originally Posted by DrTurbo
All you need is a 3" DP.
If not 3" would be soooo much easier to squeeze in there anyways
TECH Addict
Joined: Jul 2005
Posts: 2,153
Likes: 3
I was running 363 cid with a T-76 turbo and a 3" downpipe, stepping up to 3.5" for the cat-back. With no muffler, my backpressure at 18 psi boost was 34 psi.
I later built a 377 cid with the same T-76 turbo, but with a short 3.5" downpipe and no cat-back. At 18 psi boost, backpressure was only 26 psi. Most people say that low backpressure is not possible with a T-4 turbo and 350+ cid, but I guess with only 2 ft of large exhaust and efficiently designed headers, you get get there. .
Mike
I later built a 377 cid with the same T-76 turbo, but with a short 3.5" downpipe and no cat-back. At 18 psi boost, backpressure was only 26 psi. Most people say that low backpressure is not possible with a T-4 turbo and 350+ cid, but I guess with only 2 ft of large exhaust and efficiently designed headers, you get get there. .
Mike
