3 or 3.5" downpipe for a pt7675 cea?
Thread Starter
Joined: Dec 2007
Posts: 734
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From: Rittman, Ohio
3 or 3.5" downpipe for a pt7675 cea? Im in the works of turboing my truck and im stuck on deciding what size downpipe to build. They make flanges to accept either size. The outlet is 3" but ive read bigger is better for downpipe size. So is there a difference on this turbo?
TECH Enthusiast
Joined: Mar 2010
Posts: 519
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You can always make it 3 inch until it is under the vehicle then step up to 3.5-4 inch or even split it to dual 3 inch if it is a vehicle t hat normally has dual exhaust exits.
3 inch is okay if it is a short run, also depends on power level and cubes.
3 inch is okay if it is a short run, also depends on power level and cubes.
Thread Starter
Joined: Dec 2007
Posts: 734
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From: Rittman, Ohio
I orginally thought it had a 3.5 outlet so I planned on running 3.5" all along because I think itll fit. But once I found out the vband is 3 5/8 but actual outlet is only 3" I questioned if I should still go with 3.5 or stick with 3.
9 Second Club
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From: Joliet,IL and Las Vegas 50/50
I have a feeling I was choking on backpressure with my 3" on a pt7675 pushing about 20psi. If you can do a 3.5", do yourself a favor and just do it. That was a big regret of mine was not going larger on the DP. Look at it like this, going 3.5" isn't going to hurt anything so just do it for peace of mind
