I had to do it 
S95/PT96mm crossover pipe sizing
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From: Port Tobacco, MD
S95/PT96mm crossover pipe sizing We're making 1 3/4" headers and using a 5" down pipe as far back as we can and downsizing to 4". What size pipe should you run between the turbo and the 1 3/4" header tubes? 3" or 2.5"?
Phil
Phil
im in the middle of a fab too. and was going to use my old 2 1/4 piping for my t91, but not sure if it is big enough. i maxed out my old pt88 at 22-24 psi. On the new set-up its a t91 and the same size motor "383" as before.....so i dont see that it will matter much if it is bigger.....but i would like to know if i need to go bigger too.
Last edited by otherwhitemeat; Jan 8, 2007 at 09:26 PM.
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Originally Posted by Phil99vette
We're making 1 3/4" headers and using a 5" down pipe as far back as we can and downsizing to 4". What size pipe should you run between the turbo and the 1 3/4" header tubes? 3" or 2.5"?
Phil
Phil
Is this a race car with the 1 3/4 headers? Spool time?
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Originally Posted by 1fstTA
use 2.5 your spool time will definitely be slower with the 3ich.
That's from Brent Davis on turbomustangs.com. He claims to make full boost on the street at around 4000 RPM's with a 306" motor and a Majestic T4-frame 88mm turbo. I really don't think a 3" crossover will hurt you at all, I did a friends car with a 284" modular with a 3" crossover and a GT47-88 and it doesn't seem abnormally slow to spool.
Originally Posted by DrTurbo
We use 2.5", and we have made 1500rwhp with 1 5/8" primaries.
Yea, that's why I was asking why he was going with 1 3/4. Jim used 1 5/8 on mine and it seems to be working well.
Staging Lane
Joined: Oct 2004
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From: In the garage
Small block Chevy
1 7/8 header with 2.5 crossover...2000hp
My own 23* motor made 1500hp with 1 5/8 and 2.5 crossover
Why go bigger. You still have to neck that pipe down into a merge at the flange
1 7/8 header with 2.5 crossover...2000hp
My own 23* motor made 1500hp with 1 5/8 and 2.5 crossover
Why go bigger. You still have to neck that pipe down into a merge at the flange
