FMIC piping Q?

[blkb6a4]

So I'm working on putting together everything I need for my GT3071 build and I'm wondering what size fmic piping I should be running 2.25 or 2.5 or somthing totally diff. Thanks guys

[biketsai]

for a Gt30, im gonna have to say 2.5"

[blkb6a4]

thats what I was thinking, I was going to do 28r and then didn't wanna do that many stages so I'm building the motor and slapping on the turbo this winter.

P.S. If anyone in the minnesota twin cities area with previous knowlage wants to help build my motor somtime in the next month or two let me know, I am willing to pay you or just supply the beer for the weekend, if you have to travel i'll pay for gas and you can stay at my house...just send me a pm

[mike-2ptzero]

Best to match or get very close to the size outlet of the turbo. The GT3071r uses a 2"(50.8mm) outlet, so you might be better off with 2.25" so it can keep the velocity up.

Funny thing is the Greg just went from his old FMIC that used 2.5" pipes on both sides to a ER comp that uses 2.25 on the hot side and 2.5" on the cold side. He was driving the car this weekend and just noticed that his car is making 3psi more boost then it was with his old FMIC.

[njm23]

Thread jack,
Mike what are the benefits of running the larger pipes on the cold side? I dont get why not just run the same size all the way through?

[mike-2ptzero]

Thread jack,
Mike what are the benefits of running the larger pipes on the cold side? I dont get why not just run the same size all the way through?

Volume and the tb is larger. Velocity on the hot side to help push the air thru the core.

They say that there is a speed range that you want to keep the air flow, if it gets too high the pipe size is a restriction and if it is too slow causing the air flow to stall the pipe is too big.