Remote style turbo setup, size piping question

[LamboZ]

Im NOT talking about a STS style turbo kit.

 

I have a custom tubular exhaust manifold thats all equal length, but the turbo im running is too big for the area it sits in. So I wanted to make a pipe that goes from the flange on the manifold and bring it foward to mount the turbo up front where the radiator sits (much like how the unlimited street tire mustang guys do with there turbo setups). Im sure a bigger size pipe would mean more lag, so I wanted to do this correctly.

 

The turbo is close to size of a GT35R, the manifolds piping is 1.25in's each, the flange on the turbo is a T3, the downpipe size is 4in.

 

I was think using either a 2.5in or a 3in pipe from the manifolds flange to the turbo would be good, I just don't know which one would be the best.

 

What do you fella's think?

 

Thanks ahead of time for all help given!

[510six]

Is this on an L series, some pics of your setup/dilema would help.

[LamboZ]

Yes its on a L28 and in a 240Z.

 

I would love to provide pictures but no luck on a camera.

 

Best way I can discribe is my turbo is too big in size for where it would sit on my custom manifold. It allows no room for the 4in downpipe, it hits the brake lines, and also hits my intake manifold. So I would like to take a pipe and go from where the turbo WOULD sit on the manifold and bring the pipe foward so that the turbo can sit alittle higher and right near where the factory radiator sits (on the side of it).

I have a custom radiator that isnt as wide to allow me to do this.

 

I guess you can say it's almost a setup like how the V8 guys turn there headers around and bring them both into one pipe. which that pipe is towards the front of the engine bay.

 

Im just not sure on what size piping to use. 2.5 or 3in.

Im sure it will make a difference and rather just do it right the 1st time.

 

Sorry if im not making much sense.

[Clifton]

Got a pic? GT35R's aren't that big. I have no problem getting a T series on mine and other have too and I know TimZ on here has a GT42.

 

As for tube size 3" is way to big to feed a GT35. If you are going with a GT35 you aren't going to need 4" exhaust. They just won't make that much power. I would somehow make it work and use a 3" out.

[WizardBlack]

Straight answer. Measure the perimeter of the opening of a T3 flange and calculate what diameter piping has the same perimeter. Then fab up your pipe how you need it and have a machine shop press the pipe into the flange and weld it. The beginning and ending of this adapter pipe is going to both be a T3 flange so you know precisely what pipe you need. The alternative is to use same area, but I prefer perimeter for smooth transition.

[LamboZ]

Clifton - No picture sorry. Like I said this is a custom manifold, so where my turbo sits on this manifold it hits a few things.

Also its not a GT35R. Its bigger but size wise its close so I just said a turbo that many people know about.

 

WizardBlack - I was thinking that but the manifolds flange is a T4 and the turbos flange is a T3. So the flange openings are different size's. Thats why I wasnt sure on the 2.5 or 3in.

 

Ill just do 2.5" and see how the turbos spools.