Wich Size Of Wastegate To Go?

[Nick378]

I'm aiming at 410 REAR WHEElL hp. I wonder, 38 mm tial or 44 mm tial? There is 200$ difference between them so i hop i can go with a 38 mm!

PS. I aim at 410 rwhp but i guess i'll make around 370rwhp

[The Dan]

First of all I would have to assume the engine you are using, then the revs you will be taking her to, then the turbo you are using.

So if it's an RB25 with a GT3X type turbo and revving to ~8krpm...

A 38 will do the job but bigger is better in this case. Better boost control will be had with the 44.

[Nick378]

lol sorry for the lack of informations. Your about right though!

It's a rb25det with stock internal. With a T31/T04e 60-1 with a 0,63 a/r

But i won't rev it to 8k.

Maximum 6900-7000 rpm.

[Nick378]

oh and what could be the best set-up possible for the wastegate piping on a stock rb25det manifold?

Cause i know that the piping can affect a lot the flow..

[The Dan]

lol sorry for the lack of informations. Your about right though!

It's a rb25det with stock internal. With a T31/T04e 60-1 with a 0,63 a/r

But i won't rev it to 8k.

Maximum 6900-7000 rpm.

I'd still use the 44. The gate pretty much has to be big enough to relieve pressure from the turbo enough to slow the turbine down sufficiently to maintain a constant boost level. If you go too small it will spike, sometimes harshly. As I said, a 38 will do the job, not quite sure if it'll spike for you as it's too close to call. Maybe you're paying too much for the 44 and if you found someone who could sell you one at a better price, you might be persuaded to get the 44 anyway.

oh and what could be the best set-up possible for the wastegate piping on a stock rb25det manifold?

Cause i know that the piping can affect a lot the flow..

You should put it as close to the base of the turbo as you can. You will need to have it spray welded onto the manifold as you can't weld mild steel, or anything else for that matter, to cast. It needs to be spray welded to deal with the expansion/contraction of the manifold.

Goodluck

[R31Nismoid]

Already a very detailed thread (from the Quick Ref sticky)

http://www.skylinesaustralia.com/forums/Fo...ick-t66556.html

Which you'll then find this thread linked.

http://www.skylinesaustralia.com/forums/ex...zes-t43638.html

Cheers