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I have bought a Tial 44mm wastegate kit for my single turbo RB25 engine which should make 500 flywheel horsepower 370 Kw). I have an all steel RB26 in build, which I want to put something like a GT4088R on, and hope to make a maximum of 700 BHP (520 Kw) on race fuel. Is this same wastegate big enough, or do I need their 46 mm one?

Thanks.

There is a long thread on how ot size wastegate correctly, here is the abreviated version.....

I have pretty good success using this formula to determine external wastegate sizes;

Airflow in lbs per minute = diameter of wastegate in mm X boost correction factor

So let's apply it to your car;

300 rwkw = 480 bhp

480 bhp = 44 lbs of airflow = 44 mm wastegate

Now if you want to run 19 psi, then that's the right size wastegate.

But we need to apply the boost correction....

My experience indicates that to get 300 rwkw out of a GT3040 you would need to run around 1.5 bar (22psi). So using the formula...

44 / 22 X 19 = 38 mm.

For those who haven't read the thread..............

http://www.skylinesaustralia.com/forums/sh...ead.php?t=43638

Hope that helps

:dry: cheers :thumbsup:

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