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hi

now i recently drove someones a31 cifero and he has a rb25det with a automatic transimssion. He upgraded the turbo and installed a external wastegate with a screamer pipe vented into the atmosphere . Sounds excellent tho

now can someone explain to me whats the point of the external wastegate? and should it be vented into the atmosphere? or would it be better to bring it back into the exhaust system

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Legally it should always be plumbed back into the exhaust for sound and emission polution reasons..

On a racecar it "might" make some useful difference..

on your mates car with an automatic transmission (which I am assuming is not a racecar) it is just a wank along the same lines of an atmo BOV...

It's better venting it to atmosphere. Less gas disturbance, lower exhaust pressures, more power. Trade off is noise, and as Artz said, it's illegal without its own cat converter and muffler system.

I lost 17kw plumbing it back in.

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