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      12-22-2018, 10:22 PM   #66
wfdeacon88
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Drives: E90 M3
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Quote:
Originally Posted by Freiheit View Post
Quote:
Originally Posted by wfdeacon88 View Post
hmm... would it be enough for a stage 2 tune also?
I would think so. The stage 2 tune works with deleted primary cats but leaving the rear cats in place, so you'd simply move those cats forward to the primary location. They'd get the exact same exhaust charge as they would if you left them in the back and test piped the forward section. They'd actually work slightly better since they'd pick up more heat from being closer to the combustion event.

Does anyone know if the stock primary cats are metallic or ceramic substrate?
so essentially you'd need no test pipes, just some sort of steel pipe in the place of the secondary (where is was)?
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