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      12-14-2013, 03:35 PM   #86
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Drives: 2015 M3 6MT
Join Date: May 2013
Location: Seattle

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Originally Posted by Boss330 View Post
Take a different car, the A45 AMG. It has a low CR at 8,6:1 but boost at 1.8bar, creating 360hp and a 223 number (psi x CR).

There are tunes from Renntech and Carlsson at 414hp and 450hp respectively. Pushing well above the "220 max limit"...
What is the psi with those tunes?
I suspect that gains are mainly made by less tapering and not by pushing peak bost. The question is, can the S55 stock turbos support less tapering?
A pure guess from me is, not much. Reasons being that minimum lag and high rpms are both M trademarks leading me to think that BMW selected small turbos and utilized most of their ability to pump air at high rpms already.

I do think they have left enough room for about a 5% or ~25hp power bump with the comp. pack. utilizing mainly peak boost ~4psi but this is just speculation.

Last edited by solstice; 12-14-2013 at 04:04 PM..