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      04-11-2010, 01:47 PM   #2
e.n335's Avatar

Drives: e93 ///M3 DCT, 07/2009
Join Date: Feb 2007
Location: Switzerland, ZH

iTrader: (0)

Originally Posted by Bob MG View Post
Nice numbers LV!!
Different cars can be just stronger from factory. We hve seen as much as 40 HP differences.
Roman gave me a 95mm pulley for
my kit due to my mountain goat altitude of 5000ft!
I'm running DCT to so hopefully it will get me close to 5,5psi
A centrifugal type supercharger does not provide absolute boost like a turbocharger, it provides relative boost due to the fact that the speed of the compressor is directly related to the engines rpm. So at 5000 feet your stock car has -2.5 psi "boost pressure" compared to sea level ( 0 psi ). To get out 5.5 psi @ 5000 feet your SC kit needs to make 8 psi boost at sea level. How do you manage those 8 psi once you really leave your altitude ?