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Old 03-18-2009, 12:58 AM   #16
///tyron
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Join Date: Jun 2006
Location: whitby
Posts: 690
Quote:
Originally Posted by e30_kid89 View Post
.82ar will be good. size for a s52.

///tyron, I'd bet they use that t3/t4 for the m50 and maybe m52...I dunno if its me but a .63 seems on the small side for an s52 (3.2L)

Too much backpressure from small sizing = EGT's go through the roof.
It is small. I was just comparing the t3/t4 to the gt30r 1.06 a/r. If that turbo can make 325rwhp with a .63a/r on a 2.5L the gt30 with a 1.06a/r will flow well .

Big D If you look at the compressor map, you should require around 44lb/min of air. At your boost level of 10psi to make your power goal. that should indicate a 1.6 pressure ratio.

The Garrett turbo tech site says "this means that for any engine, in order to make 400 Hp, it needs to flow about 44 lb/min"

If you look at the map you're completely off the efficiency island. I'd say you'd have to run at least 15psi to be with in both the 30r and 35r's efficiency


heres a thread for you. S52 t3/t4 Pump gas 12 psi 360rwhp
http://forums.bimmerforums.com/forum...d.php?t=578916.
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