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vichang4 vichang4 is offline
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Join Date: May 2003
Posts: 132
I'm rebuilding my 87 930 with 7.5/1 RUF pistons. They are also 98mm (stock 97mm). Sould be together in a couple of weeks. I'll let you know.

Using the formula ECR= SCR * sq rt [1+ (boost/1)]
boost in bars (ie 930 full boost .8 to 1)

7.0 to 1 stock @ 1 bar = 9.9 to 1 effective comp ratio
7.5 to 1 RUF @ 1 bar = 10.6 to 1 effective comp ratio

with 10.6 ECR you better run high octane or back off the boost.

7.5 to 1 RUF @ .8 bar = 10.0 to 1 effective comp ratio, very close to stock.
__________________
Victor Toce
2000 Boxster S w/
Tequipment exhaust
1993 Spec Miata
87 911 turbo - sold
3.4 RUF pistons and cylinders
Euro CIS head
Old 04-07-2004, 08:39 PM
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