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WinRice WinRice is offline
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Join Date: Jun 2005
Location: Colorado
Posts: 700
Per the Porsche Technical Spec Manual

The US SC head has a system adjust pressure of 4.7 - 4.9 bar
The 930 head has a system adjust pressure of 6.2 - 6.5 bar early turbos, 6.9 - 7.1 bar late turbos

The first thing you need to do is get the fuel system up to the task with a larger single pump, or a dual 930 pump system. Then you need to shim up the fuel head to get a system pressure of 6.2 - 7.1 bar minimum.

One of the reasons the 930 uses a two pump system is the pressure boost you get from series pumps to get the high pressure (7.1 bar = 103 psi) needed by the CIS under boost. Most single pumps have a big drop in flow rate at those pressures.
1986 911 Turbo
3.3L, K27HFS, Tial 46mm, TurboKraft Intercooler, 964 Cams, Monty Muffler, MS3Pro Evo, M&W Ignition, Zietronix WBO2 Data Logger, Wevo shifter, coupler and motor mounts.
Old 01-20-2010, 08:21 PM
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