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RarlyL8 RarlyL8 is offline
Crotchety Old Bastard
 
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Join Date: Jan 2000
Location: Huntsville, AL
Posts: 13,525
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The problem is running out of adjustability. You need both the flow rate and the system pressure to be within spec for your application.
When the flow rate is brought to an acceptable level by lowering the system pressure you begin to affect other things such as injector and WUR function. Both those devices, and probably others, are set up to function optimally at specific pressures during specific times and temperatures. For example, the cacking presser for a 930 injector is ~40psi. The cold pressure that you might see with a system pressure of 65psi could very well drop below 40psi. Even at 60psi the spray pattern of the injector might be affected - I don't know that, just throwing it out there.
Pat, if I were you I might try to mimic the 3.0L 930 specs for the fuel system as a starting point. Your C/R is higher and boost lower but the resulting power and fuel needs should be similar I would think. Again, I haven't done any math and don't know the particulars of your engine.
Refresh my memory; will a 930 fuel head fit work with an SC air metering assembly? I just remembered I have a 3.0L 930 fuel head. It hasn't been used in a long time but you are welcome to give it a try.
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RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8
Old 06-06-2008, 06:21 PM
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