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911st 911st is offline
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Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
Here is an example of a good stock AFR curve. Note that the fuel curve is most rich where TQ is peaking as that is where we are most sensitive to detonation. After that point we gain some HP by leaning up a bit.

Near perfect fit.

It is when we start gulping air faster that we blow through the AFR curve.

Originally Posted by krasuskyp View Post
Stock '87 mit 40k miles, 'cept for gutted cat, GReddy Profec B Spec II MBC set to 0.8bar, and spring centered clutch. Sea level, maybe 60F, Mustang dyno.

All in all I'm giddy at the curves - AFR's were so spot on Tony didn't even want to bother tinkering with anything, let alone pulling a 3rd pull - sweet! I basically called the whp dead nuts (I predicted 250whp, and was 249 before "smoothing), while torque on the other hand was waaaaay beyond expectation (even moreso before smoothing).

Just a note, most car makers program there turbos to run in the 10's on boost to protect the motor. We seem to want to be in the mid 11's with higher boost but there is more power in the 12's if the boost plus compression thing is not to high.

Last edited by 911st; 01-25-2010 at 03:37 PM..
Old 01-25-2010, 03:27 PM
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