Thread: Got Good Fuel??
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Old 2009-03-15, 10:34 AM   #5
Dean
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Quote:
Originally Posted by Jcjentz View Post
yep its protuned and fine tuned for my mods and the altitude by Miles at FLI
fuel quality varies from station to station.. even same brand fuel..
been data logging and the D.A.M. is a good indicator on good or bad fuel
Not saying you didn't get a bad tank, and fuel quality varies, but not by that much. It is fairly well regulated and tested. Only in the rare case of a station tank getting filled with the wrong grade is the octane going to be off by more than a percent, nothing your car should notice especially at altitude.

I disagree. D.A.M. is an indicator of past knock, not fuel quality and a poor one at that. The ECU is VERY quick to pull timing advance and incredible slow to add it back.

Knock can be caused by any number of circumstances and it is seldom fuel quality especially from major name brands.

Any knock at altitude is most often tuning. With a good tune, in closed loop under load, your learned and real time A/F trims should be very low single digits both individually and total.

You didn't answer what mods you have and when or if you had been reseting and what your base multiplier is. Reseting makes a huge difference in ECU learning and how quickly it makes changes.

I am not familiar with Miles or FLI, where are they located?

Again, not dissing you, him, your tune, or anything, just trying to understand what is going on and offer feedback.
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Last edited by Dean; 2009-03-15 at 10:36 AM.
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