Quote:
Originally Posted by Sburn
Jack,
I was playing it very safe with the timing since my tank still had some 87 octane in it when I filled up with 91. I did a quick calculation of the mix ratio and gave it a little more retard to err on the side of caution.
Long term, I'm just a bit too thrifty to run anything but 87, so I'll probably go back to #2 tune, or maybe think about a custom #3 87 octane performance tune if there's any significant difference between that and the #2 87 towing tune.
Or....If the kind folks at PHP have a way to add a knock sensor or spark retard PID to the available Gryphon display gauges, then it would get easier to optimize the timing without going to far in the bad direction.
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I wondered if this was the reason for the spark retard (after I had posted, of course).
I have Scottish ancestry too - met Janet at Scottish Country Dancing! "If it ain't Scottish, it's CRAAAAP!"
I've never even tried the 91+ octane tune. There IS a difference between the "tow" tunes and the non-towing, "performance" tunes. Bill explained it once and it has to do with the fueling maps and shift points mostly as I recall.
A gent calling himself "Bluejay" over on the f150online forum says he noticed a big dropoff in power at high RPMs using a tow tune and loves his 87 performance tune from Bill. I thought Bill's custom 87 tow tune was great and for a while, that's all I had. Now though, I have a custom 87 "economy" tune too.
Again, welcome!
- Jack