engineermike
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The Gen3 Coyote PCM logic really is amazing. It will do things that Gen2, Ecoboost, and even GT500 won't do.
I've posted about my 2020 F-150 several times before, so here's another one. As most know, the Roush supercharger has a charge temp problem that severely constrains power when octane limited, but isn't such a limit on E85. I installed a smaller pulley to raise the boost up and take advantage of E85, which works against me on gasoline. I had already turned on flex fuel in the truck and have spark timing increase or decrease with learned ethanol. Now, I added a load limit that also floats up and down with learned ethanol. Just to prove it out, I set a load limit of 1.0 under 50% ethanol, ramping up to no limit at 60%. The following snips are from one continuous log just after switching from gasoline to E85:
This is immediately after a fill-up with E85. At this time, gasoline is still being delivered to the engine because the fuel system was not yet purged of the olf fuel. You can see that the AFR status was actively learning, triggered on by the fill-up. Pedal is to the floor, desired load is 1.00, and actual load is 1.025, following the gasoline load limit applied. Boost pressure is about 2.5 psi.
I have it set up to add 8 deg of borderline timing between 50 and 60% ethanol:
Here you can see the ethanol learning increasing from 55 to 60% and the borderline timing increasing with it. This is the timeframe over which the flex fuel load limit is also released.
This is 12 minutes after the first snip, in the same continuous log. It didn't quite hit the 60%, but it was close enough to allow the throttle to fully open and the load went past 1.6, boost being about 13 psi. The desired load was lower than actual because only torque demand was setting the desired load, and some other settings in the logic will still push the blade open if driver demand is limiting desired load.
So for everyone looking to get the most out of their flex-fuel supercharged mustang, just know this is possible just by turning on and tuning the stock logic. You can pulley down as far as you want on E85 and set up a load limit on gasoline, which will limit boost as a result.
I've posted about my 2020 F-150 several times before, so here's another one. As most know, the Roush supercharger has a charge temp problem that severely constrains power when octane limited, but isn't such a limit on E85. I installed a smaller pulley to raise the boost up and take advantage of E85, which works against me on gasoline. I had already turned on flex fuel in the truck and have spark timing increase or decrease with learned ethanol. Now, I added a load limit that also floats up and down with learned ethanol. Just to prove it out, I set a load limit of 1.0 under 50% ethanol, ramping up to no limit at 60%. The following snips are from one continuous log just after switching from gasoline to E85:
This is immediately after a fill-up with E85. At this time, gasoline is still being delivered to the engine because the fuel system was not yet purged of the olf fuel. You can see that the AFR status was actively learning, triggered on by the fill-up. Pedal is to the floor, desired load is 1.00, and actual load is 1.025, following the gasoline load limit applied. Boost pressure is about 2.5 psi.
I have it set up to add 8 deg of borderline timing between 50 and 60% ethanol:
Here you can see the ethanol learning increasing from 55 to 60% and the borderline timing increasing with it. This is the timeframe over which the flex fuel load limit is also released.
This is 12 minutes after the first snip, in the same continuous log. It didn't quite hit the 60%, but it was close enough to allow the throttle to fully open and the load went past 1.6, boost being about 13 psi. The desired load was lower than actual because only torque demand was setting the desired load, and some other settings in the logic will still push the blade open if driver demand is limiting desired load.
So for everyone looking to get the most out of their flex-fuel supercharged mustang, just know this is possible just by turning on and tuning the stock logic. You can pulley down as far as you want on E85 and set up a load limit on gasoline, which will limit boost as a result.
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