Fast dual wideband e85 conversions
05-22-2014, 06:18 AM
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Fast dual wideband e85 conversions I tried with a post in the tuning section, I guess there are crickets over there. I have the fast unit which I do like, but I can't seem to find the conversion values so that hptuners see's the 9.76 instead of the gasoline scale 14.7. I contacted fast directly and I couldn't seem to get an answer out of them. I'm guessing I'll have to just play with the numbers in the user defined for the wb setting. Any help would be appreciated thanks Pete
05-22-2014, 07:05 AM
#2
WB's use lambda scale. Meaning stoich is 1.0 no matter what fuel you use. The display simply converts that 1.0 to a 14.7 for gas or 9.76 for E85. If you leave it on the gas scale but run E85 the ideal number for cruising is still 14.7(lambda 1.0). The only difference in the tune is that 1.0 will require an extra ~30% fuel.
Now in the tune of the motor in the GM ECU target stoich should be that of the fuel you are using. 14.7 or 9.76.
As an example: If you tune the motor using pure gas, no E10, and have the stoich set at 14.7, assuming tune is spot on, all you have to do to run E85 (fueling wise) is change that stoich number to 9.76. This does nothing for timing obviously unless it's a flex ECU.
Now in the tune of the motor in the GM ECU target stoich should be that of the fuel you are using. 14.7 or 9.76.
As an example: If you tune the motor using pure gas, no E10, and have the stoich set at 14.7, assuming tune is spot on, all you have to do to run E85 (fueling wise) is change that stoich number to 9.76. This does nothing for timing obviously unless it's a flex ECU.
05-22-2014, 08:45 AM
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I understand that 14.7 is stoich for gas and will be the same for tuning e85. When I use my friends afx wb, I use his wideband settings and I am able to use the ve error correction. It will read ex: 14.7 in the wideband, but 9.7 in my hptuners. I'm trying to figure out how to manipulate the numbers in user defined to make my wideband do the same.
