Need some e85 knowledge
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#8
TECH Senior Member
very simply:
the new fuel's stoich AFR has to be edited in the tune (9.7 vs 14.6);
this will now cause more fuel to be injected, so you may need bigger injectors (depending on engine output level)... this requires injector flowrate (and other injector tables) to be edited in the tune; bigger injectors may require a bigger fuel pump;
while you're at it, you might as well get the VE/MAF tables corrected to ensure your PE is correct as commanded... also you may need make PE richer (if it's not already sufficiently rich);
there may be other things to consider also.
the new fuel's stoich AFR has to be edited in the tune (9.7 vs 14.6);
this will now cause more fuel to be injected, so you may need bigger injectors (depending on engine output level)... this requires injector flowrate (and other injector tables) to be edited in the tune; bigger injectors may require a bigger fuel pump;
while you're at it, you might as well get the VE/MAF tables corrected to ensure your PE is correct as commanded... also you may need make PE richer (if it's not already sufficiently rich);
there may be other things to consider also.
#11
with just h/c/i, stock pump will do. 42lb injectors will be fine. For such a simple set-up, e85 wouldn't net you enough to warrent switching (as compared to 93 on a good tune). In warmer temps, the added cylinder cooling from the added fuel will help some. Using a gas-calibrated wideband, I'd aim for ~13.3-13.5afr at WOT, 15.0-15.2 cruise/part. since it has lower thermal efficiency than gasoline, it requires more fuel volume to achieve the same efficiency. It takes a higher temp/longer to ignite, but burns faster and more complete (as well as having a higher relative octane rating), so you can run more timing, boost, compression, leaner afr's.