Need some e85 knowledge
I literally logged on just to see about this myself. My dad just bought a new silverado with flex fuel and I think it is really neat. I was just curious if it was possible/worth retrofitting a flex fuel setup on a stock LS1.
From what I can gather I think it is only possible via separate tunes and only one fuel type. So technically no flex fuel, but either straight gas or ethanol or a custom tune for a blend.
depends what kind of compression you have, power levels, fuel system, do you have tuning software?
It is most definately worth it if you are building a wild motor or want that last bit of power
It is most definately worth it if you are building a wild motor or want that last bit of power
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TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
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.
Staging Lane
Joined: Sep 2010
Posts: 84
Likes: 0
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.