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straight e85 frs tuning

Flex Fuel Tuning

Discussion and questions related to the course Flex Fuel Tuning


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hi

i have a flexfuel sensor and a tune for it, but i want to learn to make my own tune now because i dont own the racerom version of ecutek i cant make my own sensor scaling so i want to learn to make straight e85 tune.

i changed the port injector scaling from 228 to 161 which is what the hpa spreedsheet recommend, it wasnt enough it idled at 17 for about a minute or two and the car died and somehow i bricked the ecu i then retuned the ecu manually.

so i read online that i have to scale the direct injectors too i add 40% to di quantity fuel pressure compensation 1 and 2 it idled better but wasnt rich enough at cruise and the fuel trim wasnt happy at all +and- 10-20%.

then i add 40% to direct injector flow compensation and this got me the best result but way to rich my fuel trim was more than -10% so i thought i should try getting the di quantity fuel pressure compensation back to stock and see if that will get me closer but it was leaner than target and there was hesitation in throttle.

as you can tell im not sure what is right approach is to tune straight e85 and im not sure if 40% more fuel is right for california pump e85, some people online use port injector scaling at 171 instead of 161.

Wait hold on. What's the goal here?

What's wrong with the tune you have already and why do you want to change it? It's not clear from your explanation.

the goal is that i just want to learn to make my own e85 tune nothing really wrong with the tune i have,

i went back to 100% stock tune and 91 octane with e10 California gas and my car is running at 14.7 at wot, im not really sure what is the issue but im guessing its fuel injector or fuel pump issue

With the FRS you have port and direct injectors so as you've found, you'll need to adjust the scaling for both if you want to tune for dedicated E85. This actually requires you to set up the tune to solely use the DI injectors first so you can scale these without any influence from the port injectors. Once the DI injectors are scaled correctly for E85 you can then bring in the port injectors and repeat the process. The worrying thing is that you've mentioned that on normal pump gas with the stock tune you're running 14.7:1 AFR under WOT. This suggests you've got a problem somewhere in the tune or mechanically in the setup. I'd want to make sure the engine is running correctly in stock form on normal pump gas before you even consider an E85 tune.