I realize there isn't going to be much of a gain in power from e85, but I'm going to give it a try anyway. I already need bigger injectors, since I'm running my OEM injectors past 90% duty cycle. I found a good deal on some Siemens Deka 675 cc's so I figure there's nothing to loose in trying out e85.

I think my current FlashPro tune is about as perfect as it could ever be for my current build with 93 octane fuel. My plan is to install the new injectors, then tweak the injector size and opening times in my FlashPro calibration until it's running right with 93 octane again. Then I'm hoping I can just increase my fuel values by some percentage (+33%?) to have a decent starting calibration for e85. I imagine I would need to do this for the cranking fuel too.

Would this be sufficient for part throttle operation? Would I need to make any changes to the lambda tables?

 

i've done a few e85 maps on flashpro but they've all been on 8th gen civic si's lol.

as far as a good starting point. try adding 30% across the boards on the low and high cam fuel map. and like you said dial in the dead times first if you don't have them.

if you don't have the dead times, what i would do is get it to idle ok and then start adding electrical load and start playing with the dead times. it's all trial and error.

as far as the cranking fuel goes add fuel to columns 4 and 5 in the cranking fuel table.

just a heads up, for full throttle tuning aim richer than what you normally would with 93 octane. i usually aim for 12.5 on the street. verify on the dyno. i've had them run as rich as 12.4 but that was with a sniffer widband so i'm sure it's more like 12.5-12.6. it's all trial and error.

hop on the dyno and dial in the afr's as well and the ignition timing maps.

 

Thanks for the info. However, I thought you were supposed to run much richer than that with e85. I thought stoich for e85 was below 10:1.

 

Oh, wait I guess the difference is that the sensor would be reporting the AFR in gasoline terms. So when the e85 is burning at stoich (~10:1), the OEM O2 sensor will report 14.7:1, right?

 

yes we're working with widebands that read in gasoline afr's. theoretically stoich for e85 is around 9.7.

and yes the oem sensor will report 14.7 but it's actually targeting ~9.7.

 

any luck with this gernby?

 

Will the fuel system handle this? Aren't the seals designed for gasoline only?

 

I haven't tried e85 yet, since I just installed the new injectors last Sunday. Now that it is retuned with the larger injectors on pump gas, I may try e85 when the tank is empty again.

The fuel system seems to work fine with e85 for the FI guys that run it.

 

I just made the switch to E85, and it was pretty easy. I just used live tuning to adjust the fuel maps while the engine was idling at the fuel pump after filling it up with E85. The STrim value was low, then it slowly, slowly, slowly rose, then I made a 30% increase to both fuel tables.

Then I drove at part throttle for a few miles, and adjusted the tables until STrim was close to 0. Then I did some full throttle datalogs, which show a tentative 5 ft-lbs gain in torque without any timing adjustments. I'll do more testing tomorrow.

 

You should be able to go crazy with the timing on e85, great power to be had.