General Running E85/91 Octane in a tuned for 91 setup: Pro/Cons?

[Ben W]

Hello,

I have a 99 Eclipse currently tuned for running 91 Octane. Everything included, she dyno'd at about 380HP
550 CC Fuel Injectors
EVO III 16 big turbo at around 28 pounds of boost

Anyways, I am JUST outside of emissions for my state, and my mechanic suggested running a mix of E85 and regular gas since E85 runs cleaner.

My question is, is there any reason to do this/not to do this regularly?

Ive heard E85 can help clean an engine out a bit, can provide more power, etc. Of course, all with an appropriate tune

But does mixing allow for a "best of both worlds"?

Thanks for any advice!

 

[Justin DuBois]

I’m running an easy mix of 91oct (E10) + E85.
4gal 91 + 1gal E85
The result is 94oct E25

This is great knock protection and, I got about the same result as you did with a Big 16G - 382hp (before rebuild and a better turbine housing)

I’m maxed out on injector duty cycle at the top end, so in order to run more Ethanol, I’d need more than 720cc’s and/or more Fuel Pressure.

Supra Green FP (260lph) with pos supply wire upgrade and 6an supply line from the pump to the hard line and 6an from the fuel filter to the rail.

 

[habitatguy187]

I would mix a little just to pass emissions, maybe up to 30%. But don’t go boosting around like this with those small injectors.