I've seen pretty much everyone has been running E85 around 11.5 AFR on a gas wideband, and seen some posts of running leaner. Has anyone tried running it at 10.5? I know ethanol has a pretty big window, so maybe it doesnt make a difference. Just wondering if anyone has found more power going richer.

 

As a general rule of thumb lean makes more power.

 

What's lean with E85 on a gas-wideband?

 

E85 is similar to 110 octane. On a regular wideband reading in gas scale, 12.0 to 1 is on the lean side of safe, and 11.0 to 1 is on the rich side of safe. EGT's are colder vs. gas, so it can be run towards the lean side as long as your timing and boost aren't sky high.

 

I guess I should have asked what do the "Max Power Lean" and "Max Power Rich" numbers mean for a fuel? Does the window in between them all make the same power, or is there more power at those two spots?

I think I've figured it out since I posted though. Looks like it's a window where the power is within 1% of max possible. Outside of it you lose power, and on gas it's 12.5-13.2, but turbo engines cant run in that range, so you run as lean as possible to get close to it. The range for E85 is 10.5-12.7, and we can run comfortably in there, theres no reason to go to the richer side of it.

Am I close?

 

What i'm wondering is if the leaner E85 burns faster to an extent where you can actually make more power by running it leaner. Because i'm on the same page with you where max rich and lean window for E85 is a lot wider than gasoline's and therefore theoretically you shouldn't lose any power even if you run 10.5 as opposed to, say, high 11's. You're just adding a safety margin and more cooling, which is good.
Unless, again, it slows the burn rate by a significant amount... But i kinda doubt that..

 

I Just Got My Car Tuned With E85. Making 375whp/365lbs Tq. charts

 

In my experience, leaner made more power just like regular gas. rich is not a good idea with E85, your gas mileage suffers too much and you will have ignition problems(misfires) with so much fuel dumping into the cylinders.

 

You probably have a good point about making more power at leaner afr's, Lucas' car is probably the prime example, making 500whp..
But I have seen as low as 10.7 on my car and i had no ignition problems (not saying i run it all the time). Also in my opinion it's better to adjust cruise AFR's and go WOT less if you're after better mileage. Saving money by leaning out WOT afr is a bit risky.

 

I have ran 13.0-10.0 I start getting in the 10s and you can tell you are losing power. On my 500whp runs I was 10.2 out the top. Did not have much time to play with the tune but I bet 5-10hp getting my AFRS back into the high 11s. I was at 12.2 at my peak HP #.

 

Lemme just bump this ...

I just did some math based on the stoichiometry of Ethanol and Gasoline. My math shows that 1.0 lambda would be 9.85:1 on E85 (calculated as 85% ethanol and 15% gasoline). That would put the ideal AFR at ~8.3:1 to ~8.6:1 (~.84 to ~.87 lambda).

Is this math correct or am I missing something completely? Are you guys using gasoline calibrated WBO2s for the numbers posted here?

 

Yes they are talking about Gasoline calibrated WB.

Mitch