What is the afr for a E50 blend of fuel? I would like to use this blend in my engine.

That is uncharted fuel

I noticed that. I can't find much on the web either. Surely someone knows.

Set your O2 setup to Lambda if it's capable, then it won't matter what fuel. I find .83-.85 usually works for E fuels.

No such luck. Now what do I do?

Why bother with e50? That sounds like alot of work to mix e85 with 93 if perfect portion for that.


Just run e85, enjoy cooler water temps, more power, and cheaper fuel prices.

Blender pump. Does it for you.

I still don't see the benefit. E85 is cheaper, you can buy it at a pump and pump it directly in a car, plus you get all the benefits of an alcohol based fuel.

Not much cheaper, 5 cents, but is cheaper. E50 comes from the same pump as E85, hence the blender pump, and pump it directly into your car. About the same octane as e85.

I wouldn't waste my time on trying to learn how to tune that, how can less alcholol content have the same octane, or almost as much octane as E85 I run straight pump E85 in my high compression(14.5 to 1 ) bracket motor If E98 was availble locally I would race with that

The AFR for E50 is 11.9. Max power would be AFR 10.2

I agree it's easier to use Lambda, but for initial settings you may need the AFR for calculations.

Here is complete info for you:

Octane is irrelevant with ethanol based fuel.

Why is that?

Lets say you run E-50 fuel, what adjustments, IFR, IAB, MAB, boosters, or any other drilling needing to make it work?

You can't use those numbers unless the AFR gauge is calibrated for the stoich of the fuel. In other words a gas scaled AFR gauge is calibrated for 14.7 as stoich for the fuel. The easiest way to use a gas gauge is to divide the observed number on the gauge by 14.7, that will give you the Lambda number. On a gas scale shoot for 12.2-12.5 as a starting point, jet for best performance from there.

Mark,
12.2-12.5 is for max power right? What would be used for idle and cruise?
Ed

x2. If you're using a wideband that can't be set to lambda, it's likely that a/f ratio can't be set for different stoich points either, so you'll be stuck using the gasoline scale.

The Lambda sensor measures the contents of the exhaust gases and when the combustion is optimal all oxygen is used in the combustion process. This is Lambda=1. Then for those people who want to use the old AFR value, you have to program in the stoiciometric value for your type of fuel. Based on the Lambda value measured, the AFR value is then computed based on the stoiciometric value programmed, and displayed if so chosen.
A Lambda sensor (AFR gauge) is calibrated in free air, not with any relation to the fuel type used.

Pump gas was sooooo easy for me but now with alcohol I'm still trying to learn it. I ran (2) 6.10@112mph yesterday and a 9.66 and 9.65@137mph after leaning out my alcohol 850 carb from 154 jets to 150 jets. My racepak is switched over to the alcohol scale and I'm STILL reading 4.90-5.10 on the O2 reading during a pass. Hard to believe I'm still rich.

Jet and tune for max MPH in the 1/4 mile, correct? The spark plug and time slip will tell you what your combination likes and wants