93 v E30 v. E85

[ZXMustang]

I’m saying that e50-60 is about all the octane you need to reach MBT for your engine in its current state. You can use the same spark at e50 that you’d use at e85 and the car isn’t going to pick up. Now there will be a slight cooling advantage with more E but we are taking about margin of error in terms of measured gains.

You won’t actually see knock retard on E85. The car will just make less power with the more spark you add past what the car already wanted. It’s not like pump gas where you add spark until you pick up knock and then dial it back 1 to 2°. Some people get in the trap, thinking that since they’re not seeing knocked that the car is making more power with the more timing they add, and that’s not true with the E85.

I retuned a car a few weeks ago that had 36° of timing being added on E85. The guy was mad. It wasn’t doing the 60 to 130 that he wanted or expected. I pulled it down to 30° and the car went almost a second faster.

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[ZXMustang]

So does the stock tune on E30 adjust the OEM stoich point, or does the engine just run lean?

Neither. The car does not adjust the stoich point nor does it run lean because you have wide bands. The widebands just pick up the slack and add the extra 8 to 10% of fuel that you need. This is also why you don’t wanna do this with E40, because it’s a lot bigger volume deficit that the fuel trims need to fix. And if there’s a hiccup or a problem, you don’t want the car to be adding 20% fuel at any given moment in a wide open pull.

 

[Junkyard Dog]

You won’t actually see knock retard on E85.

Interesting.

Thank you for answering my questions. This has been helpful.

 

[ZXMustang]

Interesting.

Thank you for answering my questions. This has been helpful.

I should qualify that statement you quoted. You will get knock on E85 if you put enough spark in it, but we are talking a tremendous amount over MBT where the car is happy. But still far enough above MBT where you might think the car still want it.

Example. Average NA coyote likes anywhere from 30-32* of spark on full E85. It might like 33* or even 34*(RARE), but you could put 36-38* in it and it will still look like its happy on paper in logs, but it sure wont be. But the octane is so high, the car will just make less power and be slower.

Now if you decided to push it until you saw knock, then you might get 40*+ into it before you see a hint of knock. Luckily its well known where the limits are for just about any unopened coyote from 2011-present.

So yes you can see KR, but only if you push it way past MBT trying to find the limits. Which nobody is doing, not since 2011... At least I hope.

And as I said, most NA cars want 30-32. thats the safe sweet spot.

And for you being a track guy, You could easily JUST change the stoich point from 14.08 to 9.80 on your stock tune, make some cooling changes to the grille shutters if you have them and the ECT Rad fan settings and just run full E for track days. That would take your engine heat problem and cut it way down. The intake charge cooling advantage from e10 93to E85 is quite a lot. Without adding any spark, you are getting a massive octane bump for the OEM spark architecture as well as that massive cooling addition on top.

Your gas miles will be dogshit lol. On track it would probably be 4-10mpg depending on how hard you push it.

 

[robvas]

SO what is the formula for E30 by mixing? is 11gals of 93 and 5 of E85? I believe I saw a YouTube video on it....cannot remember

"It depends"

Is your pump gas E10 or E15?

Is your 'E85' E85, E70, E50...??

Easiest way is to make a little spreadsheet.

Formula for a full tank would be something like:

=((GAS*10)+(E*85))/16

Meaning:

((Number of gallons of GAS * ethanol content) + (number of gallons of E85 * ethanol content))

Then, divide that by the total number of gallons of GAS + E85 you are putting in

For true E85 and E10 93, it's about 1:3 ratio

So, if you were going to add 12 gallons of fuel (let's say you have 1/4 tank of gas left)

You'd put in 3 gallons of e85 and 9 gallons of 93

That's assuming you had a E30-ish mix in the rest of the 4 gallons in that 1/4 tank you have left. And if you're starting with a 1/4 tank of pure 93, use 4 gallons of E85 then the rest of the tank (8 gallons) 93

Assumming a 16 gallon tank. Can AI be trusted? 20th generation Mustang? Here's another for my 'AI goofs' collection...

 

[cbrtrx]

"It depends"

Is your pump gas E10 or E15?

Is your 'E85' E85, E70, E50...??

Easiest way is to make a little spreadsheet.

Formula for a full tank would be something like:

=((GAS*10)+(E*85))/16

Meaning:

((Number of gallons of GAS * ethanol content) + (number of gallons of E85 * ethanol content))

Then, divide that by the total number of gallons of GAS + E85 you are putting in

For true E85 and E10 93, it's about 1:3 ratio

So, if you were going to add 12 gallons of fuel (let's say you have 1/4 tank of gas left)

You'd put in 3 gallons of e85 and 9 gallons of 93

That's assuming you had a E30-ish mix in the rest of the 4 gallons in that 1/4 tank you have left. And if you're starting with a 1/4 tank of pure 93, use 4 gallons of E85 then the rest of the tank (8 gallons) 93

Assumming a 16 gallon tank. Can AI be trusted? 20th generation Mustang? Here's another for my 'AI goofs' collection...

Yeah AI is funny. This gen mustang still has the 16 gallon tank.

 

[ZXMustang]

I just use the e85cal app on iphone. Lets you change everything as needed to account for any variance in E content, tank size, volume left in the tank and so on. Easy to pull out the app at the pump, move some sliders and go.

 

[robvas]

They should make gas pumps like Coke Freestyle machines

Choose your own mix, add boostane or Techron...

 

[ZXMustang]

They should make gas pumps like Coke Freestyle machines

Choose your own mix, add boostane or Techron...

lol that would actually be pretty cool.

 

[Junkyard Dog]

Is your 'E85' E85, E70, E50...??

variance in E content

What are the options for determining the ethanol percentage?

 

[Q6543]

Check facebook, I’m in Michigan and we have a group that consistently tests and posts stations.
Makes it way easier using a group effort like that.

I never even see bad readings around here, even the “winter blend” tests high 70s to low 80s

it’s not for everyone, hell just run 260GT or some other local unleaded pump race fuel

 

[cbrtrx]

What are the options for determining the ethanol percentage?

Fuel-it makes a Bluetooth inline ethanol sensor kit.

 

[ZXMustang]

Yeah FF sensor to an app on your phone or you can buy the cheap tester on amazon and test it at the pump.

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