Running FiST with E85 Blends - Discussion Thread

[Brickell FIST]

You’re making a great case for upgrading the turbo. You lose the crazy torque and gain horsepower win win. Hybrid is far superior over the stock turbo. Night and day and the car should have came like that. Less spinning and pulls to the redline. Why spin the tires down low and run out power 5k is beyond me..

 

[TyphoonFiST]

Hey I never even sniffed 91 my whole life until I was out here in the vast middle. But oh boy I will always have a 91 tune guaranteed you betcha! Unicorn shit will soon be banned so edit your gif you monster [emoji108]

It's a Llama silly

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[MRX330]

It's a Llama silly

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UniLlama ding dong! 🖖

 

[danbfree]

You’re making a great case for upgrading the turbo. You lose the crazy torque and gain horsepower win win. Hybrid is far superior over the stock turbo. Night and day and the car should have came like that. Less spinning and pulls to the redline. Why spin the tires down low and run out power 5k is beyond me..

Hybrids also spool 98% as quick as stock with even a little more torque. And who said anything about spinning the tires? You also gotta upgrade your mounts, and not just the RMM and call it good. I don't do launches either so wheel spin is nearly a non issue even with factory all seasons, and will be completely a non-issue once I get sticky 215's on. I'm also hitting max HP at a 5500RPM with still over 200whp at 6500RPM. So honestly not sure what you're talking about unless you are just exaggerating or have never run a proper ethanol tune. Either way, y'all are starting to go off-topic, this isn't a thread of why you should go with a bigger turbo it's supposed to be about ethanol tuning.

 

[danbfree]

Ethanol blends are reported “leaner” because they have a different stoichometry than gasoline.

Sure, but I'm only losing 10% of the mileage while more than tripling the amount of ethanol. Because of all the anti-knock properties and cooling charge of ethanol, it still is ran leaner.

 

[Hijinx]

Sure, but I'm only losing 10% of the mileage while more than tripling the amount of ethanol. Because of all the anti-knock properties and cooling charge of ethanol, it still is ran leaner.

That’s not how the AFR works. Stoich for E30 is roughly 12.99. At that value, Lambda is 1. In turn, the car reports via AP 14.7. Your car is calibrated to turn lambda values into gasoline AFR.

To further clarify this point, a value of 11.x on E30 is equivalent to 0.8x lambda. 0.8x lambda on gasoline is about 12.x on gasoline. So, you’re not necessarily running leaner... This is a misconception a lot of people have because they only go by what they see on the AP. Your car does not use AFR, it only reports it. The car uses lambda which the tuner is targeting.

It’s not magic, either. This knowledge is very accessible. If look for fuel stoichometry numbers and the lambda equivalency ratio you can confirm what I’ve said.

 

[danbfree]

That’s not how the AFR works. Stoich for E30 is roughly 12.99. At that value, Lambda is 1. In turn, the car reports via AP 14.7. Your car is calibrated to turn lambda values into gasoline AFR.

To further clarify this point, a value of 11.x on E30 is equivalent to 0.8x lambda. 0.8x lambda on gasoline is about 12.x on gasoline. So, you’re not necessarily running leaner... This is a misconception a lot of people have because they only go by what they see on the AP. Your car does not use AFR, it only reports it. The car uses lambda which the tuner is targeting.

It’s not magic, either. This knowledge is very accessible. If look for fuel stoichometry numbers and the lambda equivalency ratio you can confirm what I’ve said.

I understand, so let me ask this: if ethanol contains 30% less energy by volume, then why do I only get about 10% less mileage even when I quadruple the amount of ethanol used? I figured there has to be some ability to tune at least a bit leaner with its anti-knock properties with less volume.

 

[Hijinx]

I understand, so let me ask this: if ethanol contains 30% less energy by volume, then why do I only get about 10% less mileage even when I quadruple the amount of ethanol used? I figured there has to be some ability to tune at least a bit leaner with its anti-knock properties with less volume.

Another misconception: E100 contains ~30% less energy than gasoline. E10 contains about 1% less energy than gasoline.

We can confirm this with the BTU values. E100 is 76,330 btu/gal. E10 is 112,114 btu/gal.

E100/E10 = 69%. In other words, E100 has 31% less energy content than E10. We can do a simple conversion for E30.

Gasoline is 115,000 btu/gal, so 1%.

I don’t have time to work out the energy content of E30, but I would assume it’s probably 3-4% less than gasoline. Without continuing, I’m guessing you can see the answer to your question at this point. On top of all of that, you really only see a big difference in consumption when you’re WOT.

 

[MRX330]

Please for the love of all things good in this world will all sane people please stop posting here? Nothing good can come of this. Judas Priest my eyes! 👁👁

 

[danbfree]

Another misconception: E100 contains ~30% less energy than gasoline. E10 contains about 1% less energy than gasoline.

We can confirm this with the BTU values. E100 is 76,330 btu/gal. E10 is 112,114 btu/gal.

E100/E10 = 69%. In other words, E100 has 31% less energy content than E10. We can do a simple conversion for E30.

Gasoline is 115,000 btu/gal, so 1%.

I don’t have time to work out the energy content of E30, but I would assume it’s probably 3-4% less than gasoline. Without continuing, I’m guessing you can see the answer to your question at this point. On top of all of that, you really only see a big difference in consumption when you’re WOT.

Hey, thanks, this makes sense and I appreciate you taking the time to explain! I think the difference comes out closer to that 10% difference so it does makes total sense.. It's also nice to see like zero knock and zero negative corrections while making massive power, so I'm really sold on using ethanol blends, you just have to make sure to burn through a tank every couple of weeks to avoid issues with how it attracts water over time.

 

[TalkToTheFiST]

I have a question if anybody has an answer. I am running an e30 tune and tested the pumps closest to my house (9m drive). E85 showed 84% and the 91 gas showed up as 5%. Calculating for a 12.39g tank, i needed 3.92g of E85 and the rest 91. So my first e30 fillup was a couple days ago and i went 4 gallons of E85 and the rest 91. So today i was in the neighborhood of that station so i topped off just over a quarter tank, doing the math for both.

My AP said i was at 68%, so i calculated in 32% to my e30 app. To make sure the app was correct i did the math myself, 4 x 0.32 and got 1.28 gallons of E85 and the rest 91. Now with a 12.4g tank, and filling up about 4g per tank of E85, that leaves about 8.4g of 91 per tank, so the ratio is close to 2:1 any time i fill up.

So i filled in 1.28g of E85 exactly but when i topped off with the 91, just over 4 gallons fit, so what gives? Is the AP guessing the tank capacity based on exactly 12.4g and the actual tank is a bit bigger? Are APs just not accurate with tank percentages? Next time i will probly just have the figures for both which would have been about 2.7g of the 91 but i'd like to get that extra 1.5g so i don't have to stop as often.

Anybody else have an experience like this or have a solution? The only two things i can think of are, only fill in the amounts shown in the calculation for a 12.4g tank, or, add 1/2 gallon o fE85 to whatever the numbers say and then about 1g to what the 91 numbers say, which will roughly give me that extra 1.5g. Ideas?

 

[TyphoonFiST]

Don't over think it....I had the stratified e30 tune and would always put in about 3 gallons of e85 and then the rest 93 0r 91 Oct after you run your tank almost completely empty. It works out to be about perfect mix. If you wanna get super anal get the Fuelit sensor with bluetooth and the App for your Phone its about $299. then use that to find out what is exactly in your tank.

Straight from the Horse's mouth / Stratified......

The correct E85 mixing procedures are as follows:

1. Drive the tank to near empty.

2. Fill the tank with 3 US gallons (12 litres) of E85 fuel.

3. Fill the rest of the tank with premium fuel.

4. Flash the map and enjoy!

 

[TalkToTheFiST]

Don't over think it....I had the stratified e30 tune and would always put in about 3 gallons of e85 and then the rest 93 0r 91 Oct after you run your tank almost completely empty. It works out to be about perfect mix. If you wanna get super anal get the Fuelit sensor with bluetooth and the App for your Phone its about $299. then use that to find out what is exactly in your tank.

Straight from the Horse's mouth / Stratified......

The correct E85 mixing procedures are as follows:

1. Drive the tank to near empty.

2. Fill the tank with 3 US gallons (12 litres) of E85 fuel.

3. Fill the rest of the tank with premium fuel.

4. Flash the map and enjoy!

Yea that's what the guy on the phone at Stratified said when i called. The thing is the percentages matter too. If you had 91 with no ethanol and E85 that was only 51%, 3 gallons would have you greatly under the e30 ratio, which as i understand it would be very dangerous as the car is injecting fuel in quantity based on e30. So you get far more lower octane fuel and at a very high PSI (so far i have got up to 26.8 boost).

So i agree in theory the idea is simple but i wanted to get a ballpark figure first then round it out, which i did to make it simple (4 gallons means 1 gallon for every 1/4 tank). I was just curious if anybody might know a reason the capacity didn't match what the AP told me.

 

[TyphoonFiST]

I dont trust the Ap for anything other than Temperatures of fluids and AFR and knock and also boost. When you get to where I am..... if you ever do.....some of the readings become skewed due to Turbo change. The E85 you have found is pretty good...use it and fill it up with some premo and enjoy!

 

[Erick_V]

The quality of e85 matters to an extent, I’d imagine not so much on a flash tune because they allow some room for lower levels. But a tune where you’re pushing it, would.

For example: I just filled up, I put 4 gallons of e85 (tested out to 72%) and 7.85 gallons of 93 (assuming 10% eth) doing the math my fuel content should be e32. Had I filled with 3 gallons e85/8.85 gallons of 93 it would have been e25. Is 7% a huge difference? No, but I always test my e85 considering it can range from 85 like my old station all the way down to 51. Good to at least know where the levels are and adjust accordingly. The station I use now fluctuates by ~5% so I usually take a little home to test it each time. I doubt it any damage would have occurred with e25, I test it for piece of mind, I’m weird like that.

Long story short put 3 gallons of E and the rest 93 and you’ll be fine. Or be weird like me and test it all the time

 

[CSM]

Long story short put 3 gallons of E and the rest 93 and you’ll be fine. Or be weird like me and test it all the time

pretty much this. I used to test every time but the reality is that my tune accommodates E25-E35. Its somewhat conservative.

In the end always consult your tuner, but know that most flash tunes are fairly conservative and can accommodate a range.

 

[TalkToTheFiST]

The quality of e85 matters to an extent, I’d imagine not so much on a flash tune because they allow some room for lower levels. But a tune where you’re pushing it, would.

For example: I just filled up, I put 4 gallons of e85 (tested out to 72%) and 7.85 gallons of 93 (assuming 10% eth) doing the math my fuel content should be e32. Had I filled with 3 gallons e85/8.85 gallons of 93 it would have been e25. Is 7% a huge difference? No, but I always test my e85 considering it can range from 85 like my old station all the way down to 51. Good to at least know where the levels are and adjust accordingly. The station I use now fluctuates by ~5% so I usually take a little home to test it each time. I doubt it any damage would have occurred with e25, I test it for piece of mind, I’m weird like that.

Long story short put 3 gallons of E and the rest 93 and you’ll be fine. Or be weird like me and test it all the time

Thanks for the example Erick. I guess my logic was, if i had to choose between maybe running too much ethanol or too little, too much would be the better choice. Too little means too low octane and you get excessive knock. Too much means maybe a bit less power but it's still not likely to damage my engine long term.

There are afterall people running e40, and the OP of this thread links the guy running straight e85 with no apparent problems. I just didn't want to go too far the other direction. I probably won't test it all the time but i wanted to get a ballpark to start.

 

[danbfree]

Thanks for the example Erick. I guess my logic was, if i had to choose between maybe running too much ethanol or too little, too much would be the better choice. Too little means too low octane and you get excessive knock. Too much means maybe a bit less power but it's still not likely to damage my engine long term.

There are afterall people running e40, and the OP of this thread links the guy running straight e85 with no apparent problems. I just didn't want to go too far the other direction. I probably won't test it all the time but i wanted to get a ballpark to start.

Too much ethanol *could* eventually lean out if you go over e50, but likely just a bit less mileage with no loss of power if you stick around e35-40.

 

[Hijinx]

I have a question if anybody has an answer. I am running an e30 tune and tested the pumps closest to my house (9m drive). E85 showed 84% and the 91 gas showed up as 5%. Calculating for a 12.39g tank, i needed 3.92g of E85 and the rest 91. So my first e30 fillup was a couple days ago and i went 4 gallons of E85 and the rest 91. So today i was in the neighborhood of that station so i topped off just over a quarter tank, doing the math for both.

My AP said i was at 68%, so i calculated in 32% to my e30 app. To make sure the app was correct i did the math myself, 4 x 0.32 and got 1.28 gallons of E85 and the rest 91. Now with a 12.4g tank, and filling up about 4g per tank of E85, that leaves about 8.4g of 91 per tank, so the ratio is close to 2:1 any time i fill up.

So i filled in 1.28g of E85 exactly but when i topped off with the 91, just over 4 gallons fit, so what gives? Is the AP guessing the tank capacity based on exactly 12.4g and the actual tank is a bit bigger? Are APs just not accurate with tank percentages? Next time i will probly just have the figures for both which would have been about 2.7g of the 91 but i'd like to get that extra 1.5g so i don't have to stop as often.

Anybody else have an experience like this or have a solution? The only two things i can think of are, only fill in the amounts shown in the calculation for a 12.4g tank, or, add 1/2 gallon o fE85 to whatever the numbers say and then about 1g to what the 91 numbers say, which will roughly give me that extra 1.5g. Ideas?

The capacity is 12.4gal but that’s if the tank is dry. 11.2gal is a better number. To be honest, you’ll have a better experience and more accurate tanks if you do not try to top off. Previously, I never went over 10gal of fuel. Run down to 1/4 tank, and put in 6 gal with the appropriate ratio. Might require a sooner trip, but it’s better piece of mind.


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[TalkToTheFiST]

The capacity is 12.4gal but that’s if the tank is dry. 11.2gal is a better number. To be honest, you’ll have a better experience and more accurate tanks if you do not try to top off. Previously, I never went over 10gal of fuel. Run down to 1/4 tank, and put in 6 gal with the appropriate ratio. Might require a sooner trip, but it’s better piece of mind.


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Today i tested it out. I had the AP showing 79%. Calculations showed to get to exactly 12.39g i needed 0.82g of E85 and 1.78g of 91. My theory was the tank is about 1.5g more than what the AP shows, so since my ration is 2:1, i added half a gallon more E85 and checked to see if 91 topped off went 1 gallon over.

Sure enough, i put in 1.32g of E85 and ended up at 2.8g of 91, almost exactly 1g more than what the AP math showed. So from now on i will do everything normally, going off the AP and using my ethanol app to reach e30 and just adding 1/2g of ethanol and 1g of 91, which should be within a few ounces of totally full and still keeps my 2:1 ratio intact.

I haven't yet estimated the total capacity adding everything up but it doesn't really matter, as long as i get the ratio right and get to fill the tank up full. That extra 1.5g means i can drive another 35m or so before i have to fill up again so it's worth it for me.