E85 gas on Viper a good idea or not

[Aevus]

in few days, we will dyno-tune my car with 24% ethanol

I like the idea to control the fuel's octane so I'll use the worst-case-scenario 87 oct w/10% ethanol base, mixed with 3 gallons pure ethanol for each full tank. That makes 24.5% ethanol total (E10 included).


on very hot days, I'll just add a 4th gallon and/or I'll use 91oct as a base fuel.

[T/A KID]

in few days, we will dyno-tune my car with 24% ethanol

I like the idea to control the fuel's octane so I'll use the worst-case-scenario 87 oct w/10% ethanol base, mixed with 3 gallons pure ethanol for each full tank. That makes 24.5% ethanol total (E10 included).

Just get a sensor so it will take the guest work out… once it stabilizes (usually a few minutes of drive time) apply the ratio to the tune, if fuel was in line before it will stay that way with the value

[Aevus]

finally got some data from my new engine and I had too much fuel, even with the added pure ethanol
I'll upload the new tune tomorrow and then I'll head for the dyno tune later this week with exactly the right ethanol % I want to tune it for

unfortunately no baseline to compare with but I can't wait to see the high-RPM numbers on that thing

[Aevus]

Change of plans.

Found a study that shows E40 would be better for power gain and volumetric efficiency.

https://www.researchgate.net/figure/...fig1_282877799

In his video, Jason mentionned that somewhere between 20% and 40% ethanol would be the sweetspot that combines the benefits of gasoline and ethanol (with less of their downsides..)

Now, it seems that E20 is not enough. Look at these graphs

Effect-of-ethanol-blending-on-the-engine-power-at-different-engine-loads.png

Effect-of-ethanol-blending-on-the-volumetric-efficiency-at-different-engine-loads.png


and AFR here as well


Effect-of-ethanol-blending-on-the-air-fuel-ratio-at-different-engine-loads.png

I'm gonna say something on a hunch: maybe 40% is not the optimal content.
(strictly for power gain -the study was actually looking primary at emissions-)

Maybe it's between 35% and 45% that is the real sweetspot, maybe even 30-50%. The answer is probably 42... hehe

bottomline, I'll dyno-tune with +/- 35%. If I ever have time and money to spend again on that experiment, i'll book another day to try and compare with 45-50%...


OR, if I have enough time I can add few gallons of pure ethanol for a 2nd run of the final tune and see how it goes...

[T/A KID]

Shoot for e50, that’s what I’ve witnessed works great and has same anti detonation properties as e85 just requires less fuel.. my FF tunes I usually have all timing in at E50 and above

[Nth Moto]

Shoot for e50, that’s what I’ve witnessed works great and has same anti detonation properties as e85 just requires less fuel.. my FF tunes I usually have all timing in at E50 and above

So at E50, you know what 50% of the fuel is (ethanol), but what about the other 50%? What if that is 40 octane denaturant, or 60, or 80? What if the combination you're calibrating makes enough cylinder pressure that when half of the fuel composition is garbage that the chamber becomes far less stable and now flirts, or enters, dangerous conditions?

My point above is while I understand the sentiment you're stating, I also think it's too vague to blanket that across all engines. I promise you that if we did the same 50% blend table we'd cork motors left and right at our power levels. While that might be a semi-outlier example, it just bolsters that ethanol is far too misunderstood where everyone is fixated on what percentage is ethanol vs what percentage isn't.

Pure ethanol (alcohol) is one of the worlds best cleaners, period. True "pure" ethanol, which [I]very[I] few fuels start from (typically most start with an E98 blendstock which is already denatured with 2% of whatever is cheapest/burnable, IE 40 octane well head, etc) is clean, clear, and stable. I have some on my desk in a mason jar from 8 years ago and it's identical to the day it got put there. When you mix it with typical gasoline blends, which can be a combination of some 2000 odd components, is when the alcohol can scrub clean the fuel it's been mixed with, resulting in a large portion of the "black goo" that people can find when they have poor quality blends. Of course fuel system component compatibility is important, you do need high quality hoses and materials so they don't break down either.

Just some notes in here that I wanted to relay. And yes, I'm an admitted big fan of ethanol.

[T/A KID]

So at E50, you know what 50% of the fuel is (ethanol), but what about the other 50%? What if that is 40 octane denaturant, or 60, or 80? What if the combination you're calibrating makes enough cylinder pressure that when half of the fuel composition is garbage that the chamber becomes far less stable and now flirts, or enters, dangerous conditions?

My point above is while I understand the sentiment you're stating, I also think it's too vague to blanket that across all engines. I promise you that if we did the same 50% blend table we'd cork motors left and right at our power levels. While that might be a semi-outlier example, it just bolsters that ethanol is far too misunderstood where everyone is fixated on what percentage is ethanol vs what percentage isn't.

Pure ethanol (alcohol) is one of the worlds best cleaners, period. True "pure" ethanol, which [I]very[I] few fuels start from (typically most start with an E98 blendstock which is already denatured with 2% of whatever is cheapest/burnable, IE 40 octane well head, etc) is clean, clear, and stable. I have some on my desk in a mason jar from 8 years ago and it's identical to the day it got put there. When you mix it with typical gasoline blends, which can be a combination of some 2000 odd components, is when the alcohol can scrub clean the fuel it's been mixed with, resulting in a large portion of the "black goo" that people can find when they have poor quality blends. Of course fuel system component compatibility is important, you do need high quality hoses and materials so they don't break down either.

Just some notes in here that I wanted to relay. And yes, I'm an admitted big fan of ethanol.

100% valid points and correct. If diluted alcohol with 87 vs 93 would be a difference on the tune up with regards to timing.

For what the OP has I doubt he would gain much of anything with a 91/93 mix with alcohol hitting e50-e85 on his NA engine . I should have been more clear.. and yes high powered boost rigs, I want as much alcohol I can get for safety and simplicity.

Love some e98, have a port injected c7 that’s around 1100 that I run e98 in more port system and 93/e85 in the tank

[Lawineer]

Change of plans.

Found a study that shows E40 would be better for power gain and volumetric efficiency.

https://www.researchgate.net/figure/...fig1_282877799

In his video, Jason mentionned that somewhere between 20% and 40% ethanol would be the sweetspot that combines the benefits of gasoline and ethanol (with less of their downsides..)

Now, it seems that E20 is not enough. Look at these graphs

Effect-of-ethanol-blending-on-the-engine-power-at-different-engine-loads.png

Effect-of-ethanol-blending-on-the-volumetric-efficiency-at-different-engine-loads.png


and AFR here as well


Effect-of-ethanol-blending-on-the-air-fuel-ratio-at-different-engine-loads.png

I'm gonna say something on a hunch: maybe 40% is not the optimal content.
(strictly for power gain -the study was actually looking primary at emissions-)

Maybe it's between 35% and 45% that is the real sweetspot, maybe even 30-50%. The answer is probably 42... hehe

bottomline, I'll dyno-tune with +/- 35%. If I ever have time and money to spend again on that experiment, i'll book another day to try and compare with 45-50%...


OR, if I have enough time I can add few gallons of pure ethanol for a 2nd run of the final tune and see how it goes...

Huh? What are you talking about? What are those charts talking about? Are you trying to reduce greenhouse emissions?

That article sounds like a high school kid's book report or something.
Volumetric efficiency has no measurable effect on volumetric efficiency, ESPECIALLY for NA direct injected engines. That's like 40% bump in VE for using ethanol? And 40% more power ugh.... no. They're clearly cranking up the boost.

What car injects fuel into the intake manifold these days?
" A fuel with a higher-octane level can endure a higher compression ratio before exploding..." Exploding? You mean detonation?

[Aevus]

If you don't change your timing, imo, there will be no difference. Maybe rich....?

ok so the ethanol helped my idle.

in fact, my tune was too rich and by adding the right amount of pure ethanol I obviously ''fixed'' the AFR.

https://driveviper.com/forums/thread...l=1#post470312

Very happy because it means I can drive the car to the dyno for the real tune.

Undecided yet about the % I'll use for the tune. The ethanol supplier I found locally cannot garantee the purity, says it can be anywhere from 95 to 98% but sure not 99.5 or 99.9%

maybe I'd be safer with a lower % mix in my car

[Aevus]

Lawineer, I have no idea, I found that article by searching for ethanol yesterday. I didnt download the full article

[T/A KID]

ok so the ethanol helped my idle.

in fact, my tune was too rich and by adding the right amount of pure ethanol I obviously ''fixed'' the AFR.

https://driveviper.com/forums/thread...l=1#post470312

Very happy because it means I can drive the car to the dyno for the real tune.

Undecided yet about the % I'll use for the tune. The ethanol supplier I found locally cannot garantee the purity, says it can be anywhere from 95 to 98% but sure not 99.5 or 99.9%

maybe I'd be safer with a lower % mix in my car

Is the tune being adjusted for this??? You can’t just watch the WB and look for differences there… whoever has to tune this needs to know alcohol content otherwise it will never be right..

[T/A KID]

If anything get one of these, hook it up online with fuel line using a GM sensor and use you phone to trace alcohol percent.. (this is what I use on my Gen 5)

https://fuel-it.com/products/fuel-it...-fuel-analyzer

[Old School]

If anything get one of these, hook it up online with fuel line using a GM sensor and use you phone to trace alcohol percent.. (this is what I use on my Gen 5)

https://fuel-it.com/products/fuel-it...-fuel-analyzer

This seems like a must have if you're going to "roll you own" fuel.

[T/A KID]

This seems like a must have if you're going to "roll you own" fuel.

No other way to make it 100% right..
Could use a test tube, but I’d rather use the sensor

[Aevus]

Flexfluel is the longterm solution, but first for the next few weeks i'll compare my pump fuel tune V.S. the E30 tune

https://driveviper.com/forums/thread...l=1#post470376

[Aevus]

its not very sciency but my butt dyno likes the E30 version of my car better. Starts and runs smoother. The top end seems better too

[Aevus]

Article about E30

https://ethanolproducer.com/articles...-quest-for-e30


Article about E40

https://www.enginelabs.com/engine-te...inner-crowned/

[Nth Moto]

Article about E30

https://ethanolproducer.com/articles...-quest-for-e30


Article about E40

https://www.enginelabs.com/engine-te...inner-crowned/

I appreciate your appetite for information and your diligence in seeking it out, but you're going to get your brain cooked with bad information on this topic unfortunately. I typically give Engine Labs a bit more credit than others, but a great example is that article stopped being meaningful to me when I read "E40 from the pump". Legally, nationwide, fuel can not be sold by a retailer from a pump labeled "E85" unless it falls between the range of 51%-83%. Period. Doing so makes them liable for extreme fines. Does that mean it never happens? Surely not, but trust that the risk/reward meter for those stations is high if they let their tank supply run amuck with out-of-spec fuel.

And furthermore, unless I missed it, it never specified how they were measuring said content level. The "beaker style" shake tests have a +/- accuracy range of as much as 10%, and then there is human error opportunity on top of that. So back to what T/A Kid said, a content sensor device is really the only way to fly on this stuff.

Anyways - I'm happy to see a technical discussion on this board and happy to try to interject where I can find some time on topics that we have great depth with, but I'm just giving you fair warning to take all the data you're combing through at face value and understand there are inaccuracies; intentional or not.

[Aevus]

I appreciate your appetite for information and your diligence in seeking it out, but you're going to get your brain cooked with bad information on this topic unfortunately. I typically give Engine Labs a bit more credit than others, but a great example is that article stopped being meaningful to me when I read "E40 from the pump". Legally, nationwide, fuel can not be sold by a retailer from a pump labeled "E85" unless it falls between the range of 51%-83%. Period. Doing so makes them liable for extreme fines. Does that mean it never happens? Surely not, but trust that the risk/reward meter for those stations is high if they let their tank supply run amuck with out-of-spec fuel.

And furthermore, unless I missed it, it never specified how they were measuring said content level. The "beaker style" shake tests have a +/- accuracy range of as much as 10%, and then there is human error opportunity on top of that. So back to what T/A Kid said, a content sensor device is really the only way to fly on this stuff.

Anyways - I'm happy to see a technical discussion on this board and happy to try to interject where I can find some time on topics that we have great depth with, but I'm just giving you fair warning to take all the data you're combing through at face value and understand there are inaccuracies; intentional or not.

Thanks, and I sure appreciate the fair warning.

I'm very interested about the Flexfuel solution, but first I'd like to test if there's any real benefits on my N/A engine...

so, meanwhile, the solution I found (and because I live in Canada, where E85 is very difficult to get anyway) is to mix myself pure ethanol and control the mix the best I can.

For now, I run a E30 tune.
Very practical: just have to add 10 liters (small 2.5 gallons jar) to 33 liters E10-91 (in Canada content varies from 5 to 10%) so in worst case scenario I'll run a little bit richer... Also, a total of 43 liters (out of 70l capacity in my '05) is easy to manage... I don't have to wait until the tank is nearly empty, and 43 liters is enough for a while.

[Aevus]

I appreciate your appetite for information and your diligence in seeking it out, but you're going to get your brain cooked with bad information on this topic unfortunately.

is that one a brain-cookin' recipe as well?

https://www.iea-amf.org/content/fuel...nol_properties

[Aevus]

I felt like a chemist for the last two days. The Walter White of ethanol

So I've been testing that E30 tune, going as low as E15 blend and as high as E40 (DIY).

I think I added about 20 times of either gasoline or ethanol, just to experiment. Was kind of funny to buy only 1 gallon at a gas station... with a Viper.

Yeah, probably no turning back to that. Just the smell (I have a roadster) and the overall smoothness of the idle and throttle makes me love the stuff. Even without any HP gain, I'd do it. The only thing that could stop me is all the corrosion thing that we hear... We'll see.

Now, performance-wise, I think starting E30-E35 it starts to kick in. At E40 I was running too lean to see an improvement, but weirdly enough I felt the potential. So I may try another tune E40 or E45. Probably won't exceed that, because it's a lot of ethanol jars to keep in the trunk each time you go somewhere... But I'll end up somewhere between E30-E45, for sure.

Also I like the fact that it takes +/- 5% differencial without a problem. If you know your car, you'll feel it but nothing dramatic even though the AFR is off.

Of course, in doubt I'll add gasoline so it's richer...

Finally, I had 29 timing @ WOT on pump gas 94 oct, and now that E30 tune is 31 timing @ WOT, but I think I could pull back to 30.


Edit: I clearly wouldnt do it without a Flexfuel kit If I were to buy ethanol blends at gas station (and not knowing the exact %) but in Canada, that's not an option anyway...

[bullitt2735]

just a note that you can't even trust the flex fuel sensor itself fully. E85 sensors don't actually measure ethanol but rather I believe capacitance on the sensor it flows through which translates 0-5v on most setups. So for example if your Ethanol has been sitting and pulled in some water it can through off what the content is. That being said I've never had a sensor off by enough to make me nervous personally and than again when I did have e85 on one of my cars I was NOT buying it at the pump but by the barrel.

[T/A KID]

just a note that you can't even trust the flex fuel sensor itself fully. E85 sensors don't actually measure ethanol but rather I believe capacitance on the sensor it flows through which translates 0-5v on most setups. So for example if your Ethanol has been sitting and pulled in some water it can through off what the content is. That being said I've never had a sensor off by enough to make me nervous personally and than again when I did have e85 on one of my cars I was NOT buying it at the pump but by the barrel.

If water is in the system alcohol sensor will typically read 100! Then you know you have a problem

[chiromikey]

Are you guys monitoring your fuel pumps? I wouldn’t think most OEM fuel systems could comfortably handle more than E25-E30.

[chiromikey]

…The "beaker style" shake tests have a +/- accuracy range of as much as 10%, and then there is human error opportunity on top of that. So back to what T/A Kid said, a content sensor device is really the only way to fly on this stuff...

I’ve been looking for this information for a while so if you could share a link I’d appreciate it. I’m so tired of guys that failed high school chemistry and are too dumb not to forget their test tubes sitting on top of the pump after filling up telling me that my sensor isn’t accurate. Weird how my sensor is supposedly so inaccurate but it hasn’t blown up an 1100hp motor that absolutely relies on it to run the appropriate maps.