Cobb OTS stage 1 91 time and E85 mix???

[ruSTy]

Ok totally dumb and newbie question but I need the knowledge of his group. I think I found an E85 station near me. So I want to know if it’s safe to run an E85 and 91 mix on the Cobb stage 1 91 tune? Is there some magic mixture of E85 and 91 that I should use?

 

[Truth in Ruin]

This should help with that question.

http://www.fiestastforum.com/forum/threads/10046-Second-FiST-2016-Fiesta-ST

 

[ruSTy]

Thank you Truth in Ruin

 

[redmoe]

I just recently ran an E30 mix on my stratified 91 tune with no adverse results other than really crappy milage lol. It actually ran really well but the fuel trims were obviously high to compensate for the high ethanol content. You will want to test the flex fuel for the actual ethanol content as AZ switched to E54 in 2016. They may still be some stations getting true E85 but I doubt it.

An E15 mix should be completely safe as even the stock tune can run that. Since we are on the summer blend the ethanol % in 91 is probably closer to 5%. So based on that 2/10 flex with 8/10 91 and you are pretty close to e15. Or an empty tank approx 2.4 gallons of flex and the rest 91 and you are there.

 

[alexrex20]

Just get a Stratified E30 tune. What's peace of mind worth?

Sent from my SM-G950U using Tapatalk

 

[redmoe]

Peace of mind is relative as the e30 tune is much more aggressive and could be damaging if regular e10 was run by accident. On the flip side e30 on an e10 tune is just wasteful but does not pose a significant threat to the engine.

I do agree that if you are going to spend the time mixing fuels you might as well get the most out of it and purchase an e30 tune. Stratified has pretty reasonable prices and a significant amount of r and d time on this platform.

 

[ruSTy]

I intend on getting the Stratified E30 tune, but I want to make sure it’s ok to run that fuel mix until I get my tune. Redmoe I live in Prescott, where do you live in AZ?

 

[redmoe]

I’m in the east valley (queen creek) area.

 

[danbfree]

Surprised no one has said this yet, but you can run 1-1.5 gallons of e85 with the rest 91 and then run the 93 octane (Cobb or whatever) tune... Running e30 is the equivalent of running a 95 octane tune, the ethanol acts as an octane booster so that's what e30 tunes literally do, tune for 95 octane.

 

[redmoe]

Surprised no one has said this yet, but you can run 1-1.5 gallons of e85 with the rest 91 and then run the 93 octane (Cobb or whatever) tune... Running e30 is the equivalent of running a 95 octane tune, the ethanol acts as an octane booster so that's what e30 tunes literally do, tune for 95 octane.

This is not entirely accurate as e30 can vary from approximately 94 to 98 octane depending on the region. Also e30 has a lower energy content than 93. This requires the ecu to raise the fuel trims to match the target lambda value. The afr targets (lambda) will be different between a 91, 93 and e30 tune.

As I stated earlier in this thread you should be fine running e30 on a 91 tune but it is not optimal. Also using ethanol as an octane boost works but you need to keep in mind that running more than say e15 in a regular 91/93 tune will be pushing the fuel trims past the optimal range for that tune and the afr curve in not optimal for the increased ethanol level.

 

[danbfree]

This is not entirely accurate as e30 can vary from approximately 94 to 98 octane depending on the region. Also e30 has a lower energy content than 93. This requires the ecu to raise the fuel trims to match the target lambda value. The afr targets (lambda) will be different between a 91, 93 and e30 tune.

As I stated earlier in this thread you should be fine running e30 on a 91 tune but it is not optimal. Also using ethanol as an octane boost works but you need to keep in mind that running more than say e15 in a regular 91/93 tune will be pushing the fuel trims past the optimal range for that tune and the afr curve in not optimal for the increased ethanol level.

If the octane varies that is because the amount of ethanol is varying from e85, some people get as low as e54 sold as e85, so you should be testing before you pump anyway, but also e30 tunes do provide some flexibility...

But yes, good point about AFR's, I should be clear that the power gains itself comes from higher octane.... but my point stands too, just add a gallon of e85 and the rest 91 and try out the 93 octane tune. Have OAR learn and total ignition corrections set up on your AP and as long as OAR stays in the negative (-0.1 to -1.00 best) and ignition corrections don't show anything past -3.00 negative and mostly positive, then your octane is fine for the tune.

 

[redmoe]

If the octane varies that is because the amount of ethanol is varying from e85, some people get as low as e54 sold as e85, so you should be testing before you pump anyway, but also e30 tunes do provide some flexibility...

But yes, good point about AFR's, I should be clear that the power gains itself comes from higher octane.... but my point stands too, just add a gallon of e85 and the rest 91 and try out the 93 octane tune. Have OAR learn and total ignition corrections set up on your AP and as long as OAR stays in the negative (-0.1 to -1.00 best) and ignition corrections don't show anything past -3.00 negative and mostly positive, then your octane is fine for the tune.

Power gains do not solely come from higher octane levels. Octane is just the measure of the fuels resistance to pre ignition. Octane is in no way an indication of the fuels energy level.

Higher octane allows for higher boost pressure and increased engine timing due to the increased resistance to pre ignition. If you ran pure ethanol you would have a very high octane level (113) you would need approx 33% more to make the same heat energy of gas.

 

[redmoe]

I would not recommend just adding one gallon of flex fuel. Rather do the math based on you remaining fuel % so you have a better idea of where you are at. In AZ once you go e30 it’s just a 50/50 with 91 and you are in the e30 window.

 

[danbfree]

Power gains do not solely come from higher octane levels. Octane is just the measure of the fuels resistance to pre ignition. Octane is in no way an indication of the fuels energy level.

Higher octane allows for higher boost pressure and increased engine timing due to the increased resistance to pre ignition. If you ran pure ethanol you would have a very high octane level (113) you would need approx 33% more to make the same heat energy of gas.

Absolutely, I just oversimplified by saying the octane is what creates more power, because ultimately that's true...You provided the exact details which is always good to know!

But, what I'm also saying is that it is not mentioned enough, is that if you don't want to pay for an e30 tune and just add 1 gallon of e85, it is a safe and easy way to run a 93 tune as well.

 

[redmoe]

I completely agree with watching the oar and ignition corrections. This so be standard practice after each fill up to verify the fuel is good.

 

[redmoe]

Peace. I just like to get the facts out there. Sometimes people will run with general advice and not apply the details to their application which can get them into trouble.

 

[danbfree]

And this was about an easy way to use a regular 93 tune, not for an e30 tune, to be clear.

I would not recommend just adding one gallon of flex fuel. Rather do the math based on you remaining fuel % so you have a better idea of where you are at. In AZ once you go e30 it’s just a 50/50 with 91 and you are in the e30 window.

Sent from my LG-H932 using Tapatalk

 

[danbfree]

I would not recommend just adding one gallon of flex fuel. Rather do the math based on you remaining fuel % so you have a better idea of where you are at. In AZ once you go e30 it’s just a 50/50 with 91 and you are in the e30 window.

So, let's summarize here: I'm just trying to say if you don't feel like paying for an e30 tune and having to test every fillup, that simply adding one gallon of e85 to the rest 91 will allow you to use the 93 octane tunes out there. Those are often cheap/included with an AP, etc... Also, yes, for an e30 tune you are looking at using 50/50 e85 and 91 IF your e85 only tests out as e54, which I hear happens down there in AZ... So while e30 tunes can give you a full step of power above 93, there is also much more involved in paying extra for an e30 tune and literally having to test it at the pump every time. But by simply adding 1 gallon every time you fillup, will bring you up to 93 octane and be in the e15 range that a regular 93 tune can handle. So it's literally another mid-level option instead of just using 91 tunes, or all the involvement with an e30 tune. If after putting 1 gallon in, use a 93 tune and just watch your OAR and ignition corrections. If you set up a 91 and 93 map on separate slots you change on the fly or even stop and reflash off your AP if they separate files, but still easier than doing full e30

 

[Hijinx]

So, let's summarize here: I'm just trying to say if you don't feel like paying for an e30 tune and having to test every fillup, that simply adding one gallon of e85 to the rest 91 will allow you to use the 93 octane tunes out there. Those are often cheap/included with an AP, etc... Also, yes, for an e30 tune you are looking at using 50/50 e85 and 91 IF your e85 only tests out as e54, which I hear happens down there in AZ... So while e30 tunes can give you a full step of power above 93, there is also much more involved in paying extra for an e30 tune and literally having to test it at the pump every time. But by simply adding 1 gallon every time you fillup, will bring you up to 93 octane and be in the e15 range that a regular 93 tune can handle. So it's literally another mid-level option instead of just using 91 tunes, or all the involvement with an e30 tune. If after putting 1 gallon in, use a 93 tune and just watch your OAR and ignition corrections. If you set up a 91 and 93 map on separate slots you change on the fly or even stop and reflash off your AP if they separate files, but still easier than doing full e30

I just want to intervene here and say that you can find your areas E85 blend schedule pretty easily on the Internet. You should only have to test once during a blend season. Furthermore, if you’re on an E30 tune by a reputable tuner, there is built in leeway on the percentages (within reason). For example, (when my car ran) I always put the exact same amount of E85 and 93 in, regardless of what season/blend it was. In my area E85 varies from 50-60 (winter blend) and 70-80 (summer blend). No, fueling is not why my car isn’t running right now. Anyway, if you’re on an E-blend tune, it’s ok to test frequently and adjust but it’s really not needed.

Furthermore, while it’s not harmful to run a single gallon of E85 in your 91/93, you must be careful and avoid getting carried away. Octane is not the only difference between a 91/93 and a E30 tune. You must also consider the amount of fuel being delivered. An E30 tune must deliver more fuel than a 91/93 tune; therefore too much E85 on a 91/93 tune can run into lean conditions as you are not delivering enough fuel for the load/torque targets.


Sent from my iPhone using Tapatalk

 

[alexrex20]

So, let's summarize here: I'm just trying to say if you don't feel like paying for an e30 tune and having to test every fillup, that simply adding one gallon of e85 to the rest 91 will allow you to use the 93 octane tunes out there. Those are often cheap/included with an AP, etc... Also, yes, for an e30 tune you are looking at using 50/50 e85 and 91 IF your e85 only tests out as e54, which I hear happens down there in AZ... So while e30 tunes can give you a full step of power above 93, there is also much more involved in paying extra for an e30 tune and literally having to test it at the pump every time. But by simply adding 1 gallon every time you fillup, will bring you up to 93 octane and be in the e15 range that a regular 93 tune can handle. So it's literally another mid-level option instead of just using 91 tunes, or all the involvement with an e30 tune. If after putting 1 gallon in, use a 93 tune and just watch your OAR and ignition corrections. If you set up a 91 and 93 map on separate slots you change on the fly or even stop and reflash off your AP if they separate files, but still easier than doing full e30

Are you on an E30 tune?

Sent from my SM-G950U using Tapatalk