E85 and 87 Octane?

[rudypoochris]

Isn't the "15%" portion of E85 actually 87 octane gasoline? If so, just increase the amount of E85 you put in the tank during the winter months.

Ya it is. My only worry is trim out since I am not flashed.

[Flinchy]

Isn't the "15%" portion of E85 actually 87 octane gasoline? If so, just increase the amount of E85 you put in the tank during the winter months.

not sure about over your side of the world, but here, no way, 98 RON + ethanol

you can even get a 100 RON 98+E10 blend, which is really REALLY nice

[spool twice]

Have you ever tried E85 from another gas station? I always end up with weird fuel trims and timing drops when i fill @ Bollingers w/ a 3 degree average ignition correction vs. the gas station I use in Ft. Myers.

**edit** Oops, this message should be @ Jstang

[JStang]

Have you ever tried E85 from another gas station? I always end up with weird fuel trims and timing drops when i fill @ Bollingers w/ a 3 degree average ignition correction vs. the gas station I use in Ft. Myers.

**edit** Oops, this message should be @ Jstang

Unfortunately, this is the only option that I have nearby.

[lulz_m3]

http://www.zeitronix.com/Products/ECA/ECA.shtml

Put this in the glovebox, fill-up, drive for 10 mins, check your ethanol %. It uses the same anaylizer as the one Shiv is using, you might even be able to get the install kit from Vishnu, if you felt like giving them your money.

[JStang]

Was just browsing on VP Racing's site and found they have a fuel called C85 which sounds like they use the same consistent formula. Stuff is expensive though at around $10.00 / gal.

NEW! C85™
If you’re committed to using E85 type fuels, C85 is by far your best choice. Conventional E85 fuels are notoriously inconsistent, requiring up to a two-jet swing in tuning from one batch of E85 to the next. By contrast, C85 is blended with a consistent proportion of ethanol and every other component in every drum. In addition to taking all the guesswork out of tuning, C85 makes up to 4% more power and torque than conventional E85. With higher quality pure components, C85 is superior to E85 in terms of cooling effect, resistance to detonation and even includes corrosion inhibitors to fight the issues presented by ethanol. C85 works well in drag racing, oval track, off road and virtually any other automotive application, in particular forced induction applications due to its lower vapor pressure. Tests of C85 indicate most applications will require richening up by 1 jet size, or 2-3% over current jetting. Note that for racers unwilling to invest in the new carb and expensive fuel system upgrade required for E85, VP’s MS109, VP113 and Q16 continue to be the best race gas alternatives for the money.

[Sticky]

Stuff is expensive though at around $10.00 / gal.

Ya, not worth it at that price point.

[rudypoochris]

With auto tuning knowing the specific batch ethanol percentage isn't really all that valuable tbh. That being said, my station is pretty consistent.

[benzy89]

With auto tuning knowing the specific batch ethanol percentage isn't really all that valuable tbh. That being said, my station is pretty consistent.

AutoTune can't know the specific ethanol content, not unless an ethanol sensor has been installed. This is why I'm strongly considering the switch to a ProEFI unit (and ethanol sensor) when it's released for the N54. Basically it's tuned for 93 octane & then straight E85/E100 (or as close without maxing fuel trims). Anything that's blended in between (E40, E60, etc), the tune is automatically adjusted (specifically the timing & fueling) to maximize performance.

[rudypoochris]

AutoTune can't know the specific ethanol content, not unless an ethanol sensor has been installed. This is why I'm strongly considering the switch to a ProEFI unit (and ethanol sensor) when it's released for the N54. Basically it's tuned for 93 octane & then straight E85/E100 (or as close without maxing fuel trims). Anything that's blended in between (E40, E60, etc), the tune is automatically adjusted (specifically the timing & fueling) to maximize performance.

Like I just said, knowing the specific ethanol content really isn't that important. What you care about is knock resistance and required fueling increase which can be determined from timing and trims. In an ideal world, we would have an ethanol sensor to allow for the best possible tune and consistency without auto tuning algorithms. The reality is the difference in power is miniscule and not really worth the effort imho. If you can come up with a legitimate safety or power gain from a sensor based setup at this time, I'd be surprised.

[Terry@BMS]

AutoTune can't know the specific ethanol content, not unless an ethanol sensor has been installed. This is why I'm strongly considering the switch to a ProEFI unit (and ethanol sensor) when it's released for the N54. Basically it's tuned for 93 octane & then straight E85/E100 (or as close without maxing fuel trims). Anything that's blended in between (E40, E60, etc), the tune is automatically adjusted (specifically the timing & fueling) to maximize performance.

But given the ethanol content you still won't know much boost and timing your car will safely take for any given conditions. It's fine to have an ethanol sensor as another piece of the puzzle, but without auto tuning it's all for nothing IMHO.

[spool twice]

Unfortunately, this is the only option that I have nearby.

FWIW on my last fill @ Bollingers with 10 gallons E85/the rest with his ethanol free 93 octane, I couldn't get clean timing even with map 1 (13psi target).

I talked to the guy on my last fill and was told that his E85 isn't that popular, they go there more for the ethanol free gas. That sort of tells me that the ethanol is aged... which explains the lackluster performance, even at 13psi, elevated fuel trims, and plausible fuel pump codes I get when I fill there.

[JStang]

FWIW on my last fill @ Bollingers with 10 gallons E85/the rest with his ethanol free 93 octane, I couldn't get clean timing even with map 1 (13psi target).

I talked to the guy on my last fill and was told that his E85 isn't that popular, they go there more for the ethanol free gas. That sort of tells me that the ethanol is aged... which explains the lackluster performance, even at 13psi, elevated fuel trims, and plausible fuel pump codes I get when I fill there.

I have been getting protuned by PTF and my logs are showing a lot of timing corrections. Enough that Jake thinks my plugs might need replaced (and they probably do). Have you tested the content?

[spool twice]

I have been getting protuned by PTF and my logs are showing a lot of timing corrections. Enough that Jake thinks my plugs might need replaced (and they probably do). Have you tested the content?

I've not been back since so I don't have a sample. I would love to test it, I'm willing to bet it's no more than a 10% mix.

I too replaced my plugs (13K on my last one) thinking that was the reason. I even sent logs to Terry but we both couldn't figure it out. As soon as the tank ran dry, I poured in E85 that I stored away in 5 gallon tanks from Marathon in Ft. Myers and mixed with 4 gallons 93 and my car returned back to normal.

Gohr (E90post member) is having issue's with Bollingers E85 as well. No matter how much "E85" he's added, he has 3-4 timing corrections (avg correction value of 3.5).

If you head out to Orlando again to get tuned, stop at the E85 station in Orlando, I've had good luck with that gas station. It would more than likely resolve the timing corrections. Have you tried just running E85/93 with the standard COBB Stage 2+ timing curve to see what corrections you have vs. just running straight 93?

[rudypoochris]

Update:

Added 14 gallons to it at a 55% E85/87 mix. Did a couple pulls, no run lean, no misfire, etc. Pulled codes, have a mixture control, but I always have those at over 50% mix. So first part of the test looks good in that 87 doesn't have anymore ethanol in it than 91.

The autotune shows 1.6 avg ign and autolearn 14 (normally 0 avg ign and 15 autolearn). This is worse than normal, but may be due to the fact that I cant get a solid 3rd gear pull down to complete the learning (clutch is slipping and there is too much traffic). I will log later when I get some free time to see what the timing looks like. That will be the real metric of "worth it or not". Who knows, maybe 87 has less ethanol than 91 and 91 is just 87 with ethanol in it to boost the octane.

Not sure what the performance difference is yet (if any) and not sure if the price difference is enough to make it worth choosing one or another. I always rather spend less than more though. Also if you are flashed I'd imagine using 87 could cut your raised timing curve sooner than it would mine.

[rudypoochris]

Finished the tank. No butt dyno difference in performance, still hit 17.5psi and timing was perfect with avg ign between 0 and 0.7. I am going back to 91 though since I like having full power even if I miscalculate and get only 40% instead of 50%. Plus, cheap insurance. I assume with higher boost or more than piggyback max timing you would see the octane limit sooner. I didn't experience it personally though.

[vasillalov]

I don't get it?

You will always be covered with an E60 tune pouring E85 100% in. You aren't leaving much on the table if anything with stock turbos in this scenario since you are already boost capping and will have enough octane to run the most aggressive of timing.

...but it is NOT only about knock. It's also about fuel volume. You run 100% E85 and you tune for E60, then you'll be most probably running very lean.

[rudypoochris]

...but it is NOT only about knock. It's also about fuel volume. You run 100% E85 and you tune for E60, then you'll be most probably running very lean.

Its piggyback with no flash, running 50-55%. I am right under the trim ceiling. Jb4 G5 is setup to run leaner than most with E85. I am totally okay with that, been running this way for over 35k miles. This test was really just a test of can I substitute 87 for 91 and get the same results at this boost level (17.5psi).