How to run E85 on stock 86 BRZ FRS with OFT tune

[steve99]

Originally Posted by Texas2016Frs

Do you think that once the ecu learns the trims again it will run less rich?

It learns pretty quick, you can speed up the learning with several light throttle runs in 2nd or 3rd from 2000-5000 or so.

if its still running on the rich side after that then you going to need to adjust the Open loop maf scaling ie the values over about 3.2 volts, if your running 5% rich decrease the values above 3.2 volts 5%.

Or have a read of the maf scaling thread links below and just use the VGI utility to do the open loop section of maf scaling, best leave the closed loop alone.

[ANTLAY]

Hmmmm... There are finally a few,very few local stations with e85,and I'm considering trying it out,is everything in the OP still accurate?

[steve99]

Originally Posted by ANTLAY

Hmmmm... There are finally a few,very vew local stations with e85,and I'm considering trying it out,is everything in the OP still accurate?

To the best of my knollegde yes been on e85 for two years

[ANTLAY]

Originally Posted by steve99

To the best of my knollegde yes been on e85 for two years

Thanks man, may be making the switch soon,just need one store a little less outta the way to pick it up,right now I'd have to travel around 10 miles of course of my commute to fill up,so a bit on the fence for now.

[steve99]

Originally Posted by ANTLAY

Thanks man, may be making the switch soon,just need one store a little less outta the way to pick it up,right now I'd have to travel around 10 miles of course of my commute to fill up,so a bit on the fence for now.

I bought a couple of 20 litre plastic gerry cans to fill as well as tank

[eurominican]

Originally Posted by steve99

To the best of my knollegde yes been on e85 for two years

@steve99 thanks for all you do for us here in the forum!

This may be a dumb question and its kind of answered in the op but just for my peace of mind:

Why would a flexfuel kit be better (necessary?) than running just the oft with e85 tune? This, of course, not taking into account custom tunes which will always be better than canned tune since its custom to the specific vehicle.

I'm a member of a local Facebook page for FRS/BRZ and everyone was bashing running e85 without flexfuel kit.

Tia!

Sent from my SHIELD Tablet using Tapatalk

[kch]

Originally Posted by eurominican

Why would a flexfuel kit be better (necessary?) than running just the oft with e85 tune?

Ignoring the custom tune issue, it's mostly for convenience. If you don't have a ready supply of E85, or if you do a lot of road trips, it's a pain in the ass to drain the tank and switch fuels. With a full flex fuel setup, you just put in whatever fuel you have around.

[steve99]

Originally Posted by eurominican

@steve99 thanks for all you do for us here in the forum!

This may be a dumb question and its kind of answered in the op but just for my peace of mind:

Why would a flexfuel kit be better (necessary?) than running just the oft with e85 tune? This, of course, not taking into account custom tunes which will always be better than canned tune since its custom to the specific vehicle.

I'm a member of a local Facebook page for FRS/BRZ and everyone was bashing running e85 without flexfuel kit.

Tia!

Sent from my SHIELD Tablet using Tapatalk

Originally Posted by kch

Ignoring the custom tune issue, it's mostly for convenience. If you don't have a ready supply of E85, or if you do a lot of road trips, it's a pain in the ass to drain the tank and switch fuels. With a full flex fuel setup, you just put in whatever fuel you have around.

Elthanol content of most e85 fuel varies this variation can be between about 60 and 90℅ ethanol.

The ecu has a built in mechanism to cope with this ie fuel trims both long and short term., however these take a while to react. On a naturally aspirated car it generally ok as your not pusing the limits, on a boosted car you rearly need much faster response to ethanol content change ie a flex fuel sensor\kit. Unless your running a controlled e85 fuel that does not vary.

On an NA car flex setup is very convienent as the other guy said you can switch fuels or mix petrol ethanol any ratio you like no problem no reflashing.

but if your just sticking to e85 between about 60-90 % ethanol then your good without a flex kit jist give it a few miles to relearn each time you fill up with e85 incase their was a big shift in ethanol percent.

if you have oft you can monitor ltft hopefully, its less than about 10% , you can set uptuning alerts to alert you if the ltft goes over say 12% + or - this will alert you if you accidently put petrol in car.

I did a test a while back and ran down to about e40, and tune coped ok after learning of trims some minor knock , would not track it or anthing but its amazing flexible

If you ever get stuck on a e85 tune with no device to flash back, you can put petrol in just enough to get you home or to next station and drive light throttle below 3500 rpm and you will be fine you will run big fuel trims but at light throttle low rpm petrol and e85 tunes are not that much different.

[eurominican]

Originally Posted by steve99

Elthanol content of most e85 fuel varies this variation can be between about 60 and 90℅ ethanol.

The ecu has a built in mechanism to cope with this ie fuel trims both long and short term., however these take a while to react. On a naturally aspirated car it generally ok as your not pusing the limits, on a boosted car you rearly need much faster response to ethanol content change ie a flex fuel sensor\kit. Unless your running a controlled e85 fuel that does not vary.

On an NA car flex setup is very convienent as the other guy said you can switch fuels or mix petrol ethanol any ratio you like no problem no reflashing.

but if your just sticking to e85 between about 60-90 % ethanol then your good without a flex kit jist give it a few miles to relearn each time you fill up with e85 incase their was a big shift in ethanol percent.

if you have oft you can monitor ltft hopefully, its less than about 10% , you can set uptuning alerts to alert you if the ltft goes over say 12% + or - this will alert you if you accidently put petrol in car.

I did a test a while back and ran down to about e40, and tune coped ok after learning of trims some minor knock , would not track it or anthing but its amazing flexible

If you ever get stuck on a e85 tune with no device to flash back, you can put petrol in just enough to get you home or to next station and drive light throttle below 3500 rpm and you will be fine you will run big fuel trims but at light throttle low rpm petrol and e85 tunes are not that much different.

Just like I expected, very good summary/explanation!! This should be in the op! This is exactly what I understood but everyone seemed so apprehensive of running e85 without flexfuel sensor.

I feel much more confident / at ease now with this setup. I always refill as same station near my house and let the ecu relearn after. Big thumbs up to @steve99 and @shiv !!

Sent from my Nexus 6 using Tapatalk

[steve99]

Originally Posted by eurominican

Just like I expected, very good summary/explanation!! This should be in the op! This is exactly what I understood but everyone seemed so apprehensive of running e85 without flexfuel sensor.

I feel much more confident / at ease now with this setup. I always refill as same station near my house and let the ecu relearn after. Big thumbs up to @steve99 and @shiv !!

Sent from my Nexus 6 using Tapatalk

you might be interested in setting oft alerts as per here
http://www.ft86club.com/forums/showp...&postcount=430

[LOLS2K]

Do we still have to adjust the Fuel Multiplier Display Offset when running e85 map? Or is this already built in on the newer OFTs?

[steve99]

Originally Posted by LOLS2K

Do we still have to adjust the Fuel Multiplier Display Offset when running e85 map? Or is this already built in on the newer OFTs?

Yes you will still need to adjust fuel multiplier to get the dash display to read correctly. It does not effect performance

[thambu19]

@steve99: Any idea why Openflash recommends running the EL E85 tune over the UEL E85 tune for those running stock setup with E85? I thought our stock headers were Unequal length. Shouldn't we be rocking the UEL E85 tune then?

[steve99]

Originally Posted by thambu19

@steve99: Any idea why Openflash recommends running the EL E85 tune over the UEL E85 tune for those running stock setup with E85? I thought our stock headers were Unequal length. Shouldn't we be rocking the UEL E85 tune then?

stock header is stepped 4-2-1 its fairly equal lengtth, ie closer to equal than unequal.



good to see your back :-)