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

[Andrew025]

Originally Posted by Kelbyat07

Yeah I already read that but I just wanted to make sure so I risk ruining my car. Didn't make sense to me that you had to flash after you put E85 in your car...

If you flash E85 tune before most of the gas is out of the lines, it'll lengthen the learning process since it has to do it twice (learning for the gas and then the ethanol once most of the gas is gone).
That's why you wait to flash the E85 tune.

[Kelbyat07]

Originally Posted by Andrew025

If you flash E85 tune before most of the gas is out of the lines, it'll lengthen the learning process since it has to do it twice (learning for the gas and then the ethanol once most of the gas is gone).
That's why you wait to flash the E85 tune.

That makes a lot of sense now. I am still new to OFT so bare with me.
Does it matter if you fill up the whole tank with E85 for the first time when flashing or is filling half way ok

[steve99]

Originally Posted by Kelbyat07

That makes a lot of sense now. I am still new to OFT so bare with me.
Does it matter if you fill up the whole tank with E85 for the first time when flashing or is filling half way ok

Yes you must completly fill tank you near empty tank with E85 or it will be too diluted with the remaining petrol in tank on switchover.

remember your running a dedicated E85 tune or a dedicated petrol tune.

reverse proceedure to go back to petrol.

[Trettiosjuan]

Just a reminder not necessarily directed at the above posters:

If E85 availability is a problem and/or you:
- Have to switch over emptying and brimming tanks and reflashing if doing long or unpredictable trips.
- Make detours every time you need to fill up, which will be quite often, to get the % you need.
- Use E85 fuel of varying quality from different pumps and drive about for hours worrying about ltft and staring at your oft display wondering if it's safe to give it some.
- Do give it some but worry if varying quality will do damage.

If one or several apply, do know that there are flexifuel kits available that read ethanol content in the fuel lines before they reach the injectors and give freedom to use any mix of E85 and gas...

Just stating the obvious, seems some people are messing around with OFT when the fitting performance upgrade would be to spend a little more on a proper flexifuel kit and then enjoy driving where you want...
Detours every time you need to fuel up or reflash also costs time and money and I'm betting that the station isn't at the end of a twisty mountain road that you don't mind driving...

[s2d4]

Meh, just a change of habit.
Good reason to take the car out for a spin anyways.

[Trettiosjuan]

If it works for you it's all good! It's just easy to fall into the short term thinking trap, been there done that and such... Very pleased with my OFT here too

[s2d4]

Originally Posted by Trettiosjuan

If it works for you it's all good! It's just easy to fall into the short term thinking trap, been there done that and such... Very pleased with my OFT here too

Yeah, knowing what you are doing isn't a bad thing evidently.
I plan my trip to get the fuel I want even on my other cars, people should never put in whatever come up at the first gas station for cars such as ours.

[Wayno]

I'm now running these values (based on stock tables)

<= 10C/50F values multiplied x 1.5
20C/68F values multiplied x 1.4
30C/86F values multiplied x 1.3
40C/104F values multiplied x 1.2
50C/122F values multiplied x 1.1
60C/140F values multiplied x 1.05

And Shiv's Cranking IPW Comp A in addition to that.

[tracerit]

Originally Posted by steve99

I would think that shiv did that tune on the average percent of ethanol found in E85 in his area , probably around the middle of that range ie about E70 , this should correspond to where the average LTFT is the least.

You have enough octane rating even at E60 its just the fuel trims will be high.

As we have a guaranteed E85 pump fuel here i just rescaled maf to suit and hence fuel trims around 3%.

I've been testing my E85 and has come out to 85% +/- 2% both times so far. I end up mixing with US 91 gas to the E70 mix you suggested and have gotten LTFT 0-6% which is better than the 10-15% I get going with straight E85 in the past before I tested.

If I want to stick with E85 @ 85%, do I just need to rescale the MAF or do I need to adjust timing and knock as well? Mixing the fuel is pretty tedious so if I can adjust the ECU to handle E85 @ 85% and just straight fill up that would be easier.

[steve99]

Originally Posted by tracerit

I've been testing my E85 and has come out to 85% +/- 2% both times so far. I end up mixing with US 91 gas to the E70 mix you suggested and have gotten LTFT 0-6% which is better than the 10-15% I get going with straight E85 in the past before I tested.

If I want to stick with E85 @ 85%, do I just need to rescale the MAF or do I need to adjust timing and knock as well? Mixing the fuel is pretty tedious so if I can adjust the ECU to handle E85 @ 85% and just straight fill up that would be easier.

Yes if you have consisentent e85 that is 85% ethanol then as you found you will get bit trims as ecu compensates. yes you could scale maf to suit as i have done correct after maf scaling check you fueling and for knock.

[FRS Johnny]

So I've ran e85 before. I recently only drive the car on the weekends. I searched around and couldn't find the answer I was looking for. I know someone talked about it before. How long can you keep e85 in your tank? are there any negatives if you keep it in the tank for over a week?

[Wayno]

Originally Posted by FRS Johnny

So I've ran e85 before. I recently only drive the car on the weekends. I searched around and couldn't find the answer I was looking for. I know someone talked about it before. How long can you keep e85 in your tank? are there any negatives if you keep it in the tank for over a week?

Over a week is fine, it's when you start counting multiple months.

[FRS Johnny]

Originally Posted by Wayno

I'm now running these values (based on stock tables)

<= 10C/50F values multiplied x 1.5
20C/68F values multiplied x 1.4
30C/86F values multiplied x 1.3
40C/104F values multiplied x 1.2
50C/122F values multiplied x 1.1
60C/140F values multiplied x 1.05

And Shiv's Cranking IPW Comp A in addition to that.

Hows this working out for you? It doesn't really get that cold in CA. But I've had issues cold starting. So I might do the cold start thing if I have issues again.

[Wayno]

Great except change 50 and 68 columns to be 200% of stock now, closer to mkivsupra's values.