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

[LOLS2K]

Thanks for the reply. I still like the OFT option and may choose to go about it in stages. Install OFT with e85 tune>buy ECA2>build fuel lines>and read e% off the Zeitronix gauge. Just to clarify, the ECA2 will work independent of a complete flex fuel kit with plumbing and plug n play harnesses, correct? Meaning I can run an ECA2 and wire it all up per Zeitronix instructions and still read e% .

[tracerit]

I'm looking to adjust the cranking values but according to RomRiader I have more tables than what I've seen in the forum. I have Cranking Fuel IPW A to J, whereas all the pictures I"ve seen are from A to E only. Do I change all the tables on my end or just tables A to E?

[steve99]

Originally Posted by tracerit

I'm looking to adjust the cranking values but according to RomRiader I have more tables than what I've seen in the forum. I have Cranking Fuel IPW A to J, whereas all the pictures I"ve seen are from A to E only. Do I change all the tables on my end or just tables A to E?

Just changing A to E will get you going, your defs must have more tables defined sounds like your using kodename47 defs
just make sure no weird values in the tables.

you could up the vales in the remaining tables by the same percentage increases over stock if your kean.

[JDsThatGuy]

How often are you guys changing your oil and which type of oil are you running with E85? I've heard instead of 3-5k miles we should be changing the oil closer to 2k when running E85

[steve99]

Originally Posted by JDsThatGuy

How often are you guys changing your oil and which type of oil are you running with E85? I've heard instead of 3-5k miles we should be changing the oil closer to 2k when running E85

use an oil thats SN or GF5 rated or one thats specifly states its E85 compateble. You can half the change interval if you want but if your NA and your not running rich and getting fuel dilution you can likely go the normal intervals with an e85 compatable oil

[thambu19]

An alternative to messing with the tables for cold start is to crank once for a short interval then turn off and wait 3-4 seconds and crank again. The fuel injected at the port in the first cranking will evaporate enough to start the car at the second crank.

[steve99]

Originally Posted by thambu19

An alternative to messing with the tables for cold start is to crank once for a short interval then turn off and wait 3-4 seconds and crank again. The fuel injected at the port in the first cranking will evaporate enough to start the car at the second crank.

This will work for guys on say E70 or so but guys on higher E content like E85-E90 its either just wont start or you will be cranking 6 times or more especially when its below 50F.

High E content guys can add a bit of petrol though, but editing the tables is a better option .

[Kronos]

And on a side note, if I remember correctly, we are maxing out power at like E50-60 or something so no biggie not getting exactly E85. Anything extra is just gravy


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[perry753]

Hi Steve,

First time posting and thank you for your information.

What is the difference between the OFT branch and Alpha branch on Github when flashing OFT or modified OFT tunes? I am using the E85 Stage 2 maps but will be editing my map to copy over the new cranking values from Wayno's thread. I don't remember where I got the definition file when I was tuning last time.

Alpha branch definition for B00C: https://github.com/TD-D/SubaruDefs/b...Z/ZA1JB00C.xml
OFT branch definition for B00C: https://github.com/TD-D/SubaruDefs/b...C/ZA1JB00C.xml

Everything in these two files is the same except for the addition of two tables in the OFT branch's file. Their names are 1. Engine Load Limit B Maximum (RPM) and 2. Engine Load Limit C (Maximum) (RPM). I suspect that I should be using the definition from the OFT branch given that there is a patch for LC/FFS, but I do recall using the definition from the Alpha branch when I flashed and still having the LC/FFS feature when driving.

Diff: https://gist.github.com/perryh/cc710783b829eb698fb4

Thank you!

[steve99]

Originally Posted by perry753

Hi Steve,

First time posting and thank you for your information.

What is the difference between the OFT branch and Alpha branch on Github when flashing OFT or modified OFT tunes? I am using the E85 Stage 2 maps but will be editing my map to copy over the new cranking values from Wayno's thread. I don't remember where I got the definition file when I was tuning last time.

Alpha branch definition for B00C: https://github.com/TD-D/SubaruDefs/b...Z/ZA1JB00C.xml
OFT branch definition for B00C: https://github.com/TD-D/SubaruDefs/b...C/ZA1JB00C.xml

Everything in these two files is the same except for the addition of two tables in the OFT branch's file. Their names are 1. Engine Load Limit B Maximum (RPM) and 2. Engine Load Limit C (Maximum) (RPM). I suspect that I should be using the definition from the OFT branch given that there is a patch for LC/FFS, but I do recall using the definition from the Alpha branch when I flashed and still having the LC/FFS feature when driving.

Diff: https://gist.github.com/perryh/cc710783b829eb698fb4

Thank you!

Looks like just the two load limit tables added to definition.

unless you want to edit those two specific additional tables it does not matter.

always check some tables in the rom before you flash and make sure the values and axis look ok, also if you going to edit lc\ffs make sure the rom has the patch see the romraider tips link its still valid for ecuflash.



ignore this weird icon thing cannot delete it on my phone

[thambu19]

Originally Posted by Kronos

And on a side note, if I remember correctly, we are maxing out power at like E50-60 or something so no biggie not getting exactly E85. Anything extra is just gravy


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Maxing out at normal intake temps or even at extended intake temps? From experience E85 can get us to MBT (best torque) combustion usually but as the temps rise it is possible that we can get into slight knock limit.

Although most OEMs launching flex fuel vehicles can exploit the octane boost of E85 no one does because of the risk due to max rise of pressure being higher with engine running E85 at WOT.

So when they calibrate spark they make sure that the peak pressures seen are reasonable to what is obtained on premium fuel. This is because most hardware design is done to certain specification and in most cases it is limited to the pressures and temperatures that would be normally seen using regular gas. The durability team will normally not allow the E85 calibration team to reach its full potential since the HW in most cases could fail. It appears that Toyota/Subaru might have intentionally strengthened the GT86 platform expecting mods. But only time will tell.

[thambu19]

Originally Posted by Kronos

And on a side note, if I remember correctly, we are maxing out power at like E50-60 or something so no biggie not getting exactly E85. Anything extra is just gravy


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One other piece of information is with E85 although the knock tolerance is high, if we get to knock limit it could switch to Pre-ignition straight away unlike regular gasoline.

In our cases this might not be a big deal because as you said E50-60 is good enough and E85 is a bonus

[perry753]

Love using E85 so far. Propel in the bay area offers a gallon for $2.20-2.30 currently.

[nelsonzep]

I did this correctly as you have stated but after about 20 miles on e85 tune driving under 3500 rpm i get check engine light and p0171 too lean code. also after about 40 miles the ltft is still around 35% and hasnt gone down. I currently have 02 spacers on my headers could this be causing the problem? i read that it is either 02 sensor/ maf sensor failure or leak in exhaust/intake? but could it be my spacers?