Yes, I've searched, for hours, and can't seem to get the right answer, or maybe I just don't know what I'm looking for. I plan to make the switch to e85 shortly, and I know the hardware I need. What I don't quite know for sure is what I need to do to my ROM. Obviously I will need to change my fuel and ignition maps, but I don't know what AFR I should be targeting, or how to judge the correct amount of timing, since e85 won't knock. I am tempted to copy a few of the maps I have seen here as a starting point, but I'm not sure if this is a good idea....any input would be appreciated, or if this has been covered and I just can't seem to find it, feel free to burn me a little and maybe point me in the right direction...thanks.

 

I know that alot of us are DIYers, but when it comes to a tune on a different fuel I would be inclined to say leave that to the pros. Self tuning it yourself eventually you will be able to tweak it enough to get it where you want it, but at what cost. You may break a few things or hurt your motor and I'd rather just pay to have it done right the first time.

 

My problem is there isn't a single tuner that I know of in my state....closest is MAP in the Minneapolis area, which is a 9-10 hour drive. If that's what it comes down to, I'll have to go that route, but I'd like to say that I have the skills necessary...I've been a tech for 12 years now, but have yet to deal with alternative fuel conversion.

 

I was in the same boat. I hadn't tuned before but I studied the main E-85 threads like E85 Timing Maps, E85 Hints and Tips, Maybe this one. What I did was switched to V7 scaled my injectors on pump first, then let the tank run almost out of pump and put in E85. Then I rescaled my injectors for E85 by multiplying my pump scaling by .7 (per directions on Injector Scaling Super Merge). Then to see if the scaling needed to be raised or lowered I set every cell above 100% load to 12.0 and ran it into boost a few times to see what my afr's were. If its leaner than you need to lower the scaling if it's richer you need to raise the scaling. I found a document on here called Merlin's EcuFlash tuning guide. I can email you the doc if you want. Anyway after I got my scaling correct I adjusted my fuel map back to how it was on pump and then I just added fuel or took fuel away where necessary, tried it out and just did trial and error from there on out. Target afr's for e85 from what i've researched is 12's spooling up and 11:8-12 at WOT. Just do your research and study the stuff all the guru's on here have found works. Goodluck

 

Thank you very much for your very informative response...don't see enough of that on here.

 

AFR's like the above post of ValdezeEvo should be in the 11.8-12.0'ish range. As for timing you are kinda screwed as for getting the best tune unless you have a dyno where you can tune for MBT.

 

The scaling will change your AFR's but the correct way to change AFR is through the fuel map only IMO and AFTER your injector scaling is set by insuring your trims are are plus or minus around 3% some shoot for lower and some say 5% is OK. I believe this is a better way of doing it everyone else's opinion and mileage may vary.

Best wishes and good luck

PS Over 20k miles of pure e85 and no issues to date

 

That's what I was afraid of...sounds like if I'm going to have to have the ignition tuned on a dyno, I may as well have the whole thing done on a dyno....Looks like I'm going to have to make an appt. with MAP in the future...after I get the hardware anyway. Thanks for all the info!

 

You could use Jack of Trades Virtual Dyno Room software dyno to measure your torque during ignition tuning.