• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

e85

hollas13

New member
Can you run an e85 mix with out needing to be tuned for it? Regular pump 93 is about 10% ethanol already so if you increase it to say about 20% can this be done Safely.
 


As in you have to plan routes around e85 stations. Ive seen guys miss car meets dues lack of e85 availability. No sugerwater for me thanks
 


There are octane calculators for mixing e85 with premium. Google it. Just be careful with out a tune. Trims can only do so much. And I would rather miss a meet and have e85 then go with out. The stuff is the best thing to happen to man kind and now POET (A leading manufacturer) can make the stuff out of anything that was once green and alive.
 
There are octane calculators for mixing e85 with premium. Google it. Just be careful with out a tune. Trims can only do so much. And I would rather miss a meet and have e85 then go with out. The stuff is the best thing to happen to man kind and now POET (A leading manufacturer) can make the stuff out of anything that was once green and alive.

On that note, what would be recommended for me to change in my current tune to safely allows an E85 mix? Should I change target AFRs?
 


You need to tune your MAF curve and fueling like you would for most anything. I adjusted my injector size by 30% to make it seem like they were smaller so they flowed more and then adjusted my maf curve and target afrs from there. Once your get your curve near perfect you can just set your targets. ALWAYS SCAN FOR KNOCK AND AFR.
 
You need to tune your MAF curve and fueling like you would for most anything. I adjusted my injector size by 30% to make it seem like they were smaller so they flowed more and then adjusted my maf curve and target afrs from there. Once your get your curve near perfect you can just set your targets. ALWAYS SCAN FOR KNOCK AND AFR.

Makes sense... not to thread jack, or change the intent of this thread, but why are the MAF curves necessary to change? I have done a ton of tuning on my current setup, but have never changed the MAF curve. AFRs on the wideband show up just fine and the car is showing extremely close to the target AFRs the ECU is commanding (which I set).

Also, how do you adjust the injector size? what table is that in in the tune?
 
When you get deeper into modding you'll have to start tuning your curve. Frankly I went from a 3.8 straight to a 3.2 and just tuned the maf. Me and frosty usually do either a wideband tune or a maf tune if no wideband is available.

We have our wideband output wired into the EGR pintel position and we log that against the target and then adjust from there.
 
When you get deeper into modding you'll have to start tuning your curve. Frankly I went from a 3.8 straight to a 3.2 and just tuned the maf. Me and frosty usually do either a wideband tune or a maf tune if no wideband is available.

We have our wideband output wired into the EGR pintel position and we log that against the target and then adjust from there.

I see.. I guess one could change the commanded AFR, and/or the MAF curve and achieve the same result?? increase the MAF curve to "trick" the ECU into believing it is seeing more air than it really is to get some additional fuel?

How would you recommend changing the MAF calibration for an E85 setup or E85/regular mix? Just scale the entire curve up?
 


I will have to take a look at that HP Tuners thread to check out MAF tuning. No intent on rigging anything. Guess I just need to better understand what scaling back injectors really involves and how it works.

I have hoped/planned on switching over to E85 at some point all along. Been looking for a good set of used 42.5 or 60 lb injectors for the changeover. Hence why I really need to learn how to scale and tune for injector changes.
 
Last edited:
Back
Top