[Fun w/N54]

Will a stock or modified car but wo/tune benefit with 20-30% mixture of E85?

[MikeB@fftec]

Short answer, don't do it. Your car would need to be tuned in order to use the E85.

[jdbretz]

Originally Posted by Fun w/N54

Will a stock or modified car but wo/tune benefit with 20-30% mixture of E85?

No, not at all. The benefit comes from a tune being able to increase boost and/or run a more aggressive ignition advance due to the higher octane afforded by the E85. The stock mapping will not take advantage of the higher octane, so there will be no benefit.

[JamesM3M5]

That and you'll have weird fuel trims since it takes a greater quantity of E85 to make the same power as gasoline. The stock programming won't have the proper fuel injection mapping to deal with the higher fuel volume demands that E85 places on the fuel system. It can compensate within +/-34%, but still, do not run high E85 content without proper tuning.

[Fun w/N54]

So to take one step further, for the people running E85 mixture with Cobb (as an example) they have a special tune other than the available beta 4.01 or will the sport/aggressive maps sort this out?

Thanks again.

[AU335i]

Originally Posted by Fun w/N54

So to take one step further, for the people running E85 mixture with Cobb (as an example) they have a special tune other than the available beta 4.01 or will the sport/aggressive maps sort this out?

Thanks again.

alot of guys with COBB are going to use ATR to run a special e85 blend... theres a thread about it on currently floating around!

[benzy89]

Originally Posted by Fun w/N54

So to take one step further, for the people running E85 mixture with Cobb (as an example) they have a special tune other than the available beta 4.01 or will the sport/aggressive maps sort this out?

Thanks again.

If you're just using OTS maps, a 20% blend (3 gallons of E85 per 1 full tank of 91/93) is a safe & beneficial blend. Don't expect to see monsterous gains like the guys mixing 50:50 with the plug-in tunes tho. You'll get a marginal bump in performance, but more importantly it'll kill any timing corrections.

As of right now, you need to use ATR or have a ProTune Map made if you're gonna use E85 with the COBB tune

[wickedgtr]

I noticed improvements by running a few gallons of e85 when completely stock -- but we only have 91 octane here and its over 110 daily. It's nothing like it is when running the e85 maps/tunes. At least for me, it seemed to allow the car to run how it was intended, and very consistent.