[Reckless335]

So, I just found out I have a gas station really close to me that has e85. I plan to go FBO and tune for e85, but so far I only have DCI, muffler delete and a Cobb AP running stage 1 aggressive. I've read that you can run a small percentage of e85 on a stock motor. Does anyone have any experience with this? Can anyone confirm it? And if so, what percentage can I run safely? By percentage I mean how many gallons can I safely run? Assuming I have a 16 gallon tank, and I only fill up with 93 octane. Next time I fill up, how many gallons of e85 can I put in the tank to mix with 93 and still run safely?

[Reckless335]

Also, I see the JB4 guys can switch to map 5 and run e85. Does Cobb have any certain map that I can run e85 on the stock motor? I see Cobb has an e30 map, but it requires you to be FBO...... the more I see things about JB4, the more I think I should have went with that..... auto tune (map 5), 2-step, no lift shifting, change maps on the fly...... Cobb doesn't have ANY of that.

Is there a Cobb map that I can run e85? Can I run it on my current map (stage 1 aggressive)?

[stanlalee]

Newport News huh. I guess you found the Exxon (use to be BP) across from Patrick Henry. Owner says lots of BMW guys come there for E85. I would start with the Cobb e30 tune and use Accesstuner to detune or stage 1+ and up tune it along with changing the fuel scalar for E (whatever content you chose). Not going to get the E85 effect running 93 octane tunes. Been there done that. I use BT tool and Vishnu maps and even up tuning stage 1 (similar to Cobb Stage 1+) was far off enough I was better off starting with the FBO e40 tune and de-tuning it. All I have is drop in filter and 5" intercooler. Here's a log http://datazap.me/u/stanlalee/august-17th-e35-log-two

The main things I've found not aggressive enough on 93 octane tunes to take advantage of e85 were low/midrange timing and AFR. Its not going to hurt running E30 on a 93 tune, I tried it for a while but don't expect to get wowed. MAP 5 on JB4 increases boost and timing accordingly (though its not the same as running an ethanol flash tune or back end flash). NO flash tune has those "features" you mentioned BUT piggy backs without backend flash tuning is limited in fuel and timing control (flash tune is capable of much better low end tq due to piggyback limitations). There are gives and takes, you can always do both if you have to have it all.

[boost junkie]

Sell the cobb and buy a JB4 and the BT cable. Then you can switch between pump and E85 blend on the fly. This thread has a good E85 FAQ.

[Reckless335]

Originally Posted by stanlalee

Newport News huh. I guess you found the Exxon (use to be BP) across from Patrick Henry. Owner says lots of BMW guys come there for E85. I would start with the Cobb e30 tune and use Accesstuner to detune or stage 1+ and up tune it along with changing the fuel scalar for E (whatever content you chose). Not going to get the E85 effect running 93 octane tunes. Been there done that. I use BT tool and Vishnu maps and even up tuning stage 1 (similar to Cobb Stage 1+) was far off enough I was better off starting with the FBO e40 tune and de-tuning it. All I have is drop in filter and 5" intercooler. Here's a log http://datazap.me/u/stanlalee/august-17th-e35-log-two

The main things I've found not aggressive enough on 93 octane tunes to take advantage of e85 were low/midrange timing and AFR. Its not going to hurt running E30 on a 93 tune, I tried it for a while but don't expect to get wowed. MAP 5 on JB4 increases boost and timing accordingly (though its not the same as running an ethanol flash tune or back end flash). NO flash tune has those "features" you mentioned BUT piggy backs without backend flash tuning is limited in fuel and timing control (flash tune is capable of much better low end tq due to piggyback limitations). There are gives and takes, you can always do both if you have to have it all.

Holy crap, you're in Newport News too? I've never met anyone on here that was in my area. Sorry to sound like an idiot, but I'm new to tuning and I don't know how to do it myself. To be honest I'm not really even sure how to log. I'd love to learn how to tune though. If you are freesometimeI'd love to get up with you and learn a few things.

And yes, you called it, I found the Exxon that used to be BP across from the Patrick Henry Mall. I haven't met any other BMW guys in the area.

[mike@x-ph.com]

You should not run more than e35-e40 with your stock fuel pump
If you get an inline fuel pump, you can run up to e70
to run 100% without power loss ,you need to also add Vargas HPFP solution

As for Cobb, yes you need to be FBO to run e30 map

[stanlalee]

Originally Posted by latino1ny

Holy crap, you're in Newport News too? I've never met anyone on here that was in my area. Sorry to sound like an idiot, but I'm new to tuning and I don't know how to do it myself. To be honest I'm not really even sure how to log. I'd love to learn how to tune though. If you are freesometimeI'd love to get up with you and learn a few things.

And yes, you called it, I found the Exxon that used to be BP across from the Patrick Henry Mall. I haven't met any other BMW guys in the area.

If you want to do some comparisons/runs etc I'm willing but Sundays are the only days I'm free (work all day, then son's football practice from 5-8pm and part time job friday and saturday nights). I'm curious about the Cobb maps myself

[Deebo]

Originally Posted by boost junkie

Sell the cobb and buy a JB4 and the BT cable. Then you can switch between pump and E85 blend on the fly. This thread has a good E85 FAQ.

In my experience, this is not the way to go. The JB4 is great, but if you're getting into backend flashes and using the BT cable, you're better off holding onto the Cobb for flashing purposes alone. The parameters that you want to change for running high ethanol content are done with the backend flash, which takes 15 mins and your laptop with the BT cable vs about 60 seconds with the Cobb. That being said, I am talking about using E60, my JB4 without the backend flash ran great on E30. If you use the BT cable to do the backend flash, you had better make sure you have that fuel available everywhere. I switched to Cobb since I don't always have access to E85 and got a custom flash for E50 blend and can switch easily between 91 and E60. Great setup, very clean compared to the BB flash

[Deebo]

OP- try the Cobb e30 map, you will be very pleased. Octane is the key to making power on our cars

[stanlalee]

Originally Posted by Deebo

The parameters that you want to change for running high ethanol content are done with the backend flash, which takes 15 mins and your laptop with the BT cable vs about 60 seconds with the Cobb.

I think your confusing flash times with the OFT. BT tool takes under 2 minutes (mine usually take 1min 35sec). I would recommend keeping what you have. If you have the Cobb already the cheapest most effective solution is a $250 ethanol Protune and run the OTS maps for 93 octane. If you want a piggyback add it to the Cobb. I'm perfectly happy with the BT tool and tinkering with OFT OTS maps (Can't beat the price and the BT tool is useful without being able to flash).