E85 for beginners

[asiflicious]

Hey everyone, I finally found a place about 20 minutes away that has E85 gas and I'm thinking about giving it a try. 135i with catless downpipes, dci, xHP stage 3, and MHD stage 2 91 octane map. From what I understand, MHD doesn't have flex fuel so I'll have to choose an ethanol map and be precise in how much e85 to normal gas I use. I'm not sure how to go about that though. Any tips? Which map should I run and how should I go about putting in the e85? I have about a half tank of 92 in my car right now. Sorry if this is a dumb question but this is new to me

[iminhell1]

Can use a java based calc I made long time ago. I think it still works

https://www.4shared.com/file/6cBLFz7r/FuelBlending.html


Start with the v7 map.
If the car likes it you can move back to the v5 map, which is the most aggressive.

You're fuel pump won't like much over 50%. Keep a close eye on HPFP pressure. Anything near the 1000psi range you may want to reduce the E content (add more gas).

If you have a few gas cans that may be the best route for you right now.

[asiflicious]

Originally Posted by iminhell1

Can use a java based calc I made long time ago. I think it still works

https://www.4shared.com/file/6cBLFz7r/FuelBlending.html


Start with the v7 map.
If the car likes it you can move back to the v5 map, which is the most aggressive.

You're fuel pump won't like much over 50%. Keep a close eye on HPFP pressure. Anything near the 1000psi range you may want to reduce the E content (add more gas).

If you have a few gas cans that may be the best route for you right now.

Originally Posted by iminhell1

Can use a java based calc I made long time ago. I think it still works

https://www.4shared.com/file/6cBLFz7r/FuelBlending.html


Start with the v7 map.
If the car likes it you can move back to the v5 map, which is the most aggressive.

You're fuel pump won't like much over 50%. Keep a close eye on HPFP pressure. Anything near the 1000psi range you may want to reduce the E content (add more gas).

If you have a few gas cans that may be the best route for you right now.

So do I just add 3 gallons on top of my normal gas?

[BimmerAg]

Originally Posted by asiflicious

So do I just add 3 gallons on top of my normal gas?

pretty much...9 gal of gas and 3 gal of E85 will give you a mix close to E30. Flash the E30 map and you're good to go

[asiflicious]

Originally Posted by BimmerAg

pretty much...9 gal of gas and 3 gal of E85 will give you a mix close to E30. Flash the E30 map and you're good to go

Originally Posted by BimmerAg

pretty much...9 gal of gas and 3 gal of E85 will give you a mix close to E30. Flash the E30 map and you're good to go

we have 15gal tanks, including the reserve correct?
I have a full tank right now, should I just until I've used a quarter to half the tank and then add in 3 gal e85 and flash the e25 map? How much room for error is there? How precise do my calculations have to be?

[iminhell1]

STFT's can compensate +/- 25% (actually more but don't push it).

So try to error on the high side of ethanol; because of the added spark.


If you run it down to 3/4 tank, just fill the rest with E and flash the E30 map. It'll be fine.

[xQx]

Do a couple of WOT pulls and log. Look for your Low Pressure Fuel Pump pressure, High Pressure Fuel Pump pressure, AFR and timing corrections to see if the map matches your fuel and car.

Note that in many parts of the USA E85 isn't always E85 in the winter months. As an Aussie I'm not familiar with local conditions, but in colder states they sell E50 as E85 so pure E85 cars start in the snow.

If you're really getting into it I'd recommend either a flex fuel sensor or a second hand JB4.

Also, when getting advice, always confirm if someone is talking about the E85 content, or the true E content. 60% E85/40%gas mix = ~E50.

With a stock LPFP most cars can run about E30 - E40 without issue. With an upgraded LPFP most can run E60.

I pick up about 50whp extra with E60 vs pure gas. I wouldn't recommend getting a custom map until you've run on the MHD/JB4 OTS maps for at least 3 months - many people (including me) tend to go back to running pure gas in a Daily Driver because of the PITA factor.

[Bimmer TV]

Originally Posted by xQx

Do a couple of WOT pulls and log. Look for your Low Pressure Fuel Pump pressure, High Pressure Fuel Pump pressure, AFR and timing corrections to see if the map matches your fuel and car.

Note that in many parts of the USA E85 isn't always E85 in the winter months. As an Aussie I'm not familiar with local conditions, but in colder states they sell E50 as E85 so pure E85 cars start in the snow.

If you're really getting into it I'd recommend either a flex fuel sensor or a second hand JB4.

Also, when getting advice, always confirm if someone is talking about the E85 content, or the true E content. 60% E85/40%gas mix = ~E50.

With a stock LPFP most cars can run about E30 - E40 without issue. With an upgraded LPFP most can run E60.

I pick up about 50whp extra with E60 vs pure gas. I wouldn't recommend getting a custom map until you've run on the MHD/JB4 OTS maps for at least 3 months - many people (including me) tend to go back to running pure gas in a Daily Driver because of the PITA factor.

Good information!

[FtheBar.N55]

Hey wanted to chime in and see if i could get some clarity. just got my 12' N55 e82 and going to be going the MHD route this upcoming week. I live in CA so i got shitty gas and cant throw EVERY mod on her right away. She is bone stock and wanted to know is it safe/possible or even worth it once i do flash to just go with the e30 map is the one i think it would be. stock until i put my first round of mods on her? Any help MUCH appreciate