Flex Fuels

[dh58]

Is anyone running on e85 or something else for their 1er? If so, hows that going?

I saw a thread where a guy ran ron98 and the compared with e85 and shaved 1/3 of a second off his 1/4 time.

[Caduceus]

Ive been running ~E25 for the past 40,000km. All the console operators know me at the local Caltex by the unusual way I buy fuel. Essentially I run the tank to near empty, then put 32 litres of 98 in it, hang up the pump, wait 1 minute for the bowser to reset then put 16-18 litres of EFlex to top it up to full. Pay for both amounts together on the one transaction. Simple really.

Performance wise, I run JB4 on map 5 and it hasn't missed a beat. Easily makes more power than straight 98 on map 2. I have no other mods. Have run a 12.5 quarter mile at Willowbank using this fuel and tune so power is excellent.

Average fuel consumption increased very slightly from 9.7 to 10.0 l/100km but filling the tank this way is cheaper than regular 91 unleaded (not that you'd do that) and it performs better than MS109 race fuel that costs over $5 per litre. I bought a 20 litre drum to use once at the drags - wont do that again since "discovering" the benefits of Ethanol enriched fuel.

I replaced a HPFP on the car BEFORE I started with E25 but 60,000k later (40k with Eflex) the current one is running strong.

What's not to like?

[The Wind Breezes]

E85 can support a *whole* lot of power over RON 98 with proper tuning as it burns cooler and has extremely high knock resistance. So, you can run more boost / leaner equivalent mixture than with the same EGT on gas, and all with closer to ideal timing.

The mixes support proportionately less power, but you'd probably want a fuel cell to run full E85 cuz the fuel tank is really small as it is.

[BMWhoarder]

i've been running E50-E60 consistently for the last 9 months without issue with my Jb4 and a slightly modified E85 backend flash.

If you don't have a flash to adjust your scalars and afr targets, you can probably get away with around E20-E25 without maxing the trims.

Fuel economy is significantly worse, both due to your right foot enjoying the power more, and the fact that ethanol's lower energy content means you burn up to around 30% more compared to standard unleaded fuels.

[7smurfs]

I looked into this however my car was coming up with gremlins to fix whilst running RON 98 fuel.

Looks like a backend flash is recommended alongside map 5 jb4

[135]

Originally Posted by Caduceus

Ive been running ~E25 for the past 40,000km. All the console operators know me at the local Caltex by the unusual way I buy fuel. Essentially I run the tank to near empty, then put 32 litres of 98 in it, hang up the pump, wait 1 minute for the bowser to reset then put 16-18 litres of EFlex to top it up to full. Pay for both amounts together on the one transaction. Simple really.

Caltex's Bio E-Flex is a flexible ethanol content fuel and is in the range of 70-85% ethanol, depending on the season (although it probably rarely reaches 85% even in the summer), so your mix will be E25-E30, based on a 18:32 litre mix. With a flex fuel, unless you have an ethanol tester that you use to test a sample from every fill, you won't know what your mix is. To make matters worse, if you happen to partial fill, it will be even more difficult to know what your final ethanol mix is. You won't have fuel consistency and, therefore, any tuning or dyno figures won't be comparable.

United Fuel is known to be a minimum of 85% (measured up to 88%) so if you have access to United E85 (or United E85 Race) then that would be a better option for consistency.

[OzJustin]

Assuming you have the low & high pressure fuel pumps to support straight E85 have any of you Cobb users had a custom flash prepared to support this? (No Backend JB flashes)

[BMW86]

Originally Posted by Caduceus

Ive been running ~E25 for the past 40,000km. All the console operators know me at the local Caltex by the unusual way I buy fuel. Essentially I run the tank to near empty, then put 32 litres of 98 in it, hang up the pump, wait 1 minute for the bowser to reset then put 16-18 litres of EFlex to top it up to full. Pay for both amounts together on the one transaction. Simple really.

Performance wise, I run JB4 on map 5 and it hasn't missed a beat. Easily makes more power than straight 98 on map 2. I have no other mods. Have run a 12.5 quarter mile at Willowbank using this fuel and tune so power is excellent.

Average fuel consumption increased very slightly from 9.7 to 10.0 l/100km but filling the tank this way is cheaper than regular 91 unleaded (not that you'd do that) and it performs better than MS109 race fuel that costs over $5 per litre. I bought a 20 litre drum to use once at the drags - wont do that again since "discovering" the benefits of Ethanol enriched fuel.

I replaced a HPFP on the car BEFORE I started with E25 but 60,000k later (40k with Eflex) the current one is running strong.

What's not to like?

I agree with everything above. E85 is legit, shame it's not available at more servos though.

Originally Posted by OzJustin

Assuming you have the low & high pressure fuel pumps to support straight E85 have any of you Cobb users had a custom flash prepared to support this? (No Backend JB flashes)

I installed the Walbro Inline 255 with a new LPFP so that I could run E85 mixes. I also run meth so there's really no need for both. Unfortunately for me there's no E85 servos close to where I live so it's not that convenient for me to use, but I could see how this would work out cheaper than filling up with 98RON (unless you're tempted to use the extra power the car makes). JB4 Map 5 works just fine, I think the backend would be more useful if you wanted to run higher concentration of ethanol and squeeze out as much power as possible, in which case you would want an upgraded LPFP and an upgraded (or healthy stock) HPFP.

[dh58]

Thanks everyone. Is anyone doing it not just for what we get but because its a cleaner fuel on the environment?

[BMW86]

Originally Posted by dh58

Thanks everyone. Is anyone doing it not just for what we get but because its a cleaner fuel on the environment?

I doubt it.

I personally prefer meth injection though