[Crewchief05]

What map should I use with 93+ E85? Would this just be aggressive? I saw 100 octane (race maps) but no e85 mix. Also this may be a dumb question but do I need any further mods to run e85? I am currently running St 1+ soon to be 2+. Do you literally just fill from the gas station or mix seperate? If I do not need any further mods or crazy mixing methods then e85 will be in the tank asap

[enrita]

Originally Posted by Crewchief05

What map should I use with 93+ E85? Would this just be aggressive? I saw 100 octane (race maps) but no e85 mix. Also this may be a dumb question but do I need any further mods to run e85? I am currently running St 1+ soon to be 2+. Do you literally just fill from the gas station or mix seperate? If I do not need any further mods or crazy mixing methods then e85 will be in the tank asap

the E30 map but you need to be fully bolt on. you mix it at the gas station, there is a pdf guide on cobb site and also a dedicated cobb E30 thread here, just search for it.

[135Pats]

Any thoughts on my log? Stg2+ agg...i'm not wild about the noisy cyl2, and the modest timing pull approaching peak boost. Any thoughts would be appreciated, the car feels strong and hasn't thrown any codes in quite some time. Just curious as to what you guys think, thanks! Oh and to be clear, download the google doc so you can see all the values.

https://docs.google.com/file/d/0B0DO...it?usp=sharing

[Ænema]

That's a pretty good log. It's completely normal to see one or two cylinders make a small correction like that, especially at/near peak torque. I wouldn't even pay attention to the correction in #6, that happened before you were even at WOT.

The only thing is that you're seeing some pretty mild overboost induced throttle trimming, you could clean that up a little if you want to.

[135Pats]

Originally Posted by Ænema

That's a pretty good log. It's completely normal to see one or two cylinders make a small correction like that, especially at/near peak torque. I wouldn't even pay attention to the correction in #6, that happened before you were even at WOT.

The only thing is that you're seeing some pretty mild overboost induced throttle trimming, you could clean that up a little if you want to.

Thanks for the response, I agree with all of your comments...Cyl 6 didn't worry me, and all in all the corrections are pretty modest, it was the sleight pull in timing that piqued my interest. Any thoughts on correcting that throttle trimming? I'm pretty competent on our cars, but I have very little experience with ATR, i've only used OTS mapping. I plan on getting protuned in the spring, so I may just accept it as being less than 100% until then if the logs still look relatively clean. Pushing 19psi is a bit more than i'd like (though taper looks strong), though last I checked my snails were in very good chape.

[135Pats]

Also I just want to say...Cobb fueling FTW. Pins AFRs perfectly every time, that makes me a happy camper.

[Ænema]

Originally Posted by 135Pats

Thanks for the response, I agree with all of your comments...Cyl 6 didn't worry me, and all in all the corrections are pretty modest, it was the sleight pull in timing that piqued my interest. Any thoughts on correcting that throttle trimming? I'm pretty competent on our cars, but I have very little experience with ATR, i've only used OTS mapping. I plan on getting protuned in the spring, so I may just accept it as being less than 100% until then if the logs still look relatively clean. Pushing 19psi is a bit more than i'd like (though taper looks strong), though last I checked my snails were in very good chape.

http://www.e90post.com/forums/showthread.php?t=792736
I started that thread a while back and there's some good discussion in there on fixing overshoots.

Honestly though, once the temps start to warm up(charge air becomes less dense) your overshoots may fix themselves. The DME uses calculated MAF to measure load and it uses the WGDC base to hit that MAF. When it's cold the air is "heavier" so it takes less WGDC to hit target and it overboosts before the PID table can pull out DC.

[WesleyC]

Just making sure that I understand this chart correctly...



I would need to mix ~11 gallons of gasoline and ~5 gallons of E85 to get E33.

Is it ok to add a little more E85 just to be safe? I don't want to use the E30 map and not blend in enough E85.

I cannot tell what kind of gasoline that chart is assuming (100, 93, 91). I only have access to 91 so would I need to mix in even more E85?

Thanks,
Wes

[Ænema]

Yes, you're correct. The general rule of thumb is 5 gallons of e85 to a tank. However, the tank only holds ~14 gallons so it's more like 5 gallons to 9 gallons. Also, right now e85 is in a "winter blend" so it is almost certainly less than e85. The DME is able to compensate for a fairly wide range of ethanol content, so it's by far better to have more ethanol than not enough.

Keep an eye on your timing and STFTs in your logs. If timing is clean and fuel trims are good then you're fine. If not, adjust ethanol content and fuel scalar if necessary.

EDIT: Ohh, if you start approaching or exceeding roughly a 40% mix then add LPFP actual to the log list, you want to be sure you're not killing the pump.

[335i_sleeper]

Originally Posted by Ænema

Yes, you're correct. The general rule of thumb is 5 gallons of e85 to a tank. However, the tank only holds ~14 gallons so it's more like 5 gallons to 9 gallons. Also, right now e85 is in a "winter blend" so it is almost certainly less than e85. The DME is able to compensate for a fairly wide range of ethanol content, so it's by far better to have more ethanol than not enough.

Keep an eye on your timing and STFTs in your logs. If timing is clean and fuel trims are good then you're fine. If not, adjust ethanol content and fuel scalar if necessary.

EDIT: Ohh, if you start approaching or exceeding roughly a 40% mix then add LPFP actual to the log list, you want to be sure you're not killing the pump.

Really thats weird my tank hold 16 gallons...

[Ænema]

Originally Posted by 335i_sleeper

Really thats weird my tank hold 16 gallons...

Really? I've never been able to get more than just over 13 gallons in my car when reading ~15 miles to empty. Maybe the e8x and e9x use different size tanks?

[335i_sleeper]

Originally Posted by Ænema

Really? I've never been able to get more than just over 13 gallons in my car when reading ~15 miles to empty. Maybe the e8x and e9x use different size tanks?

Most likely i filled my car up once almost bone dry 3 miles left and the pump read 16.4 gallons. Most likely they had to put a smaller tank in the e8x because of its limited space.

[135Pats]

My E8x tank has never seen over 13 gallons, when I run it pretty damn close to empty it takes about 12.5ish. FWIW.

[Ænema]

Sounds like there are definitely two different size tanks. Good to know.

[WesleyC]

Originally Posted by Ænema

Sounds like there are definitely two different size tanks. Good to know.

Yea, there must be. Your first post confused me! My tank definitely holds 16 gallons.

Can anybody with a 335i tell me how much E85 they add? According to the chart, it should be roughly 5 gallons of E85 to 11 gallons of gasoline, but if you are using 5 gallons of E85 to 9 gallons of gasoline, I should add more E85? Maybe 6 gallons of E85 and 10 gallons of gasoline?

[WesleyC]

One more thing... I live about 10 miles from the nearest E85 station. Should I fill up and then flash my car with the E30 map or can I flash the car first and then fill up?

A very dumb question, I know. Please be gentle!

[SfValley335i]

Originally Posted by Wesley Crusher

One more thing... I live about 10 miles from the nearest E85 station. Should I fill up and then flash my car with the E30 map or can I flash the car first and then fill up?

A very dumb question, I know. Please be gentle!

Fill up then flash at the station...

[WesleyC]

Originally Posted by SfValley335i

Fill up then flash at the station...

That's what I was afraid of. Too bad flashing takes 10-15 minutes.

[enrita]

Originally Posted by Wesley Crusher

That's what I was afraid of. Too bad flashing takes 10-15 minutes.

are you using some kind of custom flash? takes 1 minute for me to flash from OTS to a modified ATR map

[SfValley335i]

Originally Posted by Wesley Crusher

That's what I was afraid of. Too bad flashing takes 10-15 minutes.

Going from Stock to a modified rom/flash does take 15mins or so. But if your going from a stage 1 flash to a e30 flash, it takes 5mins or less.

[WesleyC]

Originally Posted by enrita

are you using some kind of custom flash? takes 1 minute for me to flash from OTS to a modified ATR map

Originally Posted by SfValley335i

Going from Stock to a modified rom/flash does take 15mins or so. But if your going from a stage 1 flash to a e30 flash, it takes 5mins or less.

Ah, got it. That makes sense.

Thanks, guys.

[WesleyC]

Back from the gas station. I filled up with 6 gallons of E85 and the rest with 91. Flashing the car to the E30 map took a minute, maybe two.

When I started the car, the idle was jumping around, but I figured the fuel was just mixing. It took a good five minutes for the idle to settle down, but I just waited. I didn't want to take a chance.

My initial impression is WOW! Going from S2+ Sport to the E30 map made a huge difference. The car pulls super hard, but at the same time very smoothly. I am very, very impressed.