[connerry330i]

I saw mention made in the JB4 thread about E85 blends (E20 blended) ...curious if anyone has tried this on a stock M35i engine.

I ran blended E30 on my old X1 35i with the N55 without an issue, but that was to get up to 93 octane when I was living in San Diego. It's hotter than shaved yak nuts here in Dallas, so I'm thinking of running an E20 blend here stock. Any experience/input greatly appreciated.

[rice_rocket88]

I'm in on this thread just to see if/when anyone does this. I'm lucky to have higher octane at the pump to start off with, but no E85 stations within reason to my commute to even bother trying to mix for higher.

[xcelir8bmw]

Hi. Will the stock fuel pump be able to support a higher flow rate for E85 and what about a tune?

On my prior STi I was getting some mad numbers with new pump and Tune.

[connerry330i]

Originally Posted by xcelir8bmw

Hi. Will the stock fuel pump be able to support a higher flow rate for E85 and what about a tune?

On my prior STi I was getting some mad numbers with new pump and Tune.

No idea, but we're not talking full E85, more a blend of it and 93 octane to get E20-E30. This supposedly is a)safer all around and b) should result in a bump in power,even stock, although just how much is unclear. But the engine, fuel pump etc should handle E20-E30 stock without a problem. I'll probably try it this weekend, when I have time to drive around a bit.

As far as a tune goes...considering a JB4 a little later on...I'd prefer a flash tune but who know when that's gonna happen.

[connerry330i]

Finally found E85 a few miles close to home, and am running 3.1 gallons mixed with a full tank of 93 octane. (Also learned Texas had 88 Octane E15...never heard of it! Thanks California!)

Anyway, according to a few calculators, that blend results in E24, (E24.45 for the tragically pedantic) or 94 octane. According to the BMW manual, we can run these wee beasties safely up to E25/95 octane.

What does the butt dyno say?...not a damn thing, I've only driven six miles since, FFS. Planning on a few early morning drives though to see if I notice anything worth sharing. If so, I will.

[billnchristy]

Yeah I had done the math and figured on about 1 octane point as well. It might run cooler though, and that could be worth it.

The way a Ford ecoboost is programmed, I bet you would feel it. I could not believe the difference between mid grade and premium with it, never felt any different in a bmw.

[connerry330i]

Originally Posted by billnchristy

Yeah I had done the math and figured on about 1 octane point as well. It might run cooler though, and that could be worth it.

The way a Ford ecoboost is programmed, I bet you would feel it. I could not believe the difference between mid grade and premium with it, never felt any different in a bmw.

You know, when I did this before with my old E84 N55, I definitely felt a significant difference, because I was living in San Diego at the time and well...that CA gas is a$$, for lack of a better term.

That was stock, and then later even better performance differences with a Dinan Stg 2 tune, which we all already know is the case with any tuned vehicle. I can say this: so far, I believe there's a slight uptick in the mid-range.

When I drove the X2 from SD to Dallas in May when we relocated, my thoughts then were the M35i stock was about as powerful as the tuned E84 N55, but definitely less so than the stock F30 B58 that I retired for it. There are passing maneuvers I would pull off with the F30 that I wouldn't ever consider with the other 2 vehicles. After a bit of running around yesterday, there's definitely some more spirit in the mid-range.

FYI I've only driven the car in Comfort since the blend. Today I have to do a bit of freeway driving, so I'll do that run in Sport either up or back and see if there's anything worth crowing about.

[rice_rocket88]

Great info.. my 2 cents compared to my N54: X2 m35i is faster off the line, but after about 70-80 the N54 keeps on pulling like a freight train, the X2 kind of pitters off. Still it's quick by normal standards for sure though! I'm blessed to have good gas here so I can't comment on E85 blending.

[billnchristy]

That’s funny because I feel like the interstate overtake is a strong suit of this car, especially in sport sport.

I’m frankly shocked that accelerating to pass generally leads to 90+. I usually get out of throttle at the car being passed rear fender now.

[rice_rocket88]

The x2 is light and a fast turbo spool that digs high revs.. But the n54 has two turbos and larger displacement so it doesn't run out of steam. My e60 was also a little further from stock so it generated more power for sure. I have a big onramp on my way to work where people are generally coming up at 75mph +. I get the chance to give the car a nice big stretch to merge in and since it's every day I can compare the two cars back to back..

[connerry330i]

Originally Posted by billnchristy

That’s funny because I feel like the interstate overtake is a strong suit of this car, especially in sport sport.

I’m frankly shocked that accelerating to pass generally leads to 90+. I usually get out of throttle at the car being passed rear fender now.

If you ever get a chance to drive a car with a B58 in it, jump on it. Of the 3 forced induction BMW's I've been blessed to own, it was the only one I felt had too much power for the street.

I know...weird flex, right? Especially in this day/age of " 'moar power, vicar?" but seriously, I never once thought that 340i needed more power. It was perfectly insane. What it NEEDED was a better suspension calibration. I tried with Dinan Shockware, and it helped immensely, but I chose the car because of the LCI suspension revisions and the "Track Package"/MPSS tire setup of the day and still felt the need to tune the adaptive dampers.

And that opinion was solidified in March 2018, when I went to Thermal in Palm Springs for the BMW One Day performance driving school. We drove F30 340i's with Track and M240i's. I gained appreciation for learning better car control of my own vehicle, sure, but I also left the event trying to figure out how to convince my wife I had to dump the F30 for a smaller 2 door 6 months into ownership.

Didn't work, obviously, but I tried

[billnchristy]

I’ve driven an m240i with it. I tend to agree though, there’s a guy who goes to work around the same time as me and that things a rocket.

I think the m35i is about the perfect power level, especially if throttle lag could be fixed.

[billnchristy]

I threw 3 gallons of 104 octane e85 in today and topped off with 93. Calculator says 95 octane and 25%. Not sure if this is too much but she feels peppy.

[rice_rocket88]

Who knows, the computer might actually add a little boost, certainly it could advance timing a little.

[connerry330i]

Originally Posted by billnchristy

I threw 3 gallons of 104 octane e85 in today and topped off with 93. Calculator says 95 octane and 25%. Not sure if this is too much but she feels peppy.

Sorry, it's been a bit since I updated, but last week I refilled with a mix that came out to the same ratio, and it definitely is noticeable, but again mainly in the midrange. The engine still goes off a cliff after 5800 RPM but it's more rolling down a slope now vs. Bond skis off the mountain in 1977.