[Glowin]

I'm running Cobb 2+ Aggressive maps on my car, with 94 Octane that's got no ethanol in it. I've got an 2008 MT 335. During the 3rd gear WOT pulls, I see some timing drops of a few degrees. When I've added some octane booster, like Lucas, the drops go away.

Would adding some E85 to regular gas get rid of my timing drops? I've read here quite a few say it's got higher octane. I'm not totally sure because of the Wikipedia article that says it's only around 94 to 96 octane.

E85 has an octane rating higher than that of regular gasoline's typical rating of 87, or premium gasoline's 91-93. The Renewable Fuels Foundation states in its Changes in Gasoline IV manual, "If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual-octane engine tests."

So would my plan work? Or should I just stick to half a bottle of octane booster with each tank?

[tc535i]

yeah, it should. Try ~30%

btw... let me know where you get it. Considering a move to Bellevue in the next year or so from LA and the 335i will definitely be coming with!

[CHECKERED]

Originally Posted by Glowin

Would adding some E85 to regular gas get rid of my timing drops? I've read here quite a few say it's got higher octane. I'm not totally sure because of the Wikipedia article that says it's only around 94 to 96 octane.

the effective octane of E85 is higher than 96 because the article does not take into account the cooling effect of spraying a bunch load of extra fuel specifically on a boosted application where pressurized and cold charged air is King.

just like water injection, water does not burn and should in theory cause a loss of power, but the opposite is true where a small spray of even 100% water will net more power by cooling the charged air and reducing combustion temperatures for the next cycle

Use octane booster or meth injection, E10-E15 will not solve your problem you would need to got to E30

[proTUNING Freaks]

Unless you upgrade your in-tank fuel pump you should stick with an E30 mix. You can use the OTS E30 map. Feel free to shoot over some datalogs for review to us at any time and I'd be happy to review them and provide feedback.

Dzenno@PTF

[Welterweight]

How do you know you are having timing drops

Can you feel it? Or seeing it through logging?

THanks!

[Glowin]

I know I can run E30 maps with Cobb, but my question is what if I just wanted to still run the Stage 2+ maps? What mix would I have to run not to get drops of a few degrees?

The reason I ask is also because I have another N54 car that's Cobb tuned, but is Stage 1, so I can't run E30 maps on that one. So I wanted to know how much E85 might be helpful in general on top of regular gas to stop timing drops. I was hoping a couple gallons would do, that way, I can keep some E85 at home and after every fill up, top it up a bit.

But if I have to go an E10 mix or higher on it, then it's just simpler to add half a bottle of Lucas each time, cuz I want to avoid filling up at two stations each time (the station I go to just has regular and E85). The problem with that though is I'm not a huge fan of doing it all the time as I'd read it's not that great for the engine and leaves orange deposits on everything including the plugs.

In which case, it would suck, as I'd have to go down to Sport maps it sounds like.

@Welterweight - yes, I'd logged and discovered that. You can search for my posts on it and see my datazap logs.

@Dzenno - thanks for the offer. I'll take you up on it most likely soon, and I want to get my car protuned next. I'm running OTS E30 maps on it right now, but haven't gotten around to logging yet.

[Jeff@TopGearSolutions]

I would stay with adding E85, probably 30% or a little less. I think you will have to experiment unfortunately as every car is different.

I would stay away from the octane booster because as you said over the long term it leaves deposits.

[335NJ]

Originally Posted by Jeff@TopGearSolutions

I would stay with adding E85, probably 30% or a little less. I think you will have to experiment unfortunately as every car is different.

I would stay away from the octane booster because as you said over the long term it leaves deposits.

X2, dump in to get a 25-30% mix and datalog to confirm trims and fuel pump are looking good, then more can be added up to about E40 without needing an upgraded pump, and backend flash.

I run about a 40% blend with 93 constantly with no problem, and it reall woke the car up.

[Miko226]

e85 =

[Glowin]

I was hoping to just figure it out without more logging, but I might just have to do that.

I didn't think you can run an E30 mix though on regular OTS maps, especially Stage 1?

And you won't take advantage of the E30 if you aren't tuned for it (by either using the OTS E30 maps for stage 2+ cars or getting protuned for Stage 1 on E30)

[tke344]

Running a low concentration of Ethanol (~30% or less) should be fine without adjusting the fuel scalar, the car can compensate on it's own. Of course adjusting it is preferred to keep trims close to zero. Log STFT after throwing in a few gallons, +34 is the max the car will adjust, so you want to be under that or risk running lean, I wouldn't feel comfortable going much above 20 though. It's very easy to fix in the ATR software though.

[proTUNING Freaks]

In most cases going past E25 you'll set off fuel trim codes eventually with a higher powered tune like the Stage 2+ Agg so E20 I'd say is about the max you'll be able to do without running into fuel trim codes. It'll vary from one car to another based on many factors.

[Spoolin1]

Is there an OTS ethanol map for stage 1+ or can one be used instead of the stage 1+?

[Jeff@TopGearSolutions]

Originally Posted by Glowin

I was hoping to just figure it out without more logging, but I might just have to do that.

I didn't think you can run an E30 mix though on regular OTS maps, especially Stage 1?

And you won't take advantage of the E30 if you aren't tuned for it (by either using the OTS E30 maps for stage 2+ cars or getting protuned for Stage 1 on E30)

You can add E85 to your fuel on any map. Will it take full advantage of maximum output without appropriate tuning, no. Will adding E85 to your fuel increase octane, yes. You can even do race gas for an octane bump on any map.

I believe the goal of you adding octane booster was to increase octane so I don't see why adding E85 to your fuel to increase octane doesn't make sense.

It seems you want to add ethanol blindly, reap the benefits of e85 octane and have maximum output, not going to happen.

You will need to log your vehicle to do this right otherwise go back to a less aggressive map. Your vehicles datalogs are the heart monitor of your vehicle, it shouldn't be taken lightly.

[Glowin]

Originally Posted by Jeff@TopGearSolutions

You can add E85 to your fuel on any map. Will it take full advantage of maximum output without appropriate tuning, no. Will adding E85 to your fuel increase octane, yes. You can even do race gas for an octane bump on any map.

I believe the goal of you adding octane booster was to increase octane so I don't see why adding E85 to your fuel to increase octane doesn't make sense.

Right, thanks for confirming that. To refresh your memory, I get timing drops (so I do log) of a few degrees on the Aggressive maps, even on 94 (no ethanol) Chevron, which disappear once I add octane booster.

Rather than doing that all the time, I was just asking if A) my theory was valid that I could add E85 instead to get rid of the timing drops, which you have confirmed, and B) what people's guess would be as to how much I might need to add to a tank. Sounds like I'll have to experiment to see what E blend will work for me and log it.

Originally Posted by Jeff@TopGearSolutions

You can add E85 to your fuel on any map. Will it take full advantage of maximum output without appropriate tuning, no.

It seems you want to add ethanol blindly, reap the benefits of e85 octane and have maximum output, not going to happen.

Huh? Where did I ever say I wanted to get max output? I'm not interested in anymore output. I even said that I know without tuning the OTS maps, I won't get any more power, which I'm fine with. Read above as to my goals, stated in the first post.

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Related to the above, would protuning Stage 1 maps for E30 yield any more power, and if so, what would be the guess as to how much?

[Jeff@TopGearSolutions]

Originally Posted by Glowin

Right, thanks for confirming that. To refresh your memory, I get timing drops (so I do log) of a few degrees on the Aggressive maps, even on 94 (no ethanol) Chevron, which disappear once I add octane booster.

Rather than doing that all the time, I was just asking if A) my theory was valid that I could add E85 instead to get rid of the timing drops, which you have confirmed, and B) what people's guess would be as to how much I might need to add to a tank. Sounds like I'll have to experiment to see what E blend will work for me and log it.



Huh? Where did I ever say I wanted to get max output? I'm not interested in anymore output. I even said that I know without tuning the OTS maps, I won't get any more power, which I'm fine with. Read above as to my goals, stated in the first post.

-----------------------------------------------------

Related to the above, would protuning Stage 1 maps for E30 yield any more power, and if so, what would be the guess as to how much?

As I mentioned from the beginning you will need to experiment with E85 and the dosage should you want to find out the minimum required to keep your ignition timing in check.

I would stay with adding E85, probably 30% or a little less. I think you will have to experiment unfortunately as every car is different.

And you won't take advantage of the E30 if you aren't tuned for it (by either using the OTS E30 maps for stage 2+ cars or getting protuned for Stage 1 on E30)

Here is where it seemed suggested you are referring to max output gains as I have no other interpretation of "advantage" other then max output. You also suggested that there is no advantage to E30 if you are not tuned for it which would be incorrect as it does add octane, which can be an advantage to some.

If you are simply referring to an octane increase then adding some E85 will result in an octane benefit, which may be an advantage too.

Related to the above, would protuning Stage 1 maps for E30 yield any more power, and if so, what would be the guess as to how much?

My guess is 10-15WHP but you already said above your not interested in anymore output.

Sorry to nit pick every detail but you are all over the place as to what you are looking for, I'm just trying to get the story straight and help.

[mike@x-ph.com]

I defintely recommend that you add e85.
Just like everyone said above stick with E30

[007_e350]

I've tried that I can affirm the timing corrections go away - the only down side is addiction

... I got so addicted my hpfp went out, bmw still covers it till 120k I believe ... & they test fuel to replace under warranty, I had to suck out and put in 93 to reduce e85% lol

[Glowin]

Thanks Jeff for your help.

Sorry if it seems I'm all over the place, but as I said in my OP and the subject of my thread, I am just trying to get rid of the timing drops.

For another 10-15 WHP, I probably won't Protune my E61 Stage 1 car's Cobb maps for E30 gas. I will save that for my Stage 2+ 335.

[Jeff@TopGearSolutions]

Originally Posted by Glowin

Thanks Jeff for your help.

Sorry if it seems I'm all over the place, but as I said in my OP and the subject of my thread, I am just trying to get rid of the timing drops.

For another 10-15 WHP, I probably won't Protune my E61 Stage 1 car's Cobb maps for E30 gas. I will save that for my Stage 2+ 335.

I'll stick with my original response then, E30. You may be able to get away with a little less but I wouldn't bother trying to get it down to the last oz.

Once you are running E30 you should check your Low pressure fuel pressures too just to make sure those are in check.

Assuming your ignition timing is at par you won't need to datalog anymore

[Spoolin1]

Essentially you will make more power by upping the octane and not changing the tune IF currently on 94 octane, timing is being pulled. The timing being pulled means you're losing some power also and the added octane will recoup that power loss. You'll basically be getting the max power out of the tune that's possible with the added octane.

[Glowin]

Thanks, y'all!