Word to the wise on E85

[Stohlen]

Originally Posted by ervgotti01

Read that thread again. The engineer who was analyzing our injectors said he had problems with the filters melting at 100 Celsius when running E85. He said and I quote " As long as the temperature of the injector stays under the 100 Celsius, this engine is perferctly capable to run E85. As a matter of fact, it will run E100 without any problem under cold conditions".

There is no way in hell our injectors are running less than 100 Celsius especially since they are directly connected to the head. If the N54 was port injected I can see it not hitting 100 celsius. So please actually read the thread before posting non sense.

If there's no way in hell that the injectors are running less than 100 C, how come these injectors aren't constantly failing with normal gas? The injectors have a constant feed of cool fuel running through the filter, which means the filter (which is the furthest part of the injector from the head) is the coolest part of the injector. I'm posting MY engineering knowledge after reading the thread, thank you. You are posting what you think is happening with no data to back it up. There's no way you can conclude what happened what so ever.

Originally Posted by ervgotti01

Your improper tune theory is stupid. You can tune an engine to run perfectly on E85, but you can not tune an engine to prevent wear on hardware components ie injectors, plugs, water pump, coil packs ect ect. That's like saying if you tune an engine properly your spark plugs should not wear out. What we're looking at here is premature failure of the injectors due to E85.

Lets do the math on how an improper tune could cause problems...

Stoic of gasoline is 14.7:1. Stoic of E85 is 9.76:1. Pretty big difference. You start mixing E85 with gas at say 30% and now your ideal stoic is 13.2:1 instead of 14.7. So now your engine has no ideal that when it targets 12.2:1 for the most power, its actually running lean! And that creates more heat than your engine would see with a proper tune, it also leaves your engine prone to knocking. All of this extra heat can cause premature failure of spark plugs, injectors to melt (like these filters!), exhaust valves to cook, and in extreme cases total failure of the engine. Tuning is HUGE to engine reliability and most people don't take it seriously enough around here.

[SteveAZ]

@ervgotti01

Just like your initial post, and just as I said......you pulled out of this thread exactly what you wanted to see to support pre-conceived notion but are basing it on very little.

As I said....I don't care what you run, or about your opinion as thus far you have failed to support your "theory" with any data.

Good luck to you....

[1911A145]

Originally Posted by Stohlen

A pump is a pump. It doesn't care what kind of liquid its pumping. 5 tanks of an ethanol mix isn't going to be enough to corrode the internal seals of the pump and cause a failure. Especially because modern cars are built to tolerate ethanol to an extent (because regular gas is E10-E15.)

Now if you didn't tune for that ethanol and just threw it in your tank, and that led to a failure, that's your fault not the ethanols.

Originally Posted by SteveAZ

That's a little difficult to diagnose postmortem without a whole lot more information. i.e. logs, mods, tune info, Fuel info, car history, and which pump are you even talking about? Did you know we have more than one? If so, what else do you know about the fuel system, or the tune you were running? Did you verify your fuel, how did you come to the conclusion you were running E30? What time of year was this?

Not picking on you and sorry if it sounds like it, but these are all things you should know if you're going to start operating your car outside the manufacturers guidelines.

Of the HPFP failures that people often associate with ethanol, as to how many cases that is actually true...and then if it is, what was the real cause? The properties of ethanol or the fact that an improper tune and setup will likely have your LPFP pressures dropping dramatically and starving your HPFP? Then add in the fact that this will cause your long and short term trims to go way outside the operating limits of the DME and forcing it to take drastic measures to maintain fuel pressures but not run your engine too lean.

Simply coming on here and stating...ethanol killed my pump, injectors, girlfriend....yada, yada without providing any meaningful supporting data or facts more than likely means you shouldn't have been running it in the first place. And "because my SA said it did" doesn't cut it.

When I first started this journey and was having problems I was told my HPFP was bad numerous times by peers and tuners. That was about 10K miles ago. Guess which HPFP is in my car....the original one. How many do I have in my garage...2 additional One new one that verified it wasn't an HPFP issue, and one take off that I got for experimenting with. Only one time did I have a real failure and I don't think it can be attributed to ethanol but I can't rule it out. It was a leaky injector and the reason I went looking for it...I changed my DPs and one of them was black. I hadn't had the car for very long but I was running about E25 at the time and had been for a maybe a month or so. I then pulled the plugs and injectors and found the offender...cylinder 5 was wet. Every other problem I've had has been attributed to tune, LPFP setup, or just my own learning curve. Of those, none of them were failing parts.

Again, I'm not here to debate E85 or here with an agenda, I don't care what you run in your cars. But, if you're going to point fingers, then be prepared to back it up with data.

As I said, I am obviously a bit biased...but it's not just because I use, it's because I studied up on it. I can tell you the pro's of E85 just as well as I can tell you the con's of it from production, to properties, to usage. Obviously a lot of that information is debatable and some times it even comes down to the lessor of two evils. So again, make your own choices, but make educated ones, not...

"5 tank fulls of E30 and my stock fuel pump was toast."

or

"Those injectors are rated at 200 PSI." and "There is a recall of the programing of the fuel pump that needed to be done by BMW."

Where this guy got this I have no idea given that our rails see pressures upwards of 3000PSI...maybe he meant 200bar

and reprogramming of the fuel pump? The pump itself (impossible) as the HPFP only electrical part there is on the HPFP is the flow control valve. Maybe you mean the reprogramming of the DME to cycle the LPFP to pressurize the system when you unlock your car or open your door?

or

"E85 fuel is very dense and does not burn completely"

Really? The SG of ethanol is .787 and the SG of gasoline is .739...what do you consider "very dense"? What other characteristics of ethanol can you tell us about. How about what temperature it burns at, or its rate of atomization compared to that of gasoline since that is also what you seem to be quoting. Hint, there is a reason methanol (also an alcohol) is used for CP injection.

or

"Indeed, it is a fuel that corrodes rubber"

True, but can you tell us how much rubber we have in our fuel system or what materials our fuel system consists of?

or

"Ran 30/70 e85/93 for 2 or 3 months had to replace:
1 LFPS
12 plugs
6 injectors
Just sayin

DPs FMIC JB4 ISO"

I don't even know what an LFPS is...not even going to touch this one

To the both of you...

I was talking about my factory, LPFP. I am running COBB's E30 mapping, with E30 fuel (confirmed) and had zero issued on my logs and all supporting mods.

This was even confirmed by COBB's engineer himself about the LPFP issue and ethanol. It is hit or miss. I never said anything else failed. Others have. I love E-85 mixes on our cars, but after my experience on my third LPFP now, I will stick to 93 oct. which hasnt given me any issues to date.

BTW, a LPFS = Low Pressure Fuel Sensor on the fuel rail right next to the HPFP.

[SteveAZ]

Originally Posted by 1911A145

To the both of you...

I was talking about my factory, LPFP. I am running COBB's E30 mapping, with E30 fuel (confirmed) and had zero issued on my logs and all supporting mods.

This was even confirmed by COBB's engineer himself about the LPFP issue and ethanol. It is hit or miss. I never said anything else failed. Others have. I love E-85 mixes on our cars, but after my experience on my third LPFP now, I will stick to 93 oct. which hasnt given me any issues to date.

BTW, a LPFS = Low Pressure Fuel Sensor on the fuel rail right next to the HPFP.

That's fair...other manufactures that spec e85 for their vehicles, use a specific LPFP and you may be right. Sounds like you had bad luck with your LPFPs, were you running the stock ones? If there is a weak point that I would worry about the most...its the lpfp as we don't know the affects of e85 on it but an e85 spec'd LPFP requires modification of the LPFP bucket.

BTW...an LPFS may be a Low Pressure Fuel Sensor but what is an "LFPS"? and how the heck could e85 be blamed for that?

[flinchy]

Originally Posted by ervgotti01

Read that thread again. The engineer who was analyzing our injectors said he had problems with the filters melting at 100 Celsius when running E85. He said and I quote " As long as the temperature of the injector stays under the 100 Celsius, this engine is perferctly capable to run E85. As a matter of fact, it will run E100 without any problem under cold conditions".

There is no way in hell our injectors are running less than 100 Celsius especially since they are directly connected to the head. If the N54 was port injected I can see it not hitting 100 celsius. So please actually read the thread before posting non sense. There are plenty of times when you drive when cruising foot off the accelerator that fuel is not being injected, which leads to the fuel not being cycled through to cool the injectors. Or how about say after an hour drive operating temp at 240 F you shut down the car? Those injectors are no longer cycling fuel and those injectors will sit there and bake.

As far as your other statement, Can I be 100% E85 caused this? No. Can you Be 100% will not cause this? No. With the engineer stating that E85 at 100 Celsius can cause injector failure it is likely that you can have a catastrophic of multiple injecotrs as they will all be operating at the same temperature + or minus a couple of degrees.

Your improper tune theory is stupid. You can tune an engine to run perfectly on E85, but you can not tune an engine to prevent wear on hardware components ie injectors, plugs, water pump, coil packs ect ect. That's like saying if you tune an engine properly your spark plugs should not wear out. What we're looking at here is premature failure of the injectors due to E85.

Except due to evap, e85 runs cooler than unleaded so your argument proves that e85 is safe

Because it is safe, ffs guys.

Ed: and why would you keep replacing stock lpfp? Just get an upgraded one (or at least an inline to lessen the load

And why and how would the lpfs be on the fuel rail which has high pressure fuel? :/

And if you keep replacing plugs to factory specs ... And you're highly tuned... Yes you'll have to replace them. Go 1 step colder gapped for a reason.

Plugs struggling will also lead to dead coils due to more load...

Seriously, everything going wrong here seems to be a problem going wrong between the car and the person driving the car...

And lastly (for now)... Ethanol does not eat rubber.. It's less corrosive than unleaded... What it does.. Is hold water

If you have old ALREADY WORN rubber, that has some water in it in the cracks... The ethanol absobs that water and cracks the rubber further - this is called dry rot

Ok we learnt something now?

[Murph335]

For a track day why not just mix in 100 oct instead of messing with E85!!??

I can see where E85 would be cool for a DD solution but not at the cost of part failures!

[Freon]

Originally Posted by Stohlen

Lets do the math on how an improper tune could cause problems...

Stoic of gasoline is 14.7:1. Stoic of E85 is 9.76:1. Pretty big difference. You start mixing E85 with gas at say 30% and now your ideal stoic is 13.2:1 instead of 14.7. So now your engine has no ideal that when it targets 12.2:1 for the most power, its actually running lean!

Oxygen sensors don't know the difference between E85 at 9.76:1 and gasoline at 14.7:1, or E30 at 13.2:1 (or whatever). They read lambda, or simply the ratio above or below stoic. "AFR" is something tacked on to the oxygen sensor data after the fact by multiplying by a guessed/fixed number (ex. 14.7 for gasoline). If you put an aftermarket gauge set for 14.7:1 onto a car running E85 that was running at 9.76:1 AFR, it would read 14.7:1. It doesn't know any better, and neither does your car's ECU. It just knows you're running lean or rich and tries to trim fueling to fix the problem and meet a lambda target. "AFR" is a huge misnomer. It's just a transform to make it look pretty for humans who think "AFR" is how engines and ECUs think, but they do not!

So, the ECU certainly DOES have an idea as it uses the oxygen sensors to trim fuel. It should complain (i.e. throw a CEL) if your gasoline content is off too much and it has to trim more than is "acceptable". Pretty much any car with oxygen sensors will try to trim fuel to some extent, and here in the states even pump 87 can have 0% to 10% ethanol content. Newer cars are extremely savvy with it and store all sorts of various fuel trims for different situations.

[Stohlen]

Originally Posted by Freon

So, the ECU certainly DOES have an idea as it uses the oxygen sensors to trim fuel. It should complain (i.e. throw a CEL) if your gasoline content is off too much and it has to trim more than is "acceptable". Pretty much any car with oxygen sensors will try to trim fuel to some extent, and here in the states even pump 87 can have 0% to 10% ethanol content. Newer cars are extremely savvy with it and store all sorts of various fuel trims for different situations.

The ecu will adjust to the new AFR, but it can't and won't adjust far enough because of the great difference in target AFR. It can only adjust so much and will run you lean. That's the whole point. Yes O2 sensors read the amount of fuel in the exhaust and use that for targets, i never said they didn't. But its much easier to describe in terms of calculated AFR.

[SteveAZ]

So to clarify for those reading this and going...WTF? Very quickly and not too in depth...

Our oxygen sensors are reading lambda as was said. At idle/cruise the goal is to burn all the fuel for economy and emissions. When this is achieved we get a lambda value of 1.0 which is basically just a correlation to a voltage value fed back from the O2 sensor.

With gasoline, to achieve this we have to start with approx. 14.7 grams of air and 1 gram of fuel at the beginning of the combustion process. Thus a value of 14.7 is assigned in the software...i.e. JB4, Cobb...whatever.

For a true E85, in order to reach that Lambda target of 1.0 we start with a mixture of 9.8 grams of air to 1 gram of fuel. Since the software is programmed that a lambda of 1 = 14.7, our software still reads 14.7 even though it is really 9.8 which is really 1

So, when you go and put E85 in your tank and the DME is trained/programmed to tell the injectors to spray at a rate of 14.7 to 1, when in reality you need to be spraying at 9.8 to 1...guess what happens....you run very lean but the DME quickly adjusts thanks to the O2 sensors.

However, the DME can only adjust so much (unless properly tuned) and as you can see with E85 you need to spray a lot more fuel. Once outside the DME's limits and it can no longer spray enough fuel, you quickly run lean. When you do so your cylinder temps rise...blah blah blah at which point you get detonation (fuel igniting with no spark and at the wrong times) and if you're the OP, you melt your injector filters, but only enough that you can't run E85 and they still flow gasoline just fine...or is it that with E85 he was running too lean and misfiring J/K...who knows what he did and most importantly...neither does he so take the "Word to the wise" portion of this thread title with a grain of salt.

[135Pats]

Originally Posted by SteveAZ

So to clarify for those reading this and going...WTF? Very quickly and not too in depth...

Our oxygen sensors are reading lambda as was said. At idle/cruise the goal is to burn all the fuel for economy and emissions. When this is achieved we get a lambda value of 1.0 which is basically just a correlation to a voltage value fed back from the O2 sensor.

With gasoline, to achieve this we have to start with approx. 14.7 grams of air and 1 gram of fuel at the beginning of the combustion process. Thus a value of 14.7 is assigned in the software...i.e. JB4, Cobb...whatever.

For a true E85, in order to reach that Lambda target of 1.0 we start with a mixture of 9.8 grams of air to 1 gram of fuel. Since the software is programmed that a lambda of 1 = 14.7, our software still reads 14.7 even though it is really 9.8 which is really 1

So, when you go and put E85 in your tank and the DME is trained/programmed to tell the injectors to spray at a rate of 14.7 to 1, when in reality you need to be spraying at 9.8 to 1...guess what happens....you run very lean but the DME quickly adjusts thanks to the O2 sensors.

However, the DME can only adjust so much (unless properly tuned) and as you can see with E85 you need to spray a lot more fuel. Once outside the DME's limits and it can no longer spray enough fuel, you quickly run lean. When you do so your cylinder temps rise...blah blah blah at which point you get detonation (fuel igniting with no spark and at the wrong times) and if you're the OP, you melt your injector filters, but only enough that you can't run E85 and they still flow gasoline just fine...or is it that with E85 he was running too lean and misfiring J/K...who knows what he did and most importantly...neither does he so take the "Word to the wise" portion of this thread title with a grain of salt.

Well put.

[Grip&Go]

yea I had 50k on the OEM plugs so I just replaced those because it was time.
I brought the ones from BMS. 11.74ea.When the car was at bmw they said those were after market and no CPO work/injectors would be warrantied because those are aftermarket so i'd need to replace those with BMW's ones that Bosch makes witch are the same ones from the BMS website. so that was a new set of 6 for $140 FML

Originally Posted by SfValley335i

You swap spark plugs twice within 3 months??!!

Who advised you of that? I think its nearly impossible to foul plugs in a months worth of driving (1500 miles?)

I've been running e85 mix (minimum of 5 gallons) in my car for 10 months now, I daily drive my car. No issues.

I think some of you guys having issues with e85 is because your car wasnt in prime condition. Similar to some people that get tuned and start getting fault codes and blame the tune, not the condition of their motor.

[JZWBMW]

Originally Posted by n54door

Indeed, it is a fuel that corrodes rubber (seals and lines), leaves a sticky residue, and has not been fully tested with our platform (and many other auto's), but what can be concluded about the cause/effect of 3 injectors going out at once as a result of using E85 fuel?

I would imagine many would be reporting similar incidents, but this is the first one I've seen where someone is linking injector failure to e85 fuel.


That said - I have some experience with E85 from my previous performance vehicle, and I can tell you, it is a very risky fuel to use to say the least.

My injectors were gummed up at the injector tips from the e85 residue and carbon/oil vapors mixing and building up. They looked like solid black drops hanging off the injector tips. It eventually caused a lean condition and popped my engine. I wonder if this is the case here.

I have seen the black goo too, I just run a tank of gasoline every so often and that will clean them right up in my experience :-)
JZW