E85 or 93+Methanol tunes for the track (road course)

B8 S4
#21

e85 isn’t a very dependable fuel.

Even if you go to the same gas station, the percentage of actual ethanol varies greatly, in fact it is rarely ever 85%, its usually much lower.

And as Justin mentioned, e85 is an alcohol which makes it hygroscopic, the longer it sits in an environment where it is exposed to air, it will absorb the moisture in the air and basically ruin itself.

If you want to run e85, get an e85 testing kit so you know what percentage you are using, and don’t store it, just refill at the gas station as needed.

#22

Thanks for the input. And point taken that you should expect varying ethanol content. I’ve actually been emailing with the management of my local station to try and get more info about their supply, we’ll see what they say. The first response said it’s always 85% ethanol but I’m looking for more info than that.

Regarding storage, I absolutely would not store any with the exception of filling jugs on the way to the track and using them completely that same day.

#23

I am picking up on the sentiment of approach cautiously here, duly noted. I’m still researching things and there aren’t any tune options I would consider at the moment anyway. Hopeful APR or GIAC will bring something to the table. Also researching race gas availability in my area.

#24

So after digging a bit further, the corporate reps for my local service station got back to me and pointed me to an ASTM paper (D5798-11 for reference) that details the E85 blend specification and classes in the U.S.

It’s repeated in part here:
http://www.afdc.energy.gov/fuels/ethanol_e85_specs.html

And yes, you’re reading that correctly, 51-83% ethanol content, no guarantees across all classes, the ASTM article does note the class changes by state and time of year but the class does not dictate the ethanol content. No guarantees of what you are getting … how could you possibly tune for this?

Everyone’s comments are making a lot more sense now, thanks all!

#25

I blame the Koch brothers.

#26

For some reason I can’t get E85 off my mind. I’ve contacted all of the tuners I can think of to see who all is planning an E85 tune, get their thoughts, and to see how they plan to handle varying ethanol content among fuels.

I will say that upon further research high ethanol content fuels do seem to be prevalent (at least in Texas), despite the open book E85 specification. My theory on why this is the case is simply that the ethanol is cheaper than gasoline, such that it just makes sense economically to sell high ethanol E85.

Latest from the tuners:

APR - E85 tune in development, no ETA, have a plan to handle varying ethanol content, rumored stage 2 beta tester out there (trying to get in touch with him to ask questions, no luck so far).

GIAC - No plans for an E85 tune and kind of down on it for fuel consumption reasons (mentioned possibility of less than 10 miles per gallon), they are big on running blends of E85/gasoline to run higher octane tunes though, I just don’t think that will achieve the cooling I am after.

EPL - E85 tune in development but cited a concern with the way others were approaching this tune (not sure who they meant), no ETA

SMS - E85 tune is out and it sounds like their plan to address low ethanol content fuel is to provide different maps that can run the various fuels (credit infinkc for this idea), but only upon customer request, then I know everyone is down on SMS on here re the JFonz thread, so not too excited about this option at the moment.

Anyone I missed?

#27

I just don’t think people care.

Is there a lot of discussion on the gtr forum about running e85?no, be cause it’s a poor man’s race gas.

Popular with $5,000 cars but not popular with cars that cost $5,000 for an exhaust.

The audis are somewhere in between. The lack of control of e85 content is enough to make you realise that tuning your car with race gas like parameters on the assumption you’re getting top quality e85 is a fool’s errand and is the reason people with nice cars don’t bother. People into cheap shit boxes that are 16 years old and who can’t afford to run aggressive parameters nay other way think it is genius. That or meth. Honda scene, b5 scene.

Gamblers.

The reason nobody here is really replying to you is because most guys here have been around the block and realise it’s not worth it. You’ve been told as much 3 or 4 times already but seem to keep asking.

Maybe you’re waiting for the answer you want to hear. Wrong approach.

Go get jconz e85 tuned and then test and report back. Otherwise go with something from someone reputable that we know works and won’t kill your car.

#28

Points taken, thanks. Though I am still hopeful that APR can pull this off (they at least appreciate the varying ethanol content issue).

#29

I just wanted to clarify my objectives again as I think most here are thinking max power only. The allure of E85 for me is its ability to run cooler than gasoline while providing higher power output than standard 93 octane. I want consistent power throughout a 25 minute lapping session and I want to keep my oil and coolant temps in check.

I’ve been in touch with a racing fuels manufacturer and they indicated that I should expect my engine to run 10-15 degrees cooler running E85 than their 100 or 104 octane fuels. That sounds significant and is reason enough to continue researching E85.

#30

Just curious if you have tried to blend e85 already with 91/93? you will be quite surprised the difference it makes, which is a good compromise to a full out e85 tune at the moment if you already have an OTS tune.

#31

Have you taken in the consideration that you’ll probably need to carry twice as much fuel during that session on E85?

The allure is really IMHo you falling into the “hype”, what platform did you come from before the S4?

#32

I don’t have a tune yet actually but am planning to get one soon (one reason I am researching E85). I’ll look into blending a bit more and see what I find, thanks for the tip.

Does anyone have any experience running a blend for lapping sessions?

#33

I am taking that into account and yes it does sound extremely inconvenient. I would have to take 4 5-gallon jugs with me to the track each day.

My last car was a 997.2 C2S and it was plenty fast for me from the factory. Amazing track car, not so great as a DD.

#34

Jones is pretty into blending, but not sure if he does lapping.

#35

some race fuel wont do as good as e85 until you get past basic upgraded pump gas fuel like 100 or some 104. Real race gas you can see race gas really shine but thats because e85 has a bit more octane then 100 but isnt better formulted then say 109 or 116.

You cant just have anyone make you a e85 tune and get the benifits of e5. Some of the companys listed can barely tune a standard pump gas car let alone a e85 tune. If it was me. I would just hold out for APR you said they mentioned they were in development of a tune. That to be honest that is your best bet. Some things APR isnt good at testing but when it comes to the B8 S4 they really seem to put in the time and test. You have a great car go with a great tuner like APR. Otherwise your just getting a untested un proven tune that someone called an e85 tune.

e85 is like race gas anyone can make you a race gas tune but not all the race gas tunes are going to be equal

#36

Thanks for your thoughts. I’m with you here and plan to hold out for APR’s offering. In the meantime I may try out their 93 octane tune (no switching for B8.5 yet).

#37

Transporting fuel in your car so you can do a track day is frankly retarded. And likely illegal in some places. That law is like a helmet law…it is there to protect someone who is too stupid to protect themselves.

#38

I agree with pretty much everyone here, and I’ll add:

I’d just run pump tune at the track. Run a few points extra octane than your tune if you can for safety.

At my local track, running stage II APR 93 vs APR 100 was worth 0.5 or less on a 1:24 lap for me. Seriously.

Having a predictable and tossable car at the track is much more rewarding than 30-ish hp from race gas. Sorry I haven’t been on here for a while, so I don’t know what you have, but a front BBK, 2.5 to 3 degrees of negative camber and preferably stiffer springs/sways/damping is all that’s required for the most fun.

Edit - a set of extreme perf tires as well - like the RE-11 or RS3. It’ll last you at least 4-5 days or more. I’ve seen so many sets of expensive PSSs chewed up after one of two track days, it’s comical.

#39

This is the most accurate car comment I’ve read on the Internet.

#40

I’ve never felt like 93 file stg 2 power/heat soak were a even a remote concern while pushing through 20-30 min sessions. This is with/without a CPS. I have always been more concerned with tire temps, brakes or engine oil temps…and of course my driving haha. I wouldn’t risk running a sketchy tune just to feel like the engine was running cooler. You could always bring a 5 gallon jug of e85 and blend it in after the first session (no first hand experience with this FWIW). I need about 1 tank of gas per 3-4 20 minute sessions. Also keep in mind you can usually get sunoco 104 at the track, which is unfortunately around $8/gallon.

Many people here have torture tested this car on road courses and no issues with limp mode, oil starvation etc. I would select the best tune for daily drivability and reliability (eg 93 file if no switching is available).