E85 Ethanol Fueled TURBO Motor

[copbait73]

Goran and others, I'm intrigued by the possibility of fueling my project car with 85 ethanol. Now I must admit, I consider E85 "goat piss" and wouldn't recommend it for anything but reading various comments from Gowan have me thinking maybe I should sit back and reconsider this for my tubocharged 3.6 N.A. motor.
All, what is your experience with the fuel system compatibility issues? What Motronic parts need replacement before use or need monitoring as I use this fuel?
If Steve Wong will listen to my suggestion, will the standard components deliver the increased volume required? Fuel pump? injectors? Any experience here?

[BoxxerSix]

Not much information form my end Porsche related directly, but I know that any part of the fuel system that contains rubber components is subject to deterioration from the E85. Things like fuel lines, o-rings, gaskets, etc that are in direct contact with the raw fuel. Once burnt everything is supposed to be fine from there on out.

I'm not sure if Viton(o-rings) are affected by this or not?????

One other thing I've head is that you should put an additional fuel filter inline before the injection system(or CIS if that's the case) as E85 tends to REALLY clean and flush out the entire fuel system the first few tank fulls. After that the filter can be discarded if need be.

Just stuff I've read/heard as I'm thinking of running this stuff in my DD/beater as soon as a pump is locally available.....


i know there are a few guys in the area running E85 in their turbo cars. Some are Evos, some of those little dodge SRT4 neon things, etc, etc. No problems that I've heard of so far.

[RarlyL8]

I read an article not long ago on E85 and older 911s. Boiled down it is the CIS cars that take the hardest hit. The 3.6L engine you are using should have a better chance of conversion. The magic point seems to be around 7% before tuning is needed. I'm sure you already knew that.
Biggest issue I see is fuel volume. The turbos need more on top of the 40% loss in available BTUs.
Goran knows this stuff well. You should e-mail him if he does not see this thread.

[copbait73]

Originally Posted by RarlyL8

I read an article not long ago on E85 and older 911s. Boiled down it is the CIS cars that take the hardest hit. The 3.6L engine you are using should have a better chance of conversion. The magic point seems to be around 7% before tuning is needed. I'm sure you already knew that.
Biggest issue I see is fuel volume. The turbos need more on top of the 40% loss in available BTUs.
Goran knows this stuff well. You should e-mail him if he does not see this thread.

Thanks, yes I hope Goran jumps in here.
BTUs is a consideration as the standard '73 fuel tank is pretty small.

[beepbeep]

I've run my past three cars on E85 with good results. One of them is turbocharged. My S4 is soon to be converted to E85 as well.

Few things to consider:

- You need 40% more fuel flow to acheve same AFR. Thus if you had 200cc injectors before you'll need 280cc to keep same duty cycle on E85.

- Do not try to gain flow by raising fuel pressure. It buggers up spray pattern and kills pumps. Fit bigger injectors.

- MPG will drop roughly 30% (not 40% as eninge will be slightly more efficient)

- E85 has 104 octane rating and burns slightly cooler. It's a poor mans race fuel and is wonderful to work with in turbocharged cars. It's very hard to make it knock. Burns clean, doesn't leave any residues or carbon in the heads. My exhaust pipe is lightly rusty inside (due to Ethanol converting to water).

- E85 burns faster, thus you should use roughly same advance at high revs as on gasoline. It's burn speed is slightly slower at low load, you can advance the ignition somewhat at low revs/low/middle load to gain torque.

- On boost, it likes to run slightly rich. Lambda 0.81-0.83 is nice.

- Cold start enrichment gain needs to be doubled or tripled (YMMV). Trial and error.

- It will flush your fuel tank clear from harts. Fuel filter should be replaced after first two full tanks.

- Rubber will hold fine. I converted two 15 year old cars with original pumps and hoses and neither leaked or developed any kind of problems. Probably due to filter change.

- It smells fine and you can tell people you are enviromentally consious


Many people overhere use E85 on turbocharged project cars. It will give you additional headrom regarding boost/knock or/and allow you to turbocharge N/A engines depending on C/R. I recon 0.7 bar should be possible on 3.6 N/A porker engine. That should give really nice power curve and tractability.

[copbait73]

Goran, thanks.
When you advise .7bar does this assume reasonable intercooling?
Did you overrun your stock pump capacity with the increased fuel flow?
Do you see increased corrosion on any of the metal parts in the intake system, throttle shafts, valving, etc?
Have you also monitored exhaust gas temperature and cylinder head temps?
Do you have comparisons to gasoline?
I think it would be a hoot to have these green guys here in the US subsidizing my 400HP street racer.

[beepbeep]

Originally Posted by copbait73

Goran, thanks.
When you advise .7bar does this assume reasonable intercooling?

Yes. This is wide-a$$ed assumption of fhere you limit might be. Don't take me by the words.

Originally Posted by copbait73

Did you overrun your stock pump capacity with the increased fuel flow?

No. All pumps I have used had enough margins to sustain stock fuel pressure at increased flow. It might be a good idea to check with gauge first few runs though.

Originally Posted by copbait73

Do you see increased corrosion on any of the metal parts in the intake system, throttle shafts, valving, etc?

No. Heads removed from E85 motors had reddish color inside combustion chambers, probably from coloring agent used here in Sweden. US E85 might not be colored? E85 will make pink "gunk" when mixed with frothed crankcase brether oil but it only makes problems with carburated cars. Never had problems on EFI.

Originally Posted by copbait73

Have you also monitored exhaust gas temperature and cylinder head temps?
Do you have comparisons to gasoline?

No, not personally. I only did WBO2 checks to see everything is in order. Other people did and repport slight decrease in EGT. Cylinder head temps should be proportional to EGT/timing.

Originally Posted by copbait73

I think it would be a hoot to have these green guys here in the US subsidizing my 400HP street racer.

Yupp. you are not the only one

http://www.youtube.com/watch?v=cQZGjqCWLGU

http://www.youtube.com/watch?v=_UdwgHvOJIk

[mb911]

Boy this would be great with my setup but to much rework I think for me.. We have a bunch of E85 right down the road though.. Will any injector hold up to the E85?

[beepbeep]

Originally Posted by mb911

We have a bunch of E85 right down the road though.. Will any injector hold up to the E85?

Yeah. No problem. You just need to find 40% bigger ones (or sufficiently low duty cycle to allow 40% more fuel) and it's more or less Plug & Play from there.

[RarlyL8]

Don't forget the ~30% decrease in fuel mileage. I don't think E85 is 30% less expensive than gasoline.

[copbait73]

Originally Posted by RarlyL8

Don't forget the ~30% decrease in fuel mileage. I don't think E85 is 30% less expensive than gasoline.

Very true, but if I consider E85 as cheap racing fuel and insurance it's not a bad trade off. This car will be driven less than 1000 miles per year. I'm thinking the more immediate concern will be it's small gas tank.

[copbait73]

Originally Posted by beepbeep

Many people overhere use E85 on turbocharged project cars. It will give you additional headrom regarding boost/knock or/and allow you to turbocharge N/A engines depending on C/R. I recon 0.7 bar should be possible on 3.6 N/A porker engine. That should give really nice power curve and tractability.

Gowan, I just finished reviewing my texts for a reality check of the boost you suggested and there it was in CRANE(Cams)/Turbocharger Manual:A Complete Guide to Turbocharging Installation -1974 printing.
11.3:1 compression ratio, 10PSI boost - very interesting. I can enjoy the instant throttle response of high static C.R. and still apply more than a touch of boost at the high revs.
I'll need to design a rocketing corncob logo to paste on the fuel filler.

[copbait73]

Ok, for you guys running 7.0:1 C.R. the chart suggests 30psi boost. Who's the first to convert an EFI TURBO to alcohol? Disclaimer: your results may vary.....

[RarlyL8]

You might rethink that rocketing corncob deal. Might attract the wrong crowd if the picture isn't spot on. Ha!

Unless your E85 availability is better where you live than where I live that touring range might be only as far as your local gas station. There are no E85 stations in my area so it's not even an option.

[David]

I've been thinking about this. I keep meaning to install a dashboard knob so I can easily switch fuel maps on my Motec ECU. Then I could switch maps depending on which fuel I'm running.

I wonder if I could find injectors large enough for E85, but small enough to idle with E10.

[mb911]

Originally Posted by beepbeep

Yeah. No problem. You just need to find 40% bigger ones (or sufficiently low duty cycle to allow 40% more fuel) and it's more or less Plug & Play from there.

so basically switch injectors and have fun?

[RarlyL8]

There would likely be a lot of tuning involved. Ethanol has different characteristics than toluene based fuel. The vapor pressure for one is different. For instance the cold start would be buckets of fuel rich when compared to gasoline while steady hot idle would be only ~30% more fuel. Transitions would be different as well.
You might look at the flex fuel vehicles on the road now. My GMC truck supposedly will run on both gasoline or E85. There are no E85 pumps around here so I've never tried it. I'm almost afraid to becase they are so different. I cannot imagine one injector with that broad of a duty cycle range.

[copbait73]

Originally Posted by RarlyL8

Unless your E85 availability is better where you live than where I live that touring range might be only as far as your local gas station. There are no E85 stations in my area so it's not even an option.

Yes, that was my immediate action, to go out and check on availability. I expect there will be pumps but I will need to do advance planning for awhile. Maybe do some web searching also. Since Indiana is a corn growing state, ethanol production is high on the governor's initiatives. We have a new plant going up not 20 miles away.
I still consider it a very poor substitute for my everyday transportation.

[beepbeep]

Originally Posted by mb911

so basically switch injectors and have fun?

Yup. Or you multiply all in your fuel map with 1.4 and if all of them are under 100% you are fine.

[RarlyL8]

So Goran are you saying that Motronic injection will automatically compensate for the massively different A/F ratios? No chip tuning necessary?

What are the compromises of one injector with the capability to run both gasoline and E85?
I can see where my ulta-low output GMC truck could run such an un-optimum system, but a Porsche turbocharged engine? Would you not want to build an exacting fuel system?