zerMATT951

So... Several people have their M-Tune installed for a while now, surely someone has done a comparison dyno run. Right? I'd love to see some numbers...

I am curious to know what 93 octane at 18 PSI versus E85 at 21 PSI looks like on the same car, same dyno, and similar conditions. Who's got graphs they can post?

At a minimum, I'm curious to know what fuel mileage does with the change. Typically E85 is 15-20% less fuel efficient compared to gas, I'm curious to know of that holds true in these cars with M-Tune.

refresh951

No data here, switched to E85 and have no intention of returning to pump fuel.

zerMATT951

Are you running a WB? I'm curious to know what my AFR will do when I change. I've read the discussions and it sounds like I shouldn't see much of a difference and that 12.5 is still the maximum safe target.

Rogue_Ant

The first tank full of E85 will likely be a little rich - this is due to the leftover gas in the tank mixing.

And yes, your target AFR will be similar to what you are seeing now.

zerMATT951

I just wish my gas gauge wad accurate or that my odometer worked... I'll be shooting in the dark regarding fuel level when I switch over.

bw993

I have been using my M-tune with E85 on the track for the last month. AFR at Willow Springs at 140mph was 11.5 in 5th gear @ max. boost 20 PSI. Performance was awesome. I will be upgrade my turbo from K26/8 to K27/8 before next event.

ChrisJ951

you can always put the E85 in a gas can, drain the pump fuel and refill with E85.

ChrisJ951

My question is, can these 23+ year old engines really handle E85? The stuff can't even be transported in the same pipes as normal gas due to corrosion. I wonder what that does to the internals of an engine?

Personally I found 106 octane pretty close to me. Its a lot more expensive, but since its not my daily driver the cost won't be that bad. I won't use E85 in my car.

refresh951

This has been discussed a great deal here in many threads. It is not as corrosive as some suggest. Many have ran it for years without issue. I think it is a great option for these cars because it goes a long way in preventing knock.

blown 944

Lolololololololololololololol......

Hmmm how many years has it been now? Let me think, over fifteen years running ethanol and over seven years running e85 in my DD and stored 944's. Got to love the enthusiasm...

Crackership

Or just put some in a jerry-can and drive around until the car dies

I'm definitely interested in seeing what others have to say about this... I'm not sure what E85's effect on aluminum (or alu-sil) is. I know that I've heard that E85 is corrosive from a good number of people, but these are usually the same people that have told me that placing a car battery on concrete will drain it... There's a lot of "old wife's tales" when it comes to cars... and a lot that aren't so old. I, personally, have a hard time believing that, what is essentially moonshine, is more corrosive than gasoline. Maybe it is.. I don't know, I'm not a chemist. But I do know that E10 has been around since the 80's and, presumably everyone here's car has run through many many tanks of it...

m73m95

I've been on e85 for ~a year now. I know I'm just an NA car, but the principle of it is the same.

With the tune I have now, I get between 18 and 20MPG in the city. On the best highway run I made, I got ~22mpg. It wasn't a full tank of highway, but 75% of it was. FWIW, I could get 29 on the highway, with the AC on, on gasoline.

I think I can do better too. I'm not the most proficient tuner in the world, so I think as I get more practice, my mpg's will go up a little more.

blown 944

I'm having flashbacks..I should go look look on pelican and see how long ago it was I was having these discussions.

I truly thought everyone was over this...... I need to just avoid this...but I can't. I'm not sure how many years or miles it will take for this thinking to go away. One thing I know for certain is that my engines have lived a hell of a lot longer due to E85. Very certain!!!

blown 944

As for power, I have wittnessed a pretty well tuned car run in the turbos efficiency range at 18 psi up here and went 104ish. I have ran 115-118 at 22-23 psi. So for _REAL HP_ not dyno id say around 310-320hp on pump and 400 hp on e85. At sea level the hp would be higher. But this is a direct comparison for cars set up to run these two boost levels efficiently.

onspeed

Was getting ~14-15mpg, 50/50 city highway with e85. But I was on boost... a lot.