How Does E85 Perform?

[cardoc]

I removed defective CATs and installed straight pipes. This car is tuned to run E85. It runs too rich on gasoline, so E85 is the primary fuel. The video is pretty much self explainatory.

CATs will go back in, I just did this as an experiment and to gather data.
The bad CATs had to come out anyway. The car was running crappy.

Video: https://www.youtube.com/watch?v=kymiztuB5gI


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[cardoc]

E85 is out, Shell 93 octane in. I was really expecting higher numbers. I guess the engine is running more efficient with gasoline than I thought.

Video: https://www.youtube.com/watch?v=3bCHxaw8L0I


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[Crossgolf]

Hey, what exactly did you do to make it E85 compatible? Or what kind of tune was that?
(I can't watch the video right now due to a slow performing connection)

[1 Lucky Texan]

can you run the same injectors and pump for both?

[cardoc]

More air needs more fuel. I have 410 cc injectors to supply the fuel. I am going to upsize to 650 cc to get even more. When the ECM was remapped for the supercharger, the injector latency was changed in order to get the proper fuel shot for the added air charge, along with the timing and knock retard. The last three logs I ran was on E85 and the latency was changed after each to gain the perfect mix, what I have now.

I also have a larger volume fuel pump. The OE fuel pump will supply the necessary flow needed for E85 everyday driving. I just wanted to be sure it would be capable to provide flow for "racing" where the engines runs from 4-7k rpm.

An NA or forced induction engine can be remapped to perform better and gain in fuel economy. To run E85, the latency is increased to provide a longer period of open since the combustion process needs a higher volume of alcohol to get the same burn as gasoline. Generally, 25% more volume is needed. Given the injectors can operate safely up to 85%, I would think that a NA engine can be reprogrammed to run E85 safely, unless you keep the engine rpm on the high side, then you would need to up the injector size. But, when the fuel map is changed to run E85, when gasoline is put in it will run rich. The car doesn't distinguish between the two fuels. It doesn't have an alcohol monitor or capability to switch its map. That would be up to the operator. Switching programming takes less than 3 minutes. If you do the remap, save the original ROM or an updated one on the laptop. Run the E85 program for E85. Switch to the OE or modified for gasoline.

I can run gasoline in the car with the map I run for E85 and keep the mix at stoichiometric for gas. It just doesn't run as well for power output and I have to watch the AF gauges to make sure I don't go rich by changing my foot position on the accelerator. It's just a matter of throttle control.

For math calculation, 14.7:1 is for gas, 9:1 is prime for alcohol.

[cardoc]

And the second video is running gasoline on the map used to run E85.

[Crossgolf]

Originally Posted by cardoc

...

I also have a larger volume fuel pump. The OE fuel pump will supply the necessary flow needed for E85 everyday driving. I just wanted to be sure it would be capable to provide flow for "racing" where the engines runs from 4-7k rpm.

An NA or forced induction engine can be remapped to perform better and gain in fuel economy. To run E85, the latency is increased to provide a longer period of open since the combustion process needs a higher volume of alcohol to get the same burn as gasoline. Generally, 25% more volume is needed. Given the injectors can operate safely up to 85%, I would think that a NA engine can be reprogrammed to run E85 safely, unless you keep the engine rpm on the high side, then you would need to up the injector size. But, when the fuel map is changed to run E85, when gasoline is put in it will run rich. The car doesn't distinguish between the two fuels. It doesn't have an alcohol monitor or capability to switch its map. That would be up to the operator. Switching programming takes less than 3 minutes. If you do the remap, save the original ROM or an updated one on the laptop. Run the E85 program for E85. Switch to the OE or modified for gasoline.

...

For math calculation, 14.7:1 is for gas, 9:1 is prime for alcohol.

Sorry, but what do you mean by "NA engine"?

E85 is about 40% cheaper where I live. But I don't plan to do any big changes to the engine if I can avoid it. Besides switching the map, what changes would you do to a stock H6 to run E85? You said that you think that the injectors can stay but what about the fuel lines and the injection system. Wouldn't the alcohol harm the rubber when it is in there four too long? Did you make any bad experiences with that?

[SE95]

Originally Posted by Crossgolf

Sorry, but what do you mean by "NA engine"?

NA means Normally or Naturally Aspirated (depending on who is talking). Meaning there is no form of forced induction (via a supercharger or turbo charger). Cardoc's car is supercharged, so it has forced induction rather than being NA.

[cardoc]

So far, at 8k miles running E85, I have only had one issue with fuel and I don't think it was due to the alcohol. A fuel hose split at my Aeromotive pressure regulator. I think I got a bad roll of hose.

All the seals were new when I installed the upsized injectors. I had them out a couple thousand miles ago and so far, no swelling. The hoses at the tank are doing great as well as the other OE hoses I left in place. Its all in the name of science, so don't say it. Besides, I have extra fuel hose in the car with tools. I would expect a failure in the hoses first since they get the most flow and volume with fuel going to the engine and then back to the tank.

Crossgolf, a good remote tuner can remap your ECM. Ed at XTreme Racing Tuning did mine and knows what needs to be done to make it work without a MAF sensor and without using the MAP sensor wholly. Tell him CarDoc sent you. He's good people and only maps Subaru. He drives one.

[cardoc]

And, he's in Barbados and does it via e-mail.