E85 questions
 

Question for fuel map tuners: The D4 engine under the hood of these incorporate a direct injection fueling system capable of:

240cc DI flow (est)
2.4ms pulse width

Is there a capable tuner able to play with the fuel map to use E-85 with the stock fueling system? It would be conservative to assume we would see an increase, potentially dramatic increase with more aggressive tuning. Is this a safe assumption and possible with the system, or does the added port injection flow rate screw up the potential, why or why not?

To run E85 you need to increase the fuel flow by at least 60% to maintain the same power level. There is room in the stock system for more power, but not that much.

Team Crawford

Whilst I have the greatest respect for some of your company's engineering skills, that figure of 60% is almost double what is actually required.

^This. While the actual fuel amount varies a bit with each engine and how aggressive/conservative it's tuned, it only needs 39% more fuel for E85.

Just do the math. Ethanol has 67% of the energy of Gasoline. E85 is 85% Ethanol and 15% Gasoline. 1 / (.85 x .67 + .15) = 1.389854065 which means 39% more fuel. Winter blend takes less since it's 70% Ethanol and 30% Gasoline

My guess is Crawford is thinking of pure Methanol. A very common mistake.

http://horsepowercalculators.net/e85...e85-calculator

They are saying 48%

That's because they're talking about air:fuel ratio which is measured by Mass and fuel flow is measured in Volume. Ethanol and Gasoline have slightly different mass due to a different composition. The distinctive trait in alcohols is the presence of oxygen. Ethanol is 1/3 oxygen which makes it heavier per gallon than Gasoline.

http://en.wikipedia.org/wiki/Stoichi..._of_combustion

I had to look this is for an easy explanation.

Please forgive me if that website is some kind of trusted source, but I'm very surprised that a company like Crawford would reference some random url rather than pour some fuel into a car and test for themselves. That's what I've done many, many times with this fuel and can tell you from first hand experience that the figure of 48% is less wrong than "at least 60%", but still wrong.

So, where did you get 60% from?

And why don't you simply use math and logical reasoning to show what the figures actually are. Not only is your statement misleading for those viewers who may be less than educated about the matter, it's just plain wrong.

Coming from a personal business owner, be careful with what you write. Especially if it isn't first hand information.

To the OP, I don't know the answers to your questions ... but as soon as I can get my hands on a car I will be attempting to find out.

How about we start with the easier question of how much fuel flow the stock injectors use and then we can extrapolate the maximum fuel we can run stock.

I have always thought it was about 30-40% and not 60%.

If we were just dealing direct injectors or just dealing with port injectors, I agree that it would be easy.

Has anyone been able to log IDC of both sets of injectors through a pull to redline? That could tell quite a lot.

When you throw significant amounts of alcohol into the mix you really want as much going through the direct injectors as possible. Best to find out how much fuel you can send through the DI first.

With E85 in the fuel tank it doesn't matter. Plus you can't swap out the Direct injectors, that I'm aware of. Port injectors are much easier to swap out and much cheaper as well.