E-85,ifr ?

[Lextech]

This may be a stupid question, but I'm going to ask it anyway. If fuel pressure and injector size are unaltered when switching to E-85, Does the IFR table need to be altered? I am unsure if E-85 flows differently across the injector as opposed to gasoline. I may try to run E-85 in the next few days.

Jeff

[joecar]

Jeff,

I don't think E85 flows differently...

but its stoichiometric AFR is differernt (9:1...?), so B3618 will have to be changed.

I am also told it may run leaner so you have to bump up VE/MAF tables slightly (or IFR table down).

But, I have no experience with E85.

Joe

[Lextech]

Thanks Joe,

On a side note.
I have been on the Innovate Website quite a bit lately. The administrator/engineer Klaus says NOT to reconfigure the W/B for E-85. He says to leave it setup for gasoline. The W/B measures in Lambda and converts the number to the fuel type that you have programmed into the controller. So---On a Gasoline N/A engine max power is at about .88Lambda or 12.9 AFR (14.7gas AFR times .88Lambda = 12.9 AFR) On an E-85 N/A engine max power is at about .73Lambda or 10.7 AFR-----If your W/B is set up for Gas and reading E-85. On a boosted engine max power is at about 9.8 AFR -----If your W/B is set up for Gas and reading E-85.
DISCLAIMER---To the BEST of my knowledge this info is correct---If it isn't someone please point it out. I haven't tuned anything for E-85 yet!!!!

Jeff

[kbracing96]

Jeff, I ran my truck on E-85 for a while just to try it out. If your tune is spot on for gas, then you can do what I did.

All I did was ran it down to where there was only a couple gallons of gas in my truck and filled with E-85 and set B3618 to 10:1. Watched my STFT and they where pulling fuel about 8-10% so I bumped it back up to 10.8:1. STFT looked good there. Did that for a couple tanks till I got to where I was pretty much all E85 in the tank. and ended up right at about 10:1.

Problem with doing what the Innovate guy was saying is you can't AutoVE with the WB displaying in gas conversion and the PCM commanding for E85 AFR, as there about 4.7 points off.

So what I did was created a calculated PID to convert both my wide band and my BEN factor to the correct AFR for E85. This let me AutoVE for E85 and tune it right in.

I was shooting for about 7.2 AFR with E85 in boost, but that stuff never knocks. I had it lean out to 8.3 Cuz I was out of fuel pump (Walbro 255 intank with 60lbs/hr injectors) and 22* of timing and Never saw any KR. You have to be really care full if you want to push it with E85, It ended up being the death (well not completely) of my 4.8.

I was playing with it to see how far I could go, (stock, cam only 4.8 btw) so I cranked up the boost to 14psi, had 23.5* of timing in and really fat, 6.3 AFR. Went out for a tuning session and turns out that combination is too much cylinder pressure for stock head bolts, lol. It lifted the heads and pushed a bunch of coolant out the over flow. Turned the boost back down to my normal 7 PSI for the street, and it was ok, bumped it to my high street boost of 10psi and it held that, but 11psi and water would come out, so it was weak. I ended up just dropping it back down to 7 psi and driving the truck for 2 months while I built the forged LS1 that's in it now. E85, it some good stuff thought.

You will use more of it though I went from 14-16 Mpg down to and average 10.6 for the 4 tanks I put though my truck all though I never got a chance to tune it for lean cruise. This stuff never seems to knock, so I think you could run it pretty lean and get some of the mileage back. This was all just an experiment for me. I calculated with the current price of premium and E85, it was costing me 5 cents more a mile to use E85 them premium. But it is like cheep race gas if you would rather look at it that way.

[Lextech]

Thanks KB,

The last "Test and Tune" for the season is on Tuesday (It is Sat. now) With these 3 Hurricanes/Tropical Storms bringing rain to the whole country, I don't see much chance of test and tune. So, That gives me some more time to think about this E-85 stuff.

Jeff

[vzsv8]

Have a look at the link below for some theoretical background on E85.

http://www.ls1gto.com/forums/showthread.php?t=264727

It suggests around 9.5 to 1 for stoich for E85, so at max power the mixture would clearly need to be somewhat richer. It would also make sense to build in some more static compression to take advantage of the increased octane to partially compensate for the increased fuel consumption.
Cheers, Seve

[GMPX]

Did any of the Aussies on here see the 60 minutes report on E85 fuel? It was interesting to see Brazil where majority of cars are running E85 the air in the cities was very clean.

The problem as I see it in the US is they are using corn crops to make E85, not sugar cane like Brazil and Australia, maybe that explains why the price between regular unleaded and E85 is very small and people are complaining that crops are being used for fuel not food.

Cheers,
Ross