Topic: e85 tune from trifecta

[Gentleman Jack]

What happens if you can't get e85 and have to fill up with standard fuel?

[2.0 tspeed]

What happens if you can't get e85 and have to fill up with standard fuel?

i cant lolz i have a few e85 stations around me and a 5 gallon jug sitting in my vw and at the house just in case.
if i had the cables i could just switch it right back to 93 so i will b buying the cables soon

[Gentleman Jack]

So you would damage the engine running standard 91 fuel?  Only one E station in San Diego... Too risky if reg 91 fuel will damage the car.

[Kelu]

You must change the tune if you fill with normal gas.

[GT!]

Can't Vince program two tunes (select-a-tune)?  Program one for E85 and the other for premium gas.

-GT

[tazz]

So you would damage the engine running standard 91 fuel?  Only one E station in San Diego... Too risky if reg 91 fuel will damage the car.

Depending on what your actually running as far as full E85 or a lower concentration like E47-E25 and how much and where they increased timing it could be dangerous if pushed into boost.
I think most have raised the timing in the mid to high load ranges so if you just kept it out of boost you could limp it home and be fine running on 91 since in the low load range no timing changes are made.
If your actually running full E85 you might not be able to keep it running since it will be adding alot of fuel and the ECU may not be able to pull enough fuel out for the 91.  

[tazz]

A stock car will probably tolerate a E15-E20 and actually probably higher concentration before it won't run since the FT's will be too far off for the ECU to correct and have trouble idling.

[tazz]

Slowsol
Did you get a layer tune or strictly a HPT tuned?

[2.0 tspeed]

It's just strictly trifecta playing with hpt later due to some financial issues

[Gentleman Jack]

Bummer.  Was looking forward to plYing with this....

[tazz]

Me too.
I wish I knew more so I could attempt to play a bit.  From what Ive gathered you have to be consistant on the mix and then increase the injector constant by the amount the LTFT are thrown off so the LTFT's are close to zero without altering the stock MAF frequency table and fine tune with the MAF correction table.  You also probably need to raise FP a bit but not to the 2900psi max maybe 2400-2600psi? then start working on the timing tables to get the power up.  If you leave the stock timing tables inplace you will actually see a decrease in power due to the lower potential energy of Ethanol vs gas and not taking the advantage of raising the timing. Also will need to play with the cam tables a bit if you want to get some mileage back and better cold startup's.  

This is just what " I can gather from reading"  and I may not be right just the way way I interperate the info I read.

You can however dump in about 1-2 gals of E85 to a tankful and get the benefit of raised octane and rid yourself of any occasional knock that pulls timing without hurting performance with your timing tables.

[kennysabarese]

the knock sensors in the LNF are effective. I think if you drove 91 on an E85 tune, it would probably not blow up as long as you didn't fill it and floor it.  But who's going to test it to find out

[Sol Asylum]

the knock sensors in the LNF are effective. I think if you drove 91 on an E85 tune, it would probably not blow up as long as you didn't fill it and floor it.  But who's going to test it to find out

GJ would be more then happy to be the first to try it.



PS can he borrow your car?

[2.0 tspeed]

hoping on dyno today ill post up numbers as soon as i go

[tazz]

Running about a E40 mix today seems fine and logs are good.
Just played with the Injector constant to bring the LTFT's to almost 0 and actually worked very well.  Multiplied the stock injector constant by 1.155 and is almost spot on and drifts from 0-.8 on the LTFT's.   Need to work a bit on the STFT'S but they were never higher than 4 through a WOT run. Logged Commanded FP as well as FP at the rail and it was good stayed almost dead on with commanded just a ramping effect as it builds and decends. Did not raise timimg yet but didnt get any KR maybe this week I will play with it.
Looks like adjusting the Injector constant could also be used to correct any deviation to the LTFT's so that a person doesnt have to mess with the stock MAF table and just adjust the MAF correction.

[Kelu]

Cool, nice piece of info right here tazz

Good Luck, I can't follow this path cause there are no pumps with E85 around here. In Romania, close to my city  is one of the biggest plants of Bio Ethanol from Europe, but we can't buy it, everything goes to export in industrial quantities. FFS