Can ls1's run on e85. Are there any type of modifications that need to be done so they can run on this stuff. I heard that they can?

 

It should run fine at part throttle. Would not be getting full power at WOT. Some people argue you won't get as much MPG but I would think you could jack the spark timing up more to compensate.

 

so you think with a handheld tuner you can bump up the wot timing and she should run pretty good? what about adding more fuel at wot

 

no.... you won't be able to run E85 w/a handheld... plus as mentioned... I wouldn't go running WOT w/out tuning for it... E85 stoich is like 9.8:1 instead of 14.7:1 like gasoline...

Plus E85 is only 70-80% as much energy as gasoline... so unless the E85 you have access to use 30% cheaper than gasoline, you're wasting your money even more so

E85 = higher octane, less energy ... and you need to run more of it (on a modified car unless you have large injectors don't even think about it...)

But basically unless you have a full tuner, it's not something you will want to try

edit: ALso the reason that E85 provides less fuel economy is that as mentioned... there's less energy in it... since stoich is 9.8 or so to 1 , it takes more E85 to create the equivalent energy as gasoline ...

There should really be a law against how gas stations advertise E85 ... just the other day I saw Premium for 3.20/gallon and E85 for 2.70/gallon ... but that's only 15% off ... so in the long run you spend MORE money on gas at that price... now if it were closer to 2.20/gallon then it'd be about the break even point

Now if you go WOT, the PCM is calibrated (this is open loop... uses internal tables) so that it will try to get say 11.5:1 AFR ... so it'll use pre-defined pulse widths... but now you actually need to run much richer than that to be safe ... the PCM can't correct for this at WOT ... it'll ping, and timing will be retarded

Also... even at WOT I believe on a stock tune, the fuel trims will max (the o2 sensors will work because they measure stoich, not AFR ... but in order to achive stoich they're going to be very close to the +25% limit ... if they still aren't enough to correct, then you'll get a Lean SES light....

There are some people here who have successfully converted to using E85 (sorry I can't recall the name... DRUN or something? the guy from sweden) ... I'm not sure of the long term effects since ethanol is more corrosive than gasoline ... but short term he's successfully tuned his car to run it... but he has a full tuning sweet so he can log and make changes... also he did it in increments... not gasoline to straight E85... he went from gasoline to a little E85... all the way to all E85


And a final thing... if you're close to maxing your current injectors keep in mind that you'll want 20-30% larger injectors to run E85... yet be the same as far as maxing them (hence why the E85 flex fuel vehicles from GM come w/larger injectors)

 

I have tuned my car to run on E85 mainly because it´s so much cheaper here.. Gas costs 12.50 kronor/liter and E85 costs 7.50...

My "experiments" showed that you can run 40% E85 without setting off an SES.. But any more and you´l have to tune you VE-table. I have made BIG changes to my VE, OLFA and increased fuel at PE. I use #50 injectors but i think that #40 would have been enough.

 

Woohoo!! I got it right

 

Other things i´ve had to changes are my idle airflow and i´m currently experimenting with my cranking VE(is it possible to logg it?) because it doesn´t start right away sometimes..

It might be the cranking fuel tables that needs to be changed?

 

i mix with 25% it runs great!! have done this since last spring.

 

You might try the method we outlined in this thread.
https://ls1tech.com/forums/pcm-diagnostics-tuning/487560-cranking-ve.html

Pretty cool that you have successfully made the conversion though! Are you still using the stock oxygen sensors with it?

 

Isn't Alcohol a corrosive which would require special fuel lines/tank ect?

 

Most of our cars have plastic/fiberglass fuel tanks and steel or plastic fuel lines. No problems.

E85 cars often have stainless steel lines for 100% life with E85, but only in select places.

I run E85 100% most of the time. Unless I can't get to the station (which is 30 miles away).

It isn't too hard to modify, but takes some time and tuning with the datalogger.

Ideally, change fuel injectors to 50% larger than where you are now with gas. As stoich on E85 is 9.75:1, and gas is 14.6, 50% is very close to dead on. Now, you WILL now run rich with gas, and ok with E85. You need to change the injector constant to follow your fuel keeping BLM's close to 128. Else open loop in startup will be either too lean or too rich, depending on which way you go. Boost up timing 4 degrees across the board and move the Ignition timing limit up, stock LT1 is 46 degrees, I keep mine at 55 degrees.

If you do NOT change injectors, avoid WOT runs, as you WILL exceed 100% duty cycle on the injectors. I have seen as high as 114% on mine. Yeah, I know, that is a nono. I don't see "issues" with it at the moment, but I don't do it long either.

I am running LS6 injectors on my LT1 (at 3 bar, so stock size injectors for me) and need larger (anyone got any 40-50 lb/hr injectors for sale?? No Lucas please)

No handheld programmer will likely help you. You need something healthier.

 

Conversion factors:

1 Swedish Krona (SEK) = 0.13596 US Dollar (USD)
1 US gallon = 3.78 Litres
6.17 and 3.85 USD respectively.

 

No, E85 needs much more than steel fuel lines and a plastic gas tank. It will damage all rubber seals that it may come into contact with. The seals need to be converted to viton.

 

Think hard on WHERE rubber exists in our cars.

FPR and injector o-rings. That is it. So far I cannot find anywhere else. I have looked. Not in the tank, not in the lines, not in the rails, not in the injectors, only those 2 places. Possibly in the fuel line connections. That is all.

AND, yes, it is corrosive, it is NOT ACID. It does not eat stuff overnight, it takes many YEARS to even cause the slightest amount of degredation.

I have been running this stuff for a short while, a friend of mine has run it in a school test car for 4 YEARS with absolutely NO ill effects, save 1, and it did nothing to slow the car down or cause issues.

Ethanol is CONDUCTIVE, gasoline is not. It caused some carbon tracking on the fuel pump contacts.

I highly suspect the seals are already viton rubber.

When and IF my FPR fails, I will then swap to a new one rated for alcohol. Maybe not. If I can run it for 4-5 years, why bother? I highly suspect GM has already used rubber than can withstand any effects of ethanol in the early 90's if not late 80's. I cannot prove it, but if I can figure out a way to do accelerated alcohol studies on 90's o-rings, I will. I have a 180K mile set of 8 that have I can subject to "further testing".

I will continue to run E85 as long as cost wise it is worth it. And at this time, I can go 60-100 miles further on E85 for every $60 I spend on fuel Sure, I put more fuel in the tank, but I get more fuel for my $. I have only lost around 10-15% mpg tops. It isn't hurting much at all. And you get a free 3-5% more HP to boot. Why the heck not run it?

 

The only problem i have right now is after a cold start it almost dies when i press the throttle fast... But when it has entered closed loop everything is fine. I have tried the olfa tables from the E85 Tahoe.

Any ideas?

 

Low rpm VE settings, maybe you need more fuel in open loop off idle?
What about throttle follower? You could put more air in there to ramp the tranistion to throttle from idle.
Also is you running airflow good? Maybe at lower ECT it needs a little more?
I guess you might also have too much fuel there. A wideband should help.

 

Go back to stock VE tables, don't mess with them. Then change only the injector constant to the formula I have here: https://ls1tech.com/forums/pcm-diagnostics-tuning/497434-hpp-10-ethanol.html

And your open loop problems will be gone. I had the same issues. Your PCM is trying to fuel for gas, not E85 when in open loop. Messing with the VE tables will mess up the open loop calibrations. FWIK the VE tables are not used at all in closed loop, just open, at least on my LT1.

Once in closed loop your BLM's are probably soaring. Once I got that down, I was running sweet on E85. I just pumped up some timing in the spark tables and that was about it to run E85 with only 10-15% loss in economy and awesome drivability. Even in pure open loop operation I was able to run just fine. VE tables are GM stock.

 

Thats one way to do it... But i have changed my Stoich from 14.7 to 9.77 and that would do almost the same thing.

 

there was a thread on some ford power site where svt sponsored a 95 turbo build up and it made 100rwhp more on e85 vs 93 octane gasoline...i think they said e85 was 115octane

 

I tried that, it doesn't work on the OBD1 LT1 PCM well at all. The transition from open loop to closed loop would cause a large bog until the PCM realized that it isn't going to make fuel for an E85 9.8:1 AFR vs a 14.7:1 AFR gas engine.

2 ways to do it, but I feel that the Injector Constant way did solve a lot more problems than the other way, which is how I went about it first.

Try both ways, see how it goes. Your PCM might be a lot faster than mine, as mine is a 12 years old design.