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How to run your LS1 on E85
Thread Starter
TECH Fanatic
Joined: Aug 2003
Posts: 1,130
Likes: 1
From: Tranås, Sweden
I dont konow if this has been answered in this thread (21 pages is getting too long to read in full, sorry):
There are some "boxes" on the market that claims that when connected you can run anything from straight E85 to straight gasoline.
As I understand, what these boxes do is to richen the overall fuel delivery and relying on the fuel trims to be able to compensate.
My question is this: On a stock LQ4 engine would it be enough to richen the VE table by say 10% ?? I was thinking it is no need to buy a $450 box if I can do the same with my HP Tuner.
Here in Norway it is not practical to tune for straight E85 since there is only a few gas stations that carry E85 unlike in Sweden where it is all over the place......
There are some "boxes" on the market that claims that when connected you can run anything from straight E85 to straight gasoline.
As I understand, what these boxes do is to richen the overall fuel delivery and relying on the fuel trims to be able to compensate.
My question is this: On a stock LQ4 engine would it be enough to richen the VE table by say 10% ?? I was thinking it is no need to buy a $450 box if I can do the same with my HP Tuner.
Here in Norway it is not practical to tune for straight E85 since there is only a few gas stations that carry E85 unlike in Sweden where it is all over the place......
But if you want to run gas also then add 15% to ve, but remember that the PCM and stock lambda dont work very well over 4000rpm.
ok, so i changed my stoch AFR to 19.7 (max in ls1edit is 20) i know have a 10.9 to 1 AFR commanded. i bumped my WOT vs RPM to 1.402 (havent done any WOT yet). it seems to not be too far away i still have about 15%-20% 93 in it. LTFTS are -13 at the moment
The commanded value is only a reference point for the PCM. The o2 sensors are there to tell the PCM if the AFR is stoich or not. You have extra gas in the tank, you said 15-20%, your Fuel trims are at -13% so they are adding 13% more fuel because the o2 sensor tells them thats how much fuel is needed for the AFR to be stoich.
Your messured AFR is 10.9, if you had 20% gas added to the E-85 you put in, that would make the ethanol/gas blend 35% gas and 65% ethanol.
The stoich value for E-65 would be right around 10.9
Your car is running the way it is supposed to.
Run out the tank you are on until it is nearly empty, then refill it with E-85 and you will be right where you want to be.
You should not set the stoich value to anything but stoich. If you are having fueling issues you need to tune the car.
If after the new tank your AFR is still off, there are lots of ways to fix the fueling, some better than others.
People will change the injector table or the MAF table or tune the VE table or all of the above. If you don't know how to do this, I suggest do alot of reading/learning before you try. It's not hard to make a mess of things, the PCM will make the adjustments for you until then.
When I switched my truck over, all I changed was the stoich value and it runs fine. I haven't checked it with my wide band to confirm it's right but I just passed emissions so why bother. I have my hands full with my car right now.
Your messured AFR is 10.9, if you had 20% gas added to the E-85 you put in, that would make the ethanol/gas blend 35% gas and 65% ethanol.
The stoich value for E-65 would be right around 10.9
Your car is running the way it is supposed to.
Run out the tank you are on until it is nearly empty, then refill it with E-85 and you will be right where you want to be.
You should not set the stoich value to anything but stoich. If you are having fueling issues you need to tune the car.
If after the new tank your AFR is still off, there are lots of ways to fix the fueling, some better than others.
People will change the injector table or the MAF table or tune the VE table or all of the above. If you don't know how to do this, I suggest do alot of reading/learning before you try. It's not hard to make a mess of things, the PCM will make the adjustments for you until then.
When I switched my truck over, all I changed was the stoich value and it runs fine. I haven't checked it with my wide band to confirm it's right but I just passed emissions so why bother. I have my hands full with my car right now.
ya, i wanted to get the stoich set to 9.76. After that i adjust the LTFT's the best i can with the MAF tables...i dont have a wide band so i make sure my PE table is rich and i dont mess with the VE tables.
i dont understand what is so hard to tune,i set my stoich AFR to 9.673 and filled my tank with E85 tuned my idle to part throttle to 4000 in speed density with the LTFT and had it dammed near spot on in thirty minutes. was way easier than with regular gas and has ran great ever since i will not switch back to gas.
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Verdad Gallardo why would you tune it that way?thats wrong you should not have changed your MAF table till your VE table is correct?You have to tune your VE table first you do not need a wideband to tune part throttle only wide openthrottle with a wide band, your making it to hard remember the KISS principle Keep IT Simple Stupid!No insult intended
so after 22 pages of this thread im a little stumped. i just decided to throw about 10 gallons of e85 on top of my 93. just to see what happens. seems to run smoother, but under little or part throttle it seems to have a shudder or a miss. i have stock fuel system for now but to run full e85 i will need a pump. say 255 walbro or such and some bigger injectors. correct? the tuning is where i always spend almost all my time and i have unlimited dyno time so i will strap it down and spend a day reading the thread and playing with my hp tuners. as far as hard parts though what is needed?
i have a tune, it runs excellent on pump gas im just guessing it leaned out with the 10 gal of e85. thats what the miss was about, that didnt answer my question though on what hard parts were needed to run e85 besides a pump and injestors.
TECH Regular
Joined: Jan 2007
Posts: 411
Likes: 1
From: Louisville KY
I've been on E-85 in a GTO for 2.5+ years now. 1.5 FI.
Very simple, basic, FYI. You can use up to a 50/50 mix of gas/E-85 without doing ANYTHING to it. IE, tuning. The ECM will adjust to richen the mixture up to about 20%. Then you will get a CEL after going farther...
E-85 requires about 25-30% more fuel so, Moving from 30 to 40# injectors adds the correct amount with little to no tuning. But why buy injectors and not add some headroom?
I've ran Walbro pumps for over a year with E-85 without trouble.
At 11# of boost 92 octane with 3 gallons of E-85 added to the tank runs great and allows timing >20 degress.
At 15# of boost that mix gives out, more KR than total timing. I saw about 3 degrees total timing and lots of KR.
At 15# of boost on E-85, with 190 degree air intake temp, and 25 degrees of timing I had no KR. It's hard to get that much fuel flow though. 60# injectors and Walbro pump are all maxed out.
All on stock LS2 GTO engine.
Very simple, basic, FYI. You can use up to a 50/50 mix of gas/E-85 without doing ANYTHING to it. IE, tuning. The ECM will adjust to richen the mixture up to about 20%. Then you will get a CEL after going farther...
E-85 requires about 25-30% more fuel so, Moving from 30 to 40# injectors adds the correct amount with little to no tuning. But why buy injectors and not add some headroom?
I've ran Walbro pumps for over a year with E-85 without trouble.
At 11# of boost 92 octane with 3 gallons of E-85 added to the tank runs great and allows timing >20 degress.
At 15# of boost that mix gives out, more KR than total timing. I saw about 3 degrees total timing and lots of KR.
At 15# of boost on E-85, with 190 degree air intake temp, and 25 degrees of timing I had no KR. It's hard to get that much fuel flow though. 60# injectors and Walbro pump are all maxed out.
All on stock LS2 GTO engine.
I've been on E-85 in a GTO for 2.5+ years now. 1.5 FI.
Very simple, basic, FYI. You can use up to a 50/50 mix of gas/E-85 without doing ANYTHING to it. IE, tuning. The ECM will adjust to richen the mixture up to about 20%. Then you will get a CEL after going farther...
E-85 requires about 25-30% more fuel so, Moving from 30 to 40# injectors adds the correct amount with little to no tuning. But why buy injectors and not add some headroom?
I've ran Walbro pumps for over a year with E-85 without trouble.
At 11# of boost 92 octane with 3 gallons of E-85 added to the tank runs great and allows timing >20 degress.
At 15# of boost that mix gives out, more KR than total timing. I saw about 3 degrees total timing and lots of KR.
At 15# of boost on E-85, with 190 degree air intake temp, and 25 degrees of timing I had no KR. It's hard to get that much fuel flow though. 60# injectors and Walbro pump are all maxed out.
All on stock LS2 GTO engine.
Very simple, basic, FYI. You can use up to a 50/50 mix of gas/E-85 without doing ANYTHING to it. IE, tuning. The ECM will adjust to richen the mixture up to about 20%. Then you will get a CEL after going farther...
E-85 requires about 25-30% more fuel so, Moving from 30 to 40# injectors adds the correct amount with little to no tuning. But why buy injectors and not add some headroom?
I've ran Walbro pumps for over a year with E-85 without trouble.
At 11# of boost 92 octane with 3 gallons of E-85 added to the tank runs great and allows timing >20 degress.
At 15# of boost that mix gives out, more KR than total timing. I saw about 3 degrees total timing and lots of KR.
At 15# of boost on E-85, with 190 degree air intake temp, and 25 degrees of timing I had no KR. It's hard to get that much fuel flow though. 60# injectors and Walbro pump are all maxed out.
All on stock LS2 GTO engine.
TECH Regular
Joined: Jan 2007
Posts: 411
Likes: 1
From: Louisville KY
Not yet, I have #'s for 6 psi. 480/560. I want to get enough fuel before I get #'s for 15. I could do 10 but $$$ wasted? I have track times in my sig for 15.
When I was N/A and bone stock I gained 20 hp and 30 tq with E-85. I have dyno charts posted on ls1gto.com
When I was N/A and bone stock I gained 20 hp and 30 tq with E-85. I have dyno charts posted on ls1gto.com
TECH Regular
Joined: Jan 2007
Posts: 411
Likes: 1
From: Louisville KY
I'm not sure what you've got going on there but if you are having big problems Go back to the oem tune.
instead of messing with ve and maf, or stoich, I'd use the injector table first and leave stoich at 14.7.
If you moved from stock 30# injectors to #42 then that makes you %40 richer all by itself. It should be running about %10 rich with E-85 on the oem tune in that case. Close to where you need to be without any tuning AT ALL. Then all you need to do to get LTFT's right would be to lean it out about %10 across the board.
This all assumes you kept the OEM 4 bar fuel pressure.
instead of messing with ve and maf, or stoich, I'd use the injector table first and leave stoich at 14.7.
If you moved from stock 30# injectors to #42 then that makes you %40 richer all by itself. It should be running about %10 rich with E-85 on the oem tune in that case. Close to where you need to be without any tuning AT ALL. Then all you need to do to get LTFT's right would be to lean it out about %10 across the board.
This all assumes you kept the OEM 4 bar fuel pressure.
Last edited by ericwilloughby; Nov 11, 2009 at 05:08 AM.
already did the adjustment and re-did my whole injector table one at a time for the 42# (what a pain in the ****) i have a stock tune to mess with, if i want to star all over again.
Teching In
Joined: Nov 2007
Posts: 4
Likes: 0
From: Santa Clara, CA
Hey E85 folks, a few questions.... I have a few Evo buddies running E85 and they said that:
-TJ
- Any submerged fuel lines do need to be upgraded. In a C5Z only the fuel pump/pickup are submerged, no lines correct?
- The fuel-sock needs upgraded. Did any of ya'll run into that?
- Other open issues?
-TJ