How to run your LS1 on E85

[n0dih]

Cool, what do you have the 3.8 in?

[TrailBlazer SS AWD]

Great Write Up. Does Anyone Have An E85 Tune I For A 2008 TrailBlazer SS AWD With A LS2?? I'd Like To Know What I'd Have To Change.

[KFZ)^]

Hey fellow E85'ers!

I am of Irish descent, so is it really any surprise that I like running my car on alcohol? And my 2001 Z06 is loving it too. The car has been running on 100% E85 for a few months now, and the Ford 42-lb "Green Top" injectors are working well.

The only real issue I would like to work out with the tune is cold starting. I live in San Diego and it is summer now, so it isn't really "cold," but when starting the engine when ECT = ambient temp (e.g. in the morning), it takes longer to start. If the engine is warm (only been sitting for a few hours, etc), it starts right up. I tried experimenting with the Cranking FA and Prime Pulse tables but my efforts do not seem to have helped.

tahoe, thanks for sharing the text files with the tables that you modified. I am going to take a look at them, and modify my tables accordingly. I will return to post my results.

... looking forward to some N2O + E85

[Throttle]

switched yesterday to E85 this should be a sticky with the availability of E85 becoming more and more accesible at our favorites money pits "The Gas station"

[ttbestas]

Guys who are runing e85, how do you modify fuel transient tables or you just leave them stock? thanks

[ttbestas]

Guys who are runing e85, how do you modify fuel transient tables or you just leave them stock? thanks

ttttttttttt

[jakebdb56]

Just a quick question. I have some e85 injectors and plan on doing the swap this week sometime. I downloaded a 06 1500 e85 flex fuel tune and the only difference between that and my stock one is the injector settings. The stoich table is the same, (sloped for alcohol content percentage, shows 9.76 for 85%) and I'm assuming that the PCM can somehow magically pick up the alcohol content in the fuel. I've heard of this before, but never had any experience with it at all.

Anyways, just wondering. It's about 2.00/gallon for e85 here while 2.75/gallon for 93. It's about an equal tradeoff going to e85 as far as mileage/money is conerned but the horsepower increase and cleaning effect of e85 I think is going to be a big payoff.

[Ls1c5vette]

Bump. I have a LM2 wideband installed, can I still read the air/fuel ratio in "AFR" instead of Lambda? Or do I need to change it to Lambda instead of AFR?

I found this on another forum. It's helped me get full understanding to finish my e85 tune.
"Understanding Air/Fuel ratios
This article assumes you already understand the concept of the air/fuel ratio (AFR), but if not, familiarize yourself by visiting this Wikipedia link. You may have already read that E85 has a different stoichometric air fuel ratio than gasoline's 14.7. The stoich AFR for E85 (at 85% Ethanol) is 9.76. The stoich value represents an ideal perfect burn of the fuel usually used at part throttle conditions. Full throttle conditions require a richer mixture than stoich to prevent the dreaded detonation, or pinging.

However most AFR gauges you can purchase to display a numerical value of the AFR, are showing you values for gasoline. This is where it can get tricky, and it's important to understand how this ratio works on both gasoline and ethanol-based fuel.

All AFR's regardless of fuel type work off of a common number called Lambda. A value of 1.0 in Lambda represents the stoich for any fuel. Gasoline is Lambda 1.0 at stoich. E85 is Lambda 1.0 at stoich.

If you already have a standard gasoline AFR meter hooked to a wideband O2 sensor, you can still use the displayed gasoline AFRs in determining your engine's true AFR. For example, if your gasoline meter is showing 14.7, then we know this is Lamda of 1.0. The equivelent on the E85 side is around 9.7. Therefore you can conclude that the 14.7 you see on the gauge is a true AFR of 9.7. This allows you to effectively use existing gasoline AFR components or software to tune an E85 Mustang without buying special equipment. Simply use the same target AFRs on your gasoline gauge that you normally targeted for gasolline. "

Ok so I can do some WOT runs on E85 and if my LM2 says I am at 12.8 AFR then I am good to go w/ E85 (tune it like I am tuning for normal gas)? Or do I need to get it to 8.5 on the LM2 for AFR @ WOT? I am kinda confused. I am going to change my stoich to 9.66 before I start tuning.

[waynehartwig]

Great write up! In for the tech

[NoGamesLS1]

I've been running e85 for a couple months. Been very happy so far. I am running 42# green tops, but will be going to 52's or 60's here pretty soon. I went to the dyno recently, for those who may be interested in seeing what can be done with e85, here is the thread. http://www.ls1tech.com/forums/dynamo...acing-cam.html

[Ls1c5vette]

Just did the switch to E85 today, drained the tank at the fuel rail with the fuel pump on till it sputtered, then put 5 gals in, changed the Stoich to 9.799 and added 2 deg of timing across the board. Fired right up, runs smoother (no more low rpm bucking at 1400-1600 rpm), smells great, runs 10* cooler and def has more power up top and on the low end, I am right at stoich in CL and about 8.9-9.1 in open loop. Its a little rich at 7.1-7.5 AFR @ WOT but I suspect that its due to 1-1.5 gals of 100% gas left in the tank that mixed with the 5 gals of E85, so I am going to drive it till its almost empty tonight and fill it back up with E85, it should lean out a tad to where it needs to be. I have 54lb inj's and they are at 95% duty cycle.

BTW I am not using Lambda cause my LM2 has a function in the settings (on the computer with the LM2 connected) to change the reading for stoich E85 (9.799) so it reads in AFR just fine. I still cant get my AFR error to read right tho in HP Tuners.

[NoGamesLS1]

Just did the switch to E85 today, drained the tank at the fuel rail with the fuel pump on till it sputtered, then put 5 gals in, changed the Stoich to 9.799 and added 2 deg of timing across the board. Fired right up, runs smoother (no more low rpm bucking at 1400-1600 rpm), smells great, runs 10* cooler and def has more power up top and on the low end, I am right at stoich in CL and about 8.9-9.1 in open loop. Its a little rich at 7.1-7.5 AFR @ WOT but I suspect that its due to 1-1.5 gals of 100% gas left in the tank that mixed with the 5 gals of E85, so I am going to drive it till its almost empty tonight and fill it back up with E85, it should lean out a tad to where it needs to be. I have 54lb inj's and they are at 95% duty cycle.

BTW I am not using Lambda cause my LM2 has a function in the settings (on the computer with the LM2 connected) to change the reading for stoich E85 (9.799) so it reads in AFR just fine. I still cant get my AFR error to read right tho in HP Tuners.

My WB will read from .68 lambda to 1.36 lamba. So to config in the defined configs I put the lowest number (rich) as my offset in the box just to the left of the "+" sign. Then I took the difference between the leanest lambda reading, 1.36, and the richest, .68, which for me was .68. Now I took 5 (for the 0-5 volt reference) and divided it by the difference, .68, and came up with 7.353. This goes in the lower box. Yours may differ if your WB will read a wider range from lambda.

[Mr. 2008 SS]

Thinking about E-85 so the stoich to 9.799 and added 2 deg of timing across the board. Is just one part of the set up to run E-85 yes

Thanks,
Mr. 2008 SS

[n0dih]

You don't add timing across the board with E85. Depending on load, some areas you PULL timing from the map, some you add more.

Pull the L59 Ethanol Timing Adder table and look at it, shows a very good way to do a static E85 timing map.

Thinking about E-85 so the stoich to 9.799 and added 2 deg of timing across the board. Is just one part of the set up to run E-85 yes

Thanks,
Mr. 2008 SS

[Mr. 2008 SS]

Family, keep the E-85 love coming

Thanks,
Mr. 2008 SS

[Mr. 2008 SS]

E-85 BABY...
If any ones wants information PM me

Mr. 2008 SS

[murphinator]

mr 2008 ss if your on e85 and in the northeast you must be in NY or MA ???

I keep waiting for it to get closer and have only done blending to date since I have to drive 2 states to get it....

[RSTinOKC]

E85 stations are pretty sparse locally, but I do have one about 5 miles from where I work...this is very tempting. Theoretically my existing pe curve should correlate as long as I change stoich to 9.66? Say if I'm at 12.6 @ 14.681 with gas I would be at 11.25 @ 9.66 with e85...just thinking out loud here.

edit: Scratch that last part...is the same NA pe fueling principle applied to E85, i.e. stoich at idle/cruise progressively fattening to redline?

[cfaluck13]

E85 stations are pretty sparse locally, but I do have one about 5 miles from where I work...this is very tempting. Theoretically my existing pe curve should correlate as long as I change stoich to 9.66? Say if I'm at 12.6 @ 14.681 with gas I would be at 11.25 @ 9.66 with e85...just thinking out loud here.

edit: Scratch that last part...is the same NA pe fueling principle applied to E85, i.e. stoich at idle/cruise progressively fattening to redline?

Should your wot afr be lower than 9.66 if that is stoich?

[Iam Broke]

If your PE is 1.2 ish, then yes. I moved over from the Turbo LNF world so for me it's easier to think in Lambda (Bosch ECU) but 9.66/1.2 = 8.05 AFR for 1.2 PE

.83 PE Lambda is the same regardless of fuel. Stoich is always 1.0 Lambda.