Yes you could change the calibration of the lc-1 to output ethanol lambda, but that just adds more confusion in my mind when tuning and comparing pump gas numbers.


Correct. I believe Lucas English has tuned several e85 cars to close to 13:1 gas lambda. I consider that agressive. Conservative would be anything richer than 10.5:1 gas lambda. My car is currently in the 11.5-11.8 range on e85 and gas lambda.
I think that you'll find your fueling maps only require slight tweaking but your timing maps will require the most tuning to really gain from the increased knock resistance (octane) of e85. You'd be surprised how much timing you can advance without knock on it, much like race gas.

Hard to say. I was hitting 285 or so on 93. e85 saw load over 290. Adding a GM 3 port and upping boost I'm in the 310 load range. Still have more tuning to do, but I would dare say you are going to be pushing 350 after advancing ignition timing.

Correct. If your fuel trims were right on with pump gas, you should only have to make minor corrections to get your e85 trims in line. From there, crank the boost and then start enjoying how much more aggressive you can get with the corn. Hit me up if I can be of any other help or share my maps with you.

 

Another question, did you guys have to re-gap the spark plugs? I've heard you have to run .019" or something crazy on the stock ignition?

 

Nope. Running NGK copper BR8ES gapped at .024 with no break up at all at 29psi.

 

Question to the E85 cracks. (Sorry for the double post, but maybe more people find it here)
This morning I need to crank my car 4 times to start with E85.
Which parameters in ecuflash can be changed to help the starting?

 

I haven't switched to E-85 yet, but I don't think anyone has found the answer to this question yet.

I remember posts asking about cranking ignition tables or routines during cranking, but I don't think anything was found, at least that I remember.

Have you tried logging while cranking to see what voltage, ignition, etc is being used? I'd be curious to see the voltage during cranking. Maybe a lower voltage is present and one of the lower latency values can be increased to just increase the fueling during cranking? Maybe there are completely different fueling/ignition for cranking?

I'm interested in this answer as well, since I plan on switching to E-85 this summer maybe and I want to avoid the hard starting in the winter as much as possible.


Eric

 

What works to help a lean start is to raise the min temp for closed loop 40-45*C and enrichening the fuel map in the 500-1500 rpm / 20-40 load range

 

Thanks a lot. I will try this soon.
Another tip (from a german forum, thanks to gpunkt) was to fake the Water Temp Sensor signal to tell the ECU it is dammed cold out there.
Press a button like a choke in classic cars.

 

Ted I would love to see the first post updated with a bit of a howto and any new info you have on the subject.

be a good resource for us unleaded ppl

what injector size is recommended for stock turbo?

 

So, I made the switch last night! Woo Woo!

And holy crap, you can really tell by the smell when the E85 hits.. Yipes, can't hide that from anyone... Especially with no cat...

OK, here is the process I did, and it was more than successful:

I let the tank get as low as I dared go on the way to the gas station. When I filled it up, the tank took in 13.74 gallons, so there was about 1/4 gallon, plus whatever was in the fuel lines and rail to "get rid of". I filled up and drove to the other side of the gas station, and simply sat in the car with it idling. I flashed the car prior to starting to have the idle with the A/C on at 1500rpm, just to speed up the process. It took probably 5-7 minutes for the car to all the sudden start running lean, and stumble. You could definately tell when the E85 hit the fuel rail, and started to go through the motor.

I let it run, stumbling around for about 2 minutes, then turned the car off and reflashed it for my "general" 30% injector re-scaling number. I went from 1083 scaling for FIC 1050's to 750, and it made the fuel trims sit at 2.846 Low and 5.7877 Mid after about 15 minutes of driving. This morning however, I changed the scaling to 731 to see if I can get it on the slightly negative side, and it's still changing and adjusting itself. Currently as of 5:30 this morning, it sits at 2.6501 Low and 4.415 High.

To those of you guys that haven't made the switch, definately do it. It's very forgiving, and it's really apparent when first driving it and watching knock counts. It was soo easy to do, I wish I would have done it earlier.

Now, a few things that I noticed:

1. If your fuel trims and scalings are right on with 93, you will have very little problems doing the switch.
2. Take your current scaling, using myself as an example, 1083, and reduce by 30% for a good start point. Mine was changed to roughly 750, and made my fuel trims almost exactly as they were with 93.
3. Fill up your tank with as minimal as possible 93 already in it.
4. Sit and let the car idle. I only reset the idle and had the A/C on to make the car consume the 93 in the rail a little faster.
5. Wait for the car to stumble and start running lean. (It's readily apparentwhen it hits the fuel rail/injectors)
6. Turn the car off and reflash for your 30% reduced scaling value. (I also at this time changed my idle values back to where they were before.)
7. Drive around and wait for your fuel trims to level out, and adjust your scaling as required. My latencies, as of 5:30 this morning don't seem to need to be touched at all, due to them being spot on with 93.
8. Start your normal tuning process for part throttle, and WOT.

It really was easy, I don't know why I was so nervous to do it. Now, I wish I would have done it before because I would probably have had better track times a few weeks ago!

Another note, when I started the car for the first "cold start" on E85, she fired up right away. I did change the Min Coolant Temp for Closed Loop to 20, but am going to go higher than that. (20 is only 68 degrees F) I am going to try 35 as that is 95 degrees F, which the car will never be after sitting all night. I also changed my fuel table values, 500-1000rpm 20-40 load from 14.7 to 11.0 to try and aid in cold start-up. The car fired up the first time. (I even have a startup data log of it.)


So a quick summary of all the things I changed to switch to E85 (In terms of ECUFlash)

1. My scaling, went from 1083 to 731 as it sits as of 5:30 this morning.
2. 500-1000rpm's 20-40 load from 14.7 to 11.0 (Don't think this is going to stay this way though)
3. Min Coolant Temp for Closed Loop from 7 to 20. (Going to raise to 35)
4. My exhaust smell. (He he..)

That's literally it. (Keep in mind, this was only to get the car to run and drive with say >20% throttle. You will need to do a full tune on the car to get the fueling correct at WOT, along with your timing tables as well.)

 

I have been running e85 for over 6 months now with a tune based on the 9417008 rom & have been seeing P300 CELs at cruise. Recently I switched to the 9417014 rom & copied my tune over - again I was still seeing P300 CELs at cruise.

Recently I decided to try out some different strategies to tune out the P300 and see if I could tweak a couple of other issues like excessive RPM drop when approaching stops signs.

Originally I had my 1000 cc injectors scaled to 609 cc on e85 with the latencies tweaked to where everything looked good. After alot of experimenting with different injector sizing & latencies, I landed on a tune based on 680 cc injector sizing with custom latencies.

The result is most of my small driveability issues like P300 CELs and excessive RPM drop after throttle lift are completely gone. Even though new tune has the AFRs & LTFT values dialed to match my original tune, most of my minor issues have been resolved. My Creader is now history!

Based on my results I would have to guess that P300 CELs are being caused by fuel delivery settings. It might be interesting to see if a normal P300 car could be cured by rescaling the injector value and tweaking the latencies to match.

My car has seen temps anywhere from 70F (still spring) to -30F over the winter on e85 and I had no starting issues. For me the trick was to tweak the latency at voltages starting at 9v & below. With the right curve on the bottom end cold start is flawless.

Just thought I would share.

 

Nice, that's what I was hoping for. How much did you have to increase your low end latencies by?


Eric

 

I suspect that people are using latencies that are way off at the lower voltages. Hoping to add some clarity on latencies soon.

 

One of the things that I did with my latencies when changing to 1050's was to take the stock latences and graph them out in Excel. What you will see is that the latency values produce a nice gentle curve. When I tuned my 1050 latencies, I made another graphed line on that same graph to represent the new tuned latencies, and got the slope/shape of the line to mimick the stock curve, only at a higher level. It has worked great...

If you take my latencies and the stock latencies, graph them out, you will see exactly what I mean..

FWIW, here are mine:

3.912
2.304
1.512
1.152
0.816
0.6
0.456

Here are the stock values:

3.312
1.68
1.032
0.672
0.432
0.264
0.144


Take a minute, graph them out, and you will see what I mean.

Cold start at lunch today, she fired the first crank too... But, it's also low 70's out here too..

 

My question was more along the lines of adding even more latency to the lower voltages to add much more fuel during cranking (if that actually is how it works).

When I say cold start, I mean below 0 cold starting, during the winter months.

The biggest complaint with E85 is the cold start issues (cold weather start) and I was wondering if simply bumping the lower voltage latencies even more would help that. According to erisohi, that is what he did and it worked great. I'm just curious how much he increased the lower voltage latencies.


Eric

 

It would be interesting to look inside the ECU of a flex fuel vehicle and see how it handles sub freezing cold starts.