Ted B

iTrader: (6)

Another forum member ("dude") and I tackled his TME turbo, mildly modded EVO VIII yesterday.

First, we installed his PTE 880cc/min injectors, and used my FIC 850s (both are the same Delphi part) for the base scaling and latency. He did the driving with me in the passenger seat, on the laptop. We drove on the freeway until I had the Mid LTFT trims within 2%.

We drove until we were well into the fuel reserve. At that point, we added 5 gal of E85 and let the car idle with me doing the logging. As the car began to run rough, I watched the STFT go upward. When the car died, it was at +25%. This is telling us that it was added 25% more fuel to maintain closed loop AFR.

I multiplied the injector scale by 0.75. We started the car, and it fired up and idled smoothly. After driving around, I watched the trims.

When all was said and done, the final scaling was 71% of the original 93-octane value, and I ended up bumping the latency a notch or two to tweak it. We then went on to make WOT pulls for the purpose of tweaking the fueling and ignition maps, but not before we noticed that our cruise EGTs had dropped by 100deg F vs. 92 octane.

Interesting . . .

TeStUdO

iTrader: (6)

Hopefully it's that easy to scale my 1000cc's when I do my E-85 tune.

bnice01

iTrader: (4)

dang +25%, isnt that the max value that evoscan can read?

interesting but thanks for sharing Ted

Ted B

iTrader: (6)

I thought it was 30%, but you may be correct. Irregardless, it turns out that a 29% reduction in the scaling number was right about on target for us. Naturally, this assumes that your present scaling and latency are reasonably accurate.

It is that easy. Just be sure you have enough fuel pump and injector capacity to support this.

If the ECU's max allowable scaling is "1000", that would mean 1400cc/min (according to my results) would be the largest actual injector size that could be configured, so long as E85 is the only fuel the ECU will ever see.

bnice01

iTrader: (4)

great info ted , we need some E-85 in the panhandle

l2r99gst

iTrader: (2)

I have an E-85 station 2 minutes from my house...the only reason I haven't converted yet is because Walbro themselves state that their pumps aren't compatible, even though a lot of people are using them with great success.

Walbro was actually confused by the results that they got in their labs compared to people in the field, so they were/are offering 2 new replacement pumps if you send in your pump that was used with E-85.

It's been a while since I have been to that thread, but here is the link, starting on page 46. If you read from here on, you will see what I am referring to.

http://forums.nasioc.com/forums/show...803341&page=46


Eric

eitan

iTrader: (1)

I've had around 800 gallons of E85 pumped through my Walbro 255 with no known issues to date. I have not pulled the pump and inspected it or any of the lines leading from it, however.

slicedbreadno2

iTrader: (9)

Great info Ted.

Jack_of_Trades

iTrader: (17)

There is two aspects to tuning E85 compared to gasoline.

The first being the stoich mixtures for cruising.
Gasolines stoich ratio is 14.7:1 (1.0 lambda)
E85's stoich ratio is 9.765:1 (1.0 lambda)

Going from 14.7:1 AFR to 9.7765:1 AFR is roughly a 33% increase in fuel so your 29% values are pretty spot on.

If you are using a standard wideband designed for use with gasoline (almost all are), you'll want to see 14.7:1 during closed loop, just the same as gasoline would read. In actuality, you're AFR is 9.765:1 but the wideband reads in lambda and does a mathematical conversion for gasoline, not E85. The stoichiometric lambda reading for both fuels is 1.0 and on your wideband, 14.7 = 1.0 lambda.

Gasoline's "MAX POWER rich" ratio is 12.5:1 (0.8503 lambda)
E85's "MAX POWER rich" ratio is 6.975:1 (0.7143 lambda)

As you can see, the major difference between gasoline and E85 comes into play when you are tuning your open loop AFR's during WOT pulls. On your wideband, 6.975:1 (0.7143 lambda) would read 10.5:1. Running E85 at this AFR is the equivalent of running 12.5:1 with regular gasoline. As you know, our engine design isn't really capable of allowing a 12.5:1 AFR without the onset of knock with pump gas. Most tuners find that running a richer mixture closer to 11.5:1 on gasoline yields good overall results. This is roughly an 8% increase in fuel over the "MAX POWER rich" AFR for gasoline. With e85's higher octane rating, this generally isn't necessary. So your target AFR during WOT would be 10.5:1 AFR on your gasoline wideband gauge.

Since E85's "MAX POWER rich" lambda value is much lower than gasolines, you'll probably have to add more fuel up top during WOT pulls. If you ran 11.0:1 at WOT on gasoline, you'll probably need to add roughly 5% more fuel up top. If you ran a 11.5:1 AFR with gasoline, you'll want to add roughly 9% more fuel up top.

Once you've scaled the injectors for stoich at closed loop cruising, the easiest way to get yourself in the ballpark is to open up your high octane fuel maps for the E85 and highlight all of the cells from 160 load and up. Next, click on FILE, the select "MULTIPLY DATA" and enter .95 (if you ran 11.0:1 on gasoline) or .91 (if you ran 11.5:1 on gasoline). Next, I'd highlight all of the cells from 100 to 160 load. Then I'd click on FILE again and select "Interpolate horizontally". This will smooth the transition from cruising to open loop a little better.

This isn't perfect obviously, but it will get most users a really good starting point.

l2r99gst

iTrader: (2)

Most of the people running E-85 and the threads that I have read are running WOT at 11:1 - 12:1 on a gas calibrated wideband. Lucas has even gone leaner than that, but I believe he tunes in that range.

So, based on what others have tested (since I haven't yet), it doesn't look like you have to run 10.5:1 (gasoline calibrated) for E-85.


Eric

Jack_of_Trades

iTrader: (17)

Definitely don't need to "set it and forget it" at that range. Thats just a SAFE starting point. If I was taking someone's pump gas tune and modding it for E85 without ever doing a WOT pull, I'd start at the 10.5:1 and work my way up. Seeing as the octane is higher, you can certainly go leaner before the onset of knock. You can actually go too lean and still not have any knock, though you will start to lose power output. So while you are leaning it out, be sure to keep an eye on the power curve as well

dude

iTrader: (12)

Ted and I tuned my car at high 11's AFR on a full tank of e85 using the lc-1 set to gasoline (14.7:1). On an 86 degree day, with two people in the car, a full tank of gas and a full weight Evo (no weight reduction at all) we were seeing load ranges above 280 and no more than 2-3 knock counts with a significant timing advance over 93 octane and the IC probably pretty heatsoaked. Running the ac, turning ac off, doing a WOT pull, pulling over, reflashing, and repeating didn't give my stock IC a whole lot of time to do its thing.

We were expecting a much more complicated tuning process, but were pleasantly surprised at how well it ran after just rescaling the injectors.

As far as driveability goes, it feels just as strong as it did before on 93 oct + 100% methanol, if not stronger, and with no worries about the tank running dry or the nozzle clogging. My previous tune was with the Xede with SMART and made 326hp to the wheels at Dyno4mance. Ted and I ripped out the Xede since it was causing TPS and Coolant Sensor errors, so the e-85 tune is just on Ecuflash alone.

Running the 9417008 rom with Tephra mods. Still have the annoying p0300 at 74mph and 26% throttle, hoping that switching over to 9417015 might alleviate that and allow me to finally unplug my darned Creader for once and all.

Regarding the walbro; on 93 octane it made a noticeable whirring sound while priming the fuel system, and now on e85 it is barely audible. So far AFR's and IDC suggest it's keeping up just fine, will report back after some more tanks go through it. I can see where colder climates would have startup issues on e85. It was very warm yesterday, and although the car started everytime with no additional cranking, the rpms would not jump to ~1500 and then settle as they did on 93 oct, instead the car started and immediately went to idle rpm.

All in all I'm pretty excited about it and want to give a big shoutout to Ted B for all his help. Hopefully we can post up after we get his monster Evo tuned on e85 as well...

TalonFiero

iTrader: (18)

I've put over 20,000 miles of e85 through my Walbro in my IX.

I have a 4yr old walbro in my talon and it has 3+yrs worth of e85 and still running fine.

Ted B

iTrader: (6)

Yes, good point. I didn't even consider the difference in those ratios with ethanol vs. gasoline, and since E85 is 85% EtOH, that will make a difference. Ah well, that is actually good news (more power on the way).

When I get back to tweaking dude's car, we'll bump the fuel mixture in the relevant load cells to that indicated AFR (10.5), tweak the ignition map, and we should see greater load before the onset of knock.

bnice01

iTrader: (4)

all I can say is good luck ted, I tried the same thing with me running ALOT of meth. DLL said I made more power but I went thru plug like you wont believe. here the thread wont go too far into detail. my equation was a little off @ first LOL, a little sleepless thinking

https://www.evolutionm.net/forums/sh...=316480&page=2