E85Forum.com

WRX Harvey · Joined: 14 Aug 2006 Posts: 6

Hello, this is my first post here. I have been playing for a few weeks now. I am a professional ECU reprogrammer specializing in aftermarket upgrades. Hotrod is a freind who I have watched using ethanol for years in his subaru.

My car is a 2.5 liter turbocharged subaru. It is moderately modified and I recently retuned my vehicle to run on e-85 with no additional gasoline. I was impressed with the behavior of the car after the fuel switch. I only changed the fuel map and tuned the car to run stochiometric under cruise and about .8 lambda under boost.

The concrete evidence is less than scientific since I had no baselines with my current setup. I was able to monitor knock correction using some proprietary logging equipment. Using the powermeter and third gear pull, the maximum power was the same, but I did not make any changes to the timing of the car. That will be my next experiment. Knock correction with ethanol seemed to max out quickly and stay higher than on gasoline. The car is definitely peppier on hot days.

I haven't been to the drag strip in over a year in this car. Previously I had run a 13.0 with a smaller mitsubishi 18g turbo and smaller topmount ic versus my new front mounted intercooler and 20g turbo. I only did 2 runs and it was 91 degrees farenheit out at Bandimere speedway in Denver at 5280 feet of altitude. On my second run I ran a 12.44 e.t. at 112.7 mph. I am very happy about the results and beleive the ethanol allowed me to run well in the intense heat.

I also helped tune a freind's rx7 twin turbo on a 33/67 blend in his car. He ran a 13.1 versus a previous best of 13.4.

I have a shop car that is currently at 385hp on 104 octane gasoline and I plan to retune it on e85 as well so as to have some good comparisons. I will now turn this into the e85 test mule. I have had to go back to gasoline because local ethanol is very scarce but hope for a few local stations who are trying to start carrying it.
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12.44 @112.7 on E-85 at 5280 feet Alt.

WR^2X · Joined: 14 Aug 2006 Posts: 29 Location: Geneva, IL

Lots of NASIOC people showing up here! I'm also running a 2.5 with a 20G. I have 850cc injectors, an upgraded TMIC, full 3" exhaust, an EWG, and a UTEC. I've been working on my E85 map for a few weeks now, and the car absolutely loves it. This is the third map stored in my UTEC. I've got an E10 map, an E35 map that runs alright between E20 and E50, and the E85 map. It's basically a flex-fuel vehicle now! Laughing

I don't have any power or run numbers for the car with E85, but on E35 it made 350 WHP and 325 WTQ (damn exhaust leaks) on a dynojet. More than the tuner expected a similarly-modded car to do with E10 93, so I was pleased.

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

I'm also going to be retuning my Subaru for full on e85. I'm hoping to use the stock injectors by reducing boost levels and running on wastegate pressure. As it is now, with 30% ethanol, I'm looking at over 97% Injector Duty Cycle. Sad

I'll post more as I get more familiar with the tuning software. Its a bit different from the TecIII software. Lots more control. Very Happy

WRX Harvey can I assume you are running a 06 WRX on stock injectors? I already know WR^2X's setup. Smile

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

http://www.cobbforums.com/forums/showthread.php?t=31091
You want the second link.(edit)

Link to zip file which holds a .xls file which has target AFR for E85 for Subaru, courtesy of Cobb Tuning.

Something which might help WR^2X, but is something we should discuss here.

WR^2X · Joined: 14 Aug 2006 Posts: 29 Location: Geneva, IL

So do those ratios match up across columns? Meaning, where it says 8.44:1 is Summer E85 max power lean, does that show as 12.70:1 on a gasoline-calibrated wideband? It looks like that's the way it works, but I need some more caffeine. But I thought max power lean was 11.5:1?

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

That's what I wanted to discuss.
It looks like Cobb did calculations based on ideal mass measurements.

The chart is read straight across, but the max power values are different.
Look for the red and blue highlighted values in each column. Blue is max power rich and red is max power lean for that fuel column.

So max power rich would be 0.71 Lambda or 10:1 on E10 or 6.97:1 on E85.. Scary huh?

It looks like the values are the ideal values, and not the real world tuning values based on dyno tuning. What do you think?

WRX Harvey · Joined: 14 Aug 2006 Posts: 6

I am running self-modified injectors which tested at 830ccs at 42 psi. The rest of my setup is a hybrid 2.0/2.5 engine with fmic, 20g.

I ditched the air/fuel ratio in favor of lambda measurements and have also found that using anything below .75 seems to be too rich. I have not confirmed this on the dyno yet. Am I wrong or does the lambda proposed does not take the 15 percent of gas into account? I am running right at .8 lambda with the best of results.
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12.44 @112.7 on E-85 at 5280 feet Alt.

WR^2X · Joined: 14 Aug 2006 Posts: 29 Location: Geneva, IL

The lambda values in the spreadsheet should be with 15% gas, assuming you're looking at the E85 column. So you're getting good results with 11.8:1 (.8 lambda) on a gasoline-calibrated WBO2? You've tested that ratio on a dyno and it seems to be the best?

WRX Harvey · Joined: 14 Aug 2006 Posts: 6

I have not yet dyno tuned. Those results were just preliminary street tuning data, but the timeslip indicates good stuff. I will be dyno tuning the shop car next weekend on e-85
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12.44 @112.7 on E-85 at 5280 feet Alt.

WRX Harvey · Joined: 14 Aug 2006 Posts: 6

Hello all. I have some good info now.

I went back to the dragstrip a week later. I was there to see if I had gained, lost, or retained the same power with 91 octane gasoline.

Once again I only did one pass, but it was as perfect as the ethanol pass.

I should also note that trap speed is a very good indicator of horsepower and relatively independent of the quality of the pass.

But needless to say because the pass was excellent.

I ran a 12.6 at 107. Temps were cooler. The car weighed the exact same.

I also heard audible ping during the run on the gasoline. On gasoline the car was running .75 lambda and on E-85 it was running .79 lambda. That was the only difference. Amazing that the car would knock even though it was relatively richer.

This indicates a large loss in power versus ethanol.

I can't wait till we have a station closer than 30 miles from my house for this fuel.
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12.44 @112.7 on E-85 at 5280 feet Alt.

WRX Harvey · Joined: 14 Aug 2006 Posts: 6

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

Here is an interesting note from RiftsWRX while tuning WR^X2's car for E30.

WR^2X · Joined: 14 Aug 2006 Posts: 29 Location: Geneva, IL

Jorge's right, I looked back at my dyno plots. I thought he was running ~11.5:1 at redline, but it was actually ~12.2:1 at redline on E30. So I think I will stick with the ~13:1 at redline, running a little more rich at peak torque.

I've recently thrown a CEL though... Need to get my fuel trims nailed down, which means I need to find some way of actually reading the fuel trims. Laughing

WR^2X · Joined: 14 Aug 2006 Posts: 29 Location: Geneva, IL

Just to let everyone know, I've got my fuel trims fixed. Mileage has improved! I got 15.6 MPG for the last tank, which is the best I've ever recorded.

Revision · Joined: 14 Sep 2005 Posts: 194 Location: Carol Stream, IL

I have E85 in the WRX now and it is running fine.

Project Bender has achieved alcohol addiction!! Laughing

I'm running 8psi of boost(wastegate pressure) on stock 440cc injectors and I'm seeing about 90% Injector Duty Cycle running about 11.5:1 AFR ( on regular fuel scale). I think this is still too rich and am trying to compensate.

Mods are STi uppipe, TurboXS stealthback and Street Tuner software.

Oil analysis is next on the menu.