Autronic Air Fuel Meter B models E85 Fuel

[JanIvar]

Hello

Can someone give me more information aboute tune cars with E85 fuel.

And I also want to calibrate Autronic B model Analyser correctly for
this fuel, anyone experience with this.?

And someone tell me that E85 can use leaner fuel.?
We always tune every cars with exsaust temp.

[roberto arano]

see here: http://www.mrm-racing.se/forum/showthread.php?t=66

lamda 1 is still lambda 1, the 02 sensor knows no difference. If you want to read in AFR either do the math to convert using the ratio of petrol stoich=x/E85 stoich=x or setup your wideband the correct stoich for E85.

Keep in mind the stoich for e85 ,by mass ratio, is about 50% fuel to air higher than petrol. 9.8 vs 14.7

Many people don't change the stoich in the meter and just work off the AFR petrol scale even when reading E85. The target lambdas are roughly the same (actual best must be determined by dyno tuning of course).SO your unconverted AFR targets are roughly the same on that scale. See the chart below .

The basic thought though is that in load ranges when you are not knock limited the e85 will make more power at a richer lamda than petrol, but does not have to be enrichened as much when in knock limited loads, because the effective octane is so much higher.

SOme say timing requirement is less if not knock limited (e85 is faster burning), but demands less retard when knock limited (octane rating again).

my egt's are lower with e85 maybe 100 degrees F, however i have not done any scientific back to back comparisons.

It's a better fuel in many ways,the major disadvantage is you need to use more volume of it!


also look at this chart from the web:

http://en.wikipedia.org/wiki/E85_in_standard_engines

[JanIvar]

Good information.

Do you have any info, how to calibrate/setup for read AFR E85, in the Autronic B models Analyser. we use NTK wideband.
Im a little unsure.. then I can just select E85 in setup on analyser when we tune this cars.

Some one have tell me that in winter then E85 only is E77? correct?

[MRMRacing]

Here in Sweden E85 can be as low as E70 in wintertime. You may have to consider using a GM sensor to read the fuel/E85 contents and adjust the Sm4. With this you can mix fuel and E85 in the tank.

[JanIvar]

MRM, If I understand correct. if i tune car om E75 now, and then customer fill up the
car with E85 then the car will go with leaner fuel. Octane same on E75??

[MRMRacing]

Yes thats the problem with aftermarket ECU tuned for a certain fuel quantity, the cars like Volvo, SAAB and more do adaptive learning so they are not affected.
You have to tune on E85 and then it will run little richer on E75.

Else you have to use a sensor that outputs the fuel quantity to the ECU for correcting this for changes in the fuel mix.

[JanIvar]

Have any info how to calibrate/setup for read AFR E85, in the Autronic B models Analyser. we use NTK wideband.
Im a little unsure.. then I can just select E85 in setup on analyser when we tune this cars.

[roberto arano]

on the sm2;

i use a combination of the overall fuel trim pot on the ecu case and the closed loop correction to get consistent mixtures with varying ethanol blends.

the autronic is nice beacause even if you only have clc operating at say idle and cruise conditions, it will maintain the CLC corection % across even the open loop sites. Basically it is sampling the % in the tank via the o2 sensor correction ....

So you had E85 in the tank and it was applying 10% CLC, and you filled up with E70 as soon as the 02 sensor is warmed it will need to apply 8.2%.

The main reason it works with the autronic even with a narrowband is because even when the ECU is operating open loop it still applies the last known CLC correction, it does not default to zero. It holds CLC and applies it until it is on a closed loop site again,and start actively trimming.

someone correct me if i am wrong for other ecu's chips.