So if you have a car tuned off of E85 and you put in E70 will it be a big enough difference to require an E70 tune?

If you have E70 and want to make E85 can you just mix in the additional 15% pump gas to balance the two? Or is the process of the blend much more complex than that?

Making the switch sometime within the next couple of months but im unsure of what the fuel I will be getting at the time will be. Id also like to set up a map for both but i wont have both on hand at time of tune so wondering if i can just mix my own E85 if i wait till the winter blend comes out. I read somewhere that you can do this but not too sure of the reliability of the source.

 

What EMS are you running?

 

the afr differences are not that much. proper closed loop will easily compensate. Starting should be close enough, with E70 starting easier anyhow.

If you have E70, you need to add 100% ethanol (E98 essentially) to make E85.

Or you cut E98 with pump gas to make E85.

 

Ok that makes sense on the mixing for the tune. Thanks Str8dum1

Ill be running either the haltech platinum or pro.

Would you guys suggest DW1000's or RC1200's?

I am at 78% duty cycle of my DW600's. If i need the extra 40% more at WOT then the 1000s will be exactly at 78% also. But if i want to go for more power after that then Ill need bigger injectors to stay under the 80% safety measure. Correct?

 

Haltech has flex fuel now too!

 

arent you still on your stock block? 1200s are good to ~800whp on e85 if you have enough fuel pump.

 

The platinum pro has the flex fuel sensor built in?

I am on stock block. Which is a part of the reason for going E85. I wouldnt have to worry about detonation and it would keep my cylinder temps much lower. Plus that stuff is very plentiful here.

But ok. Ill stick with the 1000's.

 

only the stand alone haltech has the flex fuel if you buy the additional sensor.

I tuned mine to e70 on the dyno so I could optimize timing. E70 will have the LEAST octane out of all the ethanol blends so tuned to that with timing I will always be safe. I also tuned the a/f to 11.0. E70 runs richer than e85 so in the summer when I'm on e85 it runs a little more lean, usually 11.8ish. So No matter which blend I'm on I know i have safe timing and the a/f will be between 11-12.

You can do it the other way as well. Tune to e85 up near 12 a/f then when you run e70 it will be low 11's. Either way your closed loop vac map will automatically compensate with the o2 corrections.

 

I thought you need to dump mad fuel on any ethanol. I've heard u need somewhere in the 8:1 fr on wot with it.

 

Stoich on e85 is roughly 9.8:1 which is 1.0 lambda. When you look at display it is calculated based on lambda and only displays what you want. So if you have it set to display 14.7 as stoich (petroleum fuel) then it will read a lambda of 1.0 as 14.7 on the display. No matter what fuel you use if you want stoich (lambda at 1.0) it will output 14.7 on the gauge. It does not care what the actual a/f is only what the lambda is. You could change your display to tell you anything you want at 1.0 lambda and it will be fine.

All the gauge shows is a referenced number based off of lambda. So running .8 lambda for boost is where you want which displays in the mid 11:1 range for pumpgas and if you have 9.8:1 as stoich then it would display 7.8 on the gauge.

Make life easy, leave the display set to pump gas so it's easier to read.

 

here in chicago last winter, nobody switched to e70... well, according to the people at the gas stations i asked. i noticed no difference in the way my 370z was running so i assume they were correct.

i also noticed absolutely no issues at all with cold starting or anything, so i hope they do the same thing this year.

 

I've never had cold start issues with e85 (not e70) even down to 20* outside with 1000cc injectors. I think proper starting tune is the key. Since haltech has so many starting injection options it helps.