Your thoughts on E85

[Holden202T]

For those that don't know E85 is 85% ethanol blended with petrol.....

SOOO .... i've been doing a bit of reading and trying to work out if its a worthwhile option for a pure race car or if its just worth going the extra step to methanol.

what i do know is:

petrol 14.7:1 (octane 98)
E85 9:1 (octane 100-105)
methanol 6.4:1 (octane 114)

so when you look at it this way, E85 is not that big a jump in octane rating however its added advantage is its available at the pump whereas methanol as far as im aware requires a log book and you have to go to certain places to get it etc ....

on top of that i know that methanol is not very nice to engines wear wise, im not really sure how E85 compares in this department though.

so if anyone can tell me anymore about this fuel, anyone with first hand epxerience or whatever i'd love to hear about it ....

i'm contemplating using it but i want to know what im getting into before i do it and also if i go one way or the other its going to have a huge bearing on how i setup my engine compression ratio wise etc...

[Apples]

Methanol requires 2 times the amount compared to petrol.
E85 requires about 30 % increase in fuel required approx.

E85 can buy from pump most places.
Methanol can buy from race shops a CSR / chemical company's : note there are two types of methanol one is medical and the other is race fuel with oil added.
you can use medical but requires oil to be added like castrol R .

for a idea on fuel usage a 410 800hp sprintcar uses 2.5 lts a 400 meter lap at full noise.

Have see E85 test done and found nearly 90 % methanol in the fuel.

[Holden202T]

that last bit is interesting .... i've heard people dubbing it street legal methanol ....

[Jayme]

dumb question....
that info in the first post. does that mean stioch ratio for E85 is 9:1? would that not render an o2 sensor useless unless you use a wideband and configure it to output 9:1 simulated narrowband?

if I was building an engine id probably run it on E85, if what im reading about it is correct, if you use higher compression and correct tune, it uses less volume than petrol anyway, and being cheaper at the pump - sounds like a win. only downside being, once you raise the comrpesison you can ONLY run on E85, unless you use a petrol safe compresison but then you wont get as good efficiency on E85. note: these are my specualtions based on wikipedia - subject to incorrectness

[Holden202T]

yeah thats right, i'm not sure how you would go about it with a normal o2 .... i know my wide band is programable to suit the different types of fuel ....

i'd love to see an AFR table from a car thats made to run this stuff ...

most of the info i have is from wikipedia also, its a good starting point

i'm not too worried about fuel consumption more just getting the most out of the car that i can so i figured i'll up the compression of this motor and probably do some valve work more just to suit the application it will be used in rather than street .....

i've heard 12:1-13:1 compression ratios are doable for e85 and about 14:1 for methanol ... if thats the case i'd probably try and aim for about 12.5:1 just to be on the safe side and see how it goes...

also the fuel system in my car is setup to run methanol (figured i may aswell do it from day 1) so i should be right whatever fuel i use .... the other thing that was slightly pointing me towards e85 was that i figured theres more chance the holley with some bigger jets will work fine with it whereas on methanol it might be pushing its limits ....

[Apples]

some reading for you

http://www.hotrod.com/techarticles/hrdp ... index.html

If I can find it, one of my other mag has write up on E85 as well

http://www.raceone85.com/

[Holden202T]

i like this part of the first article ....

And while drivers can switch back and forth from gasoline to E85 at will with the flex-fuel vehicles currently offered by the automakers, that is some fairly advanced technology beyond the reach of most backyard tuners. Once you've recalibrated your fuel system for ethanol, you're committed to ethanol until you change the calibration back again.

if my injectors can flow enough fuel and my fuel system is E85 suitable then i can run e85 and normal pump fuel in my old school torana with a delco hahahaha .... out of reach of some backyard tuners, but not all

all you need is a simple switch to change memory locations in a certain realtime board

[Jayme]

dont even need a realtime board to run dual bins, just a 27sf512, a 10k resistor and a switch as detailed in the circuit elsewhere on this site.

[VL400]

dumb question....
that info in the first post. does that mean stioch ratio for E85 is 9:1? would that not render an o2 sensor useless unless you use a wideband and configure it to output 9:1 simulated narrowband?

A narrowband oxy sensor reads stoich (Lamba of 1), the AFR readiing of 14.7:1 is just a calculation so can still run closed loop on E85. You need to configure a wideband to read the correct AFR if you tune using that, tuning to lambda is better if you start working with different fuels - 0.85 lambda is 0.85 lambda regardless of what fuel you run.

[Holden202T]

maybe so but i know how to interpret AFR so i will be using that and re-configuring my sensor