E85 gas on a stock 1994 Civic DX????

[JustRob]

I dont know < The rex runs like a beast on the shit! thanks stolle!@

Remember that stolle also tuned your car to run on E85.

[White91Hatch]

Remember that stolle also tuned your car to run on E85.

Yeah tru dat! corn oil smells weird!

[zrs6v4]

I understand that you'd have to tune a turbo d15b that has been chipped of course, but on a stock ecu d15 it should make up for itself....... when you drive a flexfuel suburban do you have to tune it to run 87 to e85? id say no, so I dont understand the tuning part of it unless your car is already running a map piggyback. So if you are running a turbo crx that is chipped then you'll have to of course re-tune it to compensate for needing more fuel when running e85. the only thing that would make sense on a stock car would be to need larger injectors, different style rubber lines, or a larger fuel pump (which I dont see). I also understand the long term affects on this stuff possibly, but not proven to me yet other than word of mouth. In my eyes if something on my fuel system fails as far as not being able to handle the big percentage of added fuel or ethanol than it was already weak to begin with. The only thing that would make sense so far is that maybe my injectors arent big enough, which again is questionable. I dont think a tank can hurt it unless there is already a weak area in my system. I have ran nitrous on a stock integra GSR and a stock 01 prelude and neither needed bigger anything or replacement anything. I ran 100 octane unleaded and the stock pump, injectors, and untuned ecu all worked fine. Not saying that it couldnt have been tuned better or more efficient with timing changes, but My point is through 20 bottles I never had a single issue. Id be more scared changing stuff around than running it on a stock car.. Does this make any sense as to where I am confused?

[JustRob]

I understand that you'd have to tune a turbo d15b that has been chipped of course, but on a stock ecu d15 it should make up for itself....... when you drive a flexfuel suburban do you have to tune it to run 87 to e85? id say no, so I dont understand the tuning part of it unless your car is already running a map piggyback. So if you are running a turbo crx that is chipped then you'll have to of course re-tune it to compensate for needing more fuel when running e85. the only thing that would make sense on a stock car would be to need larger injectors, different style rubber lines, or a larger fuel pump (which I dont see). I also understand the long term affects on this stuff possibly, but not proven to me yet other than word of mouth. In my eyes if something on my fuel system fails as far as not being able to handle the big percentage of added fuel or ethanol than it was already weak to begin with. The only thing that would make sense so far is that maybe my injectors arent big enough, which again is questionable. I dont think a tank can hurt it unless there is already a weak area in my system. I have ran nitrous on a stock integra GSR and a stock 01 prelude and neither needed bigger anything or replacement anything. I ran 100 octane unleaded and the stock pump, injectors, and untuned ecu all worked fine. Not saying that it couldnt have been tuned better or more efficient with timing changes, but My point is through 20 bottles I never had a single issue. Id be more scared changing stuff around than running it on a stock car.. Does this make any sense as to where I am confused?

You can't compare a 15 year old OBD-I Honda ECU to a new GM OBD-II ECU. Like stolle said in the link posted by JesSi, it takes 30% more fuel to achive a stoich A/F ratio when using E85. Running E85 was something that the OEM Honda ECU was never meant to do. And remember, you can't just throw in larger injectors with a stock ECU and expect it to know that is not running 240's anymore.

[JesSi]

If he wants to run his car lean as hell, let him.

[LowePerf]

when you drive a flexfuel suburban do you have to tune it to run 87 to e85? id say no, so I dont understand the tuning part of it unless your car is already running a map piggyback.

Your closer than you think. Actually it's the exact same fuel map! The ECM uses Lambda for fuel calculation so it does not care wether it has gasoline or E85. Lambda=1 is stoich for all fuels. But the ECM has to know the stoich ratio of the fuel. Flex Fuel vehicles have a sensor in the tank to measure the alcohol content and this is input into the stoich value of the fuel in the ECM to set Lambda=1 at whatever percentage of E85 you have at that time.

I have ran nitrous on a stock integra GSR and a stock 01 prelude and neither needed bigger anything or replacement anything. I ran 100 octane unleaded and the stock pump, injectors, and untuned ecu all worked fine. Not saying that it couldnt have been tuned better or more efficient with timing changes, but My point is through 20 bottles I never had a single issue. Id be more scared changing stuff around than running it on a stock car..

Not really any comparison here as the nitrous sytem is jetted to maintain an A/F ratio that is safe.

Does this make any sense as to where I am confused?

It gets very confusing, take for example my 2003 Ford Expedition. With a change to 1 parameter in the whole tune(stoich fuel ratio) changed from 14.64 to 9.85. I can go fill up with E85 and it will run without issues. Consider though that timing must be advance to compensate for the slower burn rate, so now that I'm already burning 33% more fuel to maintain stoich and burning it inefficiently with less than MBT timing and you can see it's a losing battle without retuning it.
Right now, E85 it about 10% cheaper than gas over here, so burning 33% more is not even cost efficient. I don't need the octane value in this so I'll stick with gas for now!
-John

[zrs6v4]

You can't compare a 15 year old OBD-I Honda ECU to a new GM OBD-II ECU. Like stolle said in the link posted by JesSi, it takes 30% more fuel to achive a stoich A/F ratio when using E85. Running E85 was something that the OEM Honda ECU was never meant to do. And remember, you can't just throw in larger injectors with a stock ECU and expect it to know that is not running 240's anymore.

Yea your right about the ecu comparisons, I understand it take much more fuel to achieve stoich, and I understand that you cant run bigger injectors on the stock ecu without at least some sort of piggyback even though what I said was badly worded. what I meant was I can understand having to run larger injectors and getting a tune due to the 240's being to small. I didnt think it would be that big of a fuel change and I do not know much about how ecu's work I just figured it would know to dump a little more fuel in on its own which doesnt really make a whole lot of sense i guess. My nitrous statement doesnt make a whole lot of sense either, hah, seeing as you'd run the same amount of fuel. thanks for clearing this up

[mlr198769er]

maybe its just my opinion but its a waste of time. Think about it why dont you go put 110 in your car and run that everyday. Theres no point and you'll lose power because more ignition timing is needed when running higher octane fuels which include e85. If your going to run it run higher compression to get all the power that is in the fuel. When i was building my motor i calculated what the fuel i would have to buy which was 93 octane. I took the price of e85 and times that by 1.3 which will add the extra 30% fuel needed. I would actually lose money. And i have a 14:1 sohc. Stock motor would just not be worth it. Here we'll do some figures.

93 octane is 2.49 a gallon here in columbia. 87 is 2.19. and e-85 is 2.09

e-85+30%=1 gallon of gas
2.09x1.30=2.717 per gallon equivalent

granted for the octane that it has it's worth the money but octane dont mean crap unless your pushing the fuel to the edge of detonation (ex. in a race car)