Thread: Another E85 question

OK guys I have a question about possibly switching to E85. I know the basics that with upgraded injectors (42.5#) I should be able to run e85 with a stock tune. My question is would it be possible to run e85 most of the time but possibly run 93 if I cant find an e85 station around me. Basically there are a few stations close to where I live but when I go out of town with my wife to see my in laws (which is maybe as much as twice a month) I dont think there are any e85 stations near there. Just for reference I have an 04 comp g, 180*, SD headers, overkill tune (still have original pcm which I could run with the e85) two stage colder plugs, and 3.5 mps. Thanks in advance

Originally Posted by sseilmnop

Run e85 all the time if you switch. Don't switch if your not changing pulley size, your not gaining anything.

Youll gain some power just running on e85 alone.

Running 93 on 42# injectors is rough. It will technically work but I wouldn't suggest doing it for extended periods. If you plan on running 93 in it try to keep the e content as high as you can for as long as you can. Your car will happily flex fuel itself between e30 and e90 but that range may be different depending on how your car specifically likes to run.

I run 2 pcms you could do sort of the same thing. I have one pcm tuned for e85 and 60#ers and one is tuned for 60#ers and pump gas.

options here.

1 run 42#ers with a smaller pulley (3.4 should be easily doable maybe smaller)and your stock pcm and maybe shorter belt if its needed.

2 run stock injectors and go back to your current setup.

3 have overkill tune changed so 42# injectors work with pump gas. Then you could put 42s in and leave them in.

If I understand your post correctly you have a 42# injector tune as well? If so you can mix in up to e40 on that tune most likely.

I think i'll do what chain stretcher does and just have overkill retune my one pcm to run e85 and keep my one for pump gas in case of emergencies. I would like to drop to maybe a 3.3 pulley from my 3.5 and e85 seems the best way to do it. I was just worried about messing something up if I had to put like a quarter tank of 93 in to get me to an e85 station. Our family is in rural nc and there are not many nearby when we visit. I think I could plan my fill ups just right and be OK, but I just wanted to cover my bases. Also, just FYI, I have less than 1 degree of knock around my shifts with my current setup and none anywhere else. Could I go even lower than 3.3 on e85?

Might be able to. Just depends. Every car is different. E85 is a great knock fighter, might be able to get away with smaller, just depends. That's something you'll have to find out ;P

Yeah good call guys. I think that might be the plan to go with. I ran this all by my wife last night before I posted the question and suggested that exact thing, carrying an extra few gallons in the trunk. Her exact words were "extra gas in the trunk? That's janky". So yeah. Women...

Originally Posted by 91parkave

Better make sure that gasoline tank is air tight. E85 absorbs moisture fairly quickly.

it absorbs water from the air at the same rate as regular fuel does.