E85 or meth?

[MattO]

Injected

[novahollic]

I'm assuming LS engine? What ECU are you running? If you can make it a true flex fuel car, like you can with the newer factory ECU's, then you don't have to worry about having e85 available all the time.

[Flash68]

Yep, Stielow posted about making XV (and maybe the update to Jackass?) E85 compatible.

[MattO]

Nope, no LS for me. I'm not that smart. No, instead I built an Atlas 3.5L inline 5cyl engine that came in my GMC Canyon. It rocks a P12 ECM which is only just a hair better than a Texas Instruments calculator. So yea, I'm kind of an idiot...

[novahollic]

Not an idiot. Just working with what you've got. Does the P12 ECU not have Flex Fuel capability? I think most 05-newer car do. If you post up an HP Tuners file for the truck I can check.

The problem with running a strictly e85 tune is that you don't always get 85% ethanol in your fuel. If you end up with 70% ethanol, you be running too rich all the time. If you install an ethanol gauge you can monitor it, just so you know where you're at.

Or you can run e85 "race gas", but that defeats the "poor man's race gas" idea behind it.

[Flash68]

Originally Posted by MattO

It rocks a P12 ECM which is only just a hair better than a Texas Instruments calculator. So yea, I'm kind of an idiot...

Nice.

Originally Posted by novahollic

The problem with running a strictly e85 tune is that you don't always get 85% ethanol in your fuel. If you end up with 70% ethanol, you be running too rich all the time. If you install an ethanol gauge you can monitor it, just so you know where you're at.

Or you can run e85 "race gas", but that defeats the "poor man's race gas" idea behind it.

Since you, MattO and I are in Norcal, we should not have a problem with the summer/winter blend deal E85 users face in other parts of the country. My research before choosing to go E85 on mine showed Norcal pump E85 has been very stable in the 85-90% range year round, at least that was the case when I dug into in this a year or so ago. I have the Quickfuel test tube and will be checking each batch of fuel.

FWIW, some pump E85 I bought in Concord in late 2013 registered 88%... I had some leftover after the dyno and I decided to test it a month or so ago and it registered 84%.

[Neil B]

For blower cars, the trick is to keep IAT's down using water/meth. Octane enhancement was secondary. Adding a secondary fuel source added tuning challenges and the need for fail safes in the tune. Nitrous is also a good way to cool the intake charge.