I've seen plenty of engines blow because of cheap injectors sticking, cheap injectors not being consistant, etc etc etc..... so you could spend a little more now, or possibly rebuild an engine because your injectors puked.

Not so much..... if you tune your car with a tank of e85 that is actually 85% ethanol, then go out and beat on your car and tank up with 70% ethanol..... where's your margin or error there? The OEM's know about this, which is why they have a sensor that will alter the fuel and timing maps based on the amount of ethaonal content.

The n/a plates aren't much thinner in the affeced area's than the earlier 13bt's.... there's no limit if the tuning is good. If you're worried about it, stud it.

Problem solved... :)

http://www.zeitronix.com/Products/ECA/ECA.shtml

I could stud it, but I don't plan on making over 400hp or having a ridiculous tune. It's a street car and anything over that probably isn't a good idea.

All that does it take the 0-5v signal and use it to display a number. It's just like a wideband except it displays a different number. The thing to to would be to wire it into the ECU to automatically alter the fuel and timing maps.... my Motec will do that... can a haltech or squirt do that?

You mean I shouldn't waste my money on a $200 cool screen? :)

I believe the e6k can. It has two inputs that can be hooked to trim modules. I just skip the trim module and have it go straight to the input. I think it can do about +- 10% fuel with the trim. Or just +8 deg timing. I'd have to look at the manual again.

Here some decent info on the sensors and how to reverse engineer them to work with most standalones.
http://www.megamanual.com/flexfuel.htm

I've been thinking about this... If I tune for E85 and actually get E70 in the tank, won't it just run a little rich? Also, most of today's pump gas varies in ethanol content. Presumably not 15% like E70 to E85, but it's still a variation.

Also, apparently the flex fuel sensor modulates the frequency and pulse width of the output to represent the ethanol content so I would need the Zeitronix (or some other) interpreter to change it to 0-5v output.

I'm not so sure about the fuel sensor... You MAY be able to use the trim module input, with I think looks for a different voltage to determine its position, but you'd need way more that 10% to adjust for E85

I came to same conclusion. Engine tuned for E85 would run about 9% richer with E70.

Also, I have very recent study which examines effective octane number of ethanol and several blends with gasoline. What is awesome about this study is the fact, that it separates effects of evaporative cooling from true, so called effective octane, which is based purely on chemical antiknock properties of given fuel.

Simply said, ethanol-gasoline blends, even with very low octane gasoline as base, have peak chemical knock resistance at about 50% volumetric ethanol content and any more ethanol content just increases cooling effect.

This brings another phenomena, for given air temperature, lower ethanol content fuel realizes more of theoretical charge cooling effect and vica versa.

So effectively, as far as knock resistance goes, E85 is no better than E70 or E50, unless the intake temperatures are over 100°C.

The trim on the e6k looks for 2.5v. Anything over increases whatever setting up and below goes down. I would only use it for adjusting for e85 vs e70 or what not. Going from e85 to pump would definitely require a different map.

What happens, and I have tested it. In winter you get less reid vapour pressure from E85 so they sell you E70. In terms of 'tune' the car is now running richer, so if you tune for 0.78 lambda in summer with E85, in winter you get ~0.7 lambda from E70 and you make more power in winter...

What is bad however is that your car idles and cruises like a bucket of shit until you adjust the mixture in the idle /0-3000rpm band.

while i don't always share your opinions, i've always been a fan of yours Rice. i think you should be a mod! it would be great seeing you make foreskins cry before banning them.

on a sidenote: my sister and i started calling unsavory people foreskins instead of dicks a while back because we thought "dick" was too much of an honor to them.

I appreciate telling it like it is, but I would personally hate to see a narcissistic moderator who thought only their opinion is the correct one. That's one reason I left rx7club...

I'd rather have an "opinion" backed up by testing and real world experience than a bunch of theoretical "knowledge" based on theories and postulates that may or may not actually work when the rubber hits the road.

However at the end of the day, its just the internet...

I totally agree, but it's not the only opinion with testing and real world experience backing it up.

Well, from what I have read thus far, the level of performance achieved and the quality and detail of the documentation trump that of those with whom he chooses to disagree so.......