E85Forum.com

zgiles · Joined: 15 May 2006 Posts: 2

Hey guys, new to the forum here.

I'm wondering about E85 in a chevy cavalier 2005, 2.4L I-4
It's not FFV but from what i've been reading it seems to be near
compatible...i think? anyone on that one?

Anyway, from what I understand, in modern cars, the only major thing that needs to be changed to use E85 is the air-fuel ratio (and thus the injection size), am I correct?
Just need to have that clarified..

So, other than that brazilian Flextek device, (which i think just changes the ratio after the ECU), is there good device for doing this?

hotrod · Joined: 19 Apr 2005 Posts: 872 Location: Colorado

Welcome to the forum!

Have to wait and see if anyone here has done a conversion with your car.

In general your right, you need to add about 27% -30% more fuel flow. There are lots of different ways to do that, depending on your goal ( ie permanent full time conversion to E85 only --- home brew FFV with some user intervention when you switch from gasoline to E85 or just using a high ethanol blend).

There are no "conversion kits" available due to the way the emissions regulations are set up, but lots of folks have worked things out on their own.

Spend some time browsing the forum and searching for topics of interest and you will see quite a bit of info is out there in the forum threads. You will come up with more specific questions when you see some of the ways different folks have tackled the problem.

Larry

chenely63 · Joined: 09 Aug 2005 Posts: 27

been useing the flextex unit on a 1996 ford ranger 2.3 L
works great and simple to install
Leo

zgiles · Joined: 15 May 2006 Posts: 2

hmm. I hope someone has converted one of these before. I'd be interested in seeing how it turned out.

This flextek device...it seems to just control the timing. I dont mind giving them money, but it is pretty expensive for me..I'll search the forums, but also pose the question here:
Is there any other way of doing the same thing with cheaper stuff? DIY device or soemthing?
been looking around and having trouble finding something.

ender · Joined: 12 May 2006 Posts: 15 Location: minneapolis

i'm new here too Very Happy

there are a few ways to increase flow, but the easiest ways tend to screw with other aspects of engine management.

the easiest way would be to use a potentiometer tied to 5V (or whatever voltage is for max flow- some denso AFM's go backwards) on the engine's main load sensor to show the ECU more engine load to increase fuel flow. this would be either the MAP sensor or airflow meter (this will be tougher on hotwire MAF and karmann vortex cars though, you may need an S-AFC). more load=more fuel. the real caveat here is more load also=less timing, which is the opposite of what you want with E85. it'll get you the fuel, but you'll lose performance with the loss of timing. you may be able to make up for it by physically advancing the timing, but cavaliers are DIS engines so the only way to do that would be to manipulate the cam/crank position sensors. not the best way IMO.

another method would also utilize tricking the load sensor, but doing it by adding an additional injector to the intake tract to add ~30-35% more fuel under all conditions then LEANING the load sensor signal out to get the fueling correct. this will also advance the ignition timing slightly. you don't want to lean more than a few % though or you may add so much timing that the ECU can't pull enough out to stop detonation. the advantage to doing it this way is not only the added timing, but the fact that you can set the fuel controller to be switched to the extra injector driver (a basic darlington switch tied to one of the stock injectors will work perfectly) so that when the tank is empty and you want to run gasoline again, you just flip a switch and you're good to go- it turns off the injector driver and unfilters the load signal to return to stock fuel/ignition. just make sure you can't bump the switch. i may try this method on my car.

i've read about others on here jacking up fuel pressure. this can work, but remember that to double the flow, you have to quadruple the pressure. most stock fuel pumps drop off dramatically in flow above 60psi. there are a few that can work though- aftermarket walbro high pressure pumps or the denso toyota supra/mitsu 3000GT pump if you don't want to hear the pump whining all the time.