I know people are converting to e85 all the time, and ive read many threads on it. my main question is with an e85 conversion can they run both e85 and gasoline? i was under the impression that they cant which made me wonder how any newer flex fuel engine does it. is it all in the computers and programmable injectors and such? what makes a flex fuel engine different than a regular gasloine engine, and is this doable in an 5.3 turbo swap in our thirdgens?

 

That's pretty much it... the injectors have to be big enough to flow 75% more fuel than they would with pure gasoline, and the ECM has to be smart enough and have enough "range" in its "thinking" to vary the fuel constant over a similarly enormous range.

Most of the time, when you see people "convert" to E85, they're taking a carb or other system with much less real-time adaptability, and just changing it to flow more fuel. IOW, it will no longer run on gasoline, because the motor would drown in it.

For a swap, using a "flex fuel" ECM to start out with and WAY HUGE injectors, it should be possible... a "flex fuel" engine can't really see the sheet metal wrinkles, and therefore shouldn't get too shook up about being in one of these cars instead of in a Burb or something.

 

i dont understand what you mean by they shouldnt be shook up about being in one of these?

i also read on a little more and they have a sensor that read the amounts of ethanol or gasoline in an engine, is this true? if so what other sensors are there that make flex fuel possible.

i know most of the flex fuel capabilities have to do with the engines computer but can a flex fuel vehicle be retuned to accept H/C/I mods or power adders such as turbo, nitrous or superchargers?

last question for now. i did know that e85 injectors need to flow 75% more than a gasoline engine, but if you plan on modding an engine you need more fuel. needing more fuel on a gas engine means you need way more fuel for an e85 engine. but can you go to any regular injector, or do you have to buy one that can change the amount it spits out when the ecm tells them they are running gas or e85?

 

What I mean is, if the "flex fuel" feature worked when wrapped in one variety of sheet metal, then just changing the sheet metal it's wrapped in, won't scare it into not working. This is in reference to

No there is no sensor that measures anything directly about the fuel... only one that measures the result of combustion. And if that one tells the ECM that it needs more fuel, then the ECM adds more fuel. Only thing is, the rest of the fuel system has to be able to deliver that fuel. But furthermore, it has to be able to deliver the lesser amount of fuel as well, when that's appropriate; and, it has to be smart enough to be able to handle this MASSIVE variation in fueling requirements without giving up in despair and considering it an error condition.

Spend some time on fullsizechevy.com, ls1truck,com, etc. Since what you're talking about is unwrapping the truck from around one of those motors and re-wrapping the motor with some other body, which doesn't materially affect the motor, that's a more likely place to learn about those motors from.

 

ill check out ls1 truck. i didnt come up with much on FSC