So im all about physics and chem but there is something i wonder.

Whats makes a car flex fuel frendly? Doesnt e-85 burn hotter?

So what do we have to do to our stangs to make them E-85 capable?

E-85 is a dollar cheaper here than Even regular unleaded.

 

E-85 has a lower BTU per unit than regular gasoline. In other words, you have to spray more fuel to keep the engine happy, making as much power, and not detontating.

E-85s major advantage, other than the supposed enviromental one (not sold on that) is that it has a much higher octane rating than regular fuel. Some really built cars run E-85 with a much larger than regular fuel pump (to keep up with increased demand) but instead of running race gas they can run the cheaper e85.

The disadvantage of running it is that even though it is cheaper, it is not as efficent, and it will get poorer MPG.

 

Yeah im an hvac tech (my job before this one and what i do on my days off) so i know all about BTU's and fuel and that good stuff. But can our cars run it safely. Like say someone like me or you who have built motors where we both in our own ways require high octane. So i guess even though its cheaper ur gas mileage will fall. Will my fuel pump/injectors be able to keep up?

 

I have HEARD that it has a tendancy to eat up rubber, but then I have also heard that its BS.

You would need a retune (for best results with someone that knows something about E-85), bigger injectors and fuel pump for the same horsepower level. I would expect to see MPG to fall but you would be able to run more agressive timing without detonation.

I guess it all depends, its not really all that common of a mod yet, and your going to have trouble finding someone to tune the car. Unless you could always run 85 you would need 2 new tunes, one with the 85 and one with regular fuel setup for the new injectors/pump. And unless your either running fairly high compression or fairly high boost levels, its not really going to help that much (if your not going to get an advantage from timing its not going to do anything for you).

I am not 100 percent sure you wouldn't have to modify anything else... I have never done it, and am speaking from stuff I have read in magazines and on the net.

 

Well im running 10.5:1. I think with 24#'s maybe that would do it. . . But you're right im not sure too many ppl know too much about it yet. But i guess if your MPG drops down the fact that it's cheaper wont really help. Im not really willing to take a chance and try with the fact that i just spent a ton of money on my new motor. Just curious though.

But why would i need two different tunes?

I mean you dont change tunes on a flexfuel vehicle when you put in different types of fuel. Or does it have a special kind of octane sensor that knows. . . .and adjusts accordingly

 

you wil definitly need a bigger fuel pump. and possibly bigger injectors. i have also heard e85 eats rubber over time. people who switch over usually get new fuel lines.

 

I would think that "flex fuel" vehicles would just have a wider range of adjustment in the ECM program along with the bigger injectors and fuel pump.
Wide range O2 sensors or something maybe??????[>:]

 

unless your planning on forced induction i see no reason as all you would be able to do is advance your timing for an increase of like 8 horsepower. your talking switching a grands worth of fuel system for 8 horsepower. i do however believe it would be worthwile on a FI car. more boost more timing = lots of horsepower.

 

The point is not to get more power. Its becuase E-85 is a dollar cheaper than unleaded.

 

E85 is, as we all know, 85% ethanol(in the summer. It drops to about 70% in the winter because they say a vehicle starts easier in the winter with 70%) and 15% Gas. It comes out to an octane rating around 96-105. Ethanol has an Oxygen molecule attached to it, thus needing less oxygenso it burns richer and shoots the hell out of your mpg. Also a flex fuel vehicle has special liners in the tank and fuel lines because ethanol is corrosive and will eat away parts if they're not designed for it. I have a Moutaineer that's flex fuel and after 2 tanks of it I stopped running it. It was cheaper to run and the exhaust smelled like you were burning racing fuel but I went from 18mpg in town to 10. So all in all I was actually losing money by running it.