Enable flex fuel with 800+ rwhp?

[GoPackers]

I've been combing the forum trying to learn as much as I can about flex fuel support in the E38. I have a car that is not flex fuel currently but it looks like I can flip the switches and turn it on. My intention would be adding the sensor so I could be safe with varying mixtures of ethanol, not using a COS with the switch or running a fake PWM signal instead of the sensor.

What I haven't found is anyone flipping on the flex fuel options on a big horsepower engine with forced induction. The problem I am trying to overcome is the availability of E85. There's lots of it around home but when I take a roadtrip with the car E85 coverage is spotty. It would be very slick to be able to tune for varying mixtures!

Has anyone had success doing this?

[Chevy366]

Try this ; http://forum.efilive.com/showthread.php?13171-E38-Flex-Fuel-On-the-fly-timing-and-fueling-anyone-interested&highlight=flex+fuel

[GoPackers]

I did read that, every post and every link contained within. That makes it sound like it's possible but before I put $10k worth of engine at risk I wanted to see how many people might have actually done something like this....

[GMPX]

What engine / year model is it? Some factory tunes are all ready to switch to E85, some however are not (eg Northstar V8's).

[GoPackers]

It's a 2009.5 (2nd half) Pontiac G8 with the 6L80E transmission.

[GoPackers]

L76 engine, 6.0L....

[GMPX]

Yep, that one should be fine. However, in Australia where that car came from people are fitting real ethanol sensors (also expensive), not the estimation routines GM typically use.

[GoPackers]

Yep, that one should be fine. However, in Australia where that car came from people are fitting real ethanol sensors (also expensive), not the estimation routines GM typically use.

That is exactly my intention... It seems like the best way to do it.

[Longslyde]

What I haven't found is anyone flipping on the flex fuel options on a big horsepower engine with forced induction. The problem I am trying to overcome is the availability of E85. There's lots of it around home but when I take a roadtrip with the car E85 coverage is spotty. It would be very slick to be able to tune for varying mixtures!

Has anyone had success doing this?

i know it is a little late but I just completed this today myself. 2010 GMC Sierra 6.2L Flex Fuel. E85 timing modes and sensors were turned off when I initially installed the Whipple Supercharger at 12 PSI. Completed tuning it this way and drove the vehicle for quite a few months. I got curious since all we have up here in regular gasoline is 91 and I had to use octane boost to thwart off ping, I decided to experiment with E85. All i can say is WOW! I should have sone this sooner. I loaded all the E85 tables and started tuning at a 50% mix of 91 octane and E85. All went well with some adjustments. went to 75% mix... Even Better! i am somewhere around 95% mix of E85 today and it runs GREAT! E85 LOVES forced induction! Zero Ping! Instant response and much better torque and horsepower throughout the whole power band. Yes it does use more fuel when you're on it hard. But not as much of a difference as I thought there would be due to the fact i had to be really conservative on the timing with regular gas and I can command alot higher timing when using ethanol. I'll live with the 2 mile per gallon loss since it costs me less in the long run and alot more fun to drive. The beauty part of this is I can fill it up anywhere now without having to worry about making any adjusments! Just make sure you have good logs to make sure nothing goes too far out of tolerance for you. Especially watch injector duty cycle and pressure. Take care and have fun!