dewilmoth

Wondering why there isn't much talk about flex fuel upgrades for the 997 Turbo? Is it not feasible with the ECM tuning solutions for the Turbo? I read several other forums, and it seems to be a very popular upgrade, especially for the GTR. The Turbo seems to be an animal on E85, but making the switch between 93 and E85 fool proof would be really convenient. Thoughts?

Edit: I am not referring to a standard E85 tune, I am referring to the ECU actively varying the tune/boost based on Ethanol content in the fuel derived from an Ethanol content sensor.

ecpchris

e85 is a viable option for the 997.1 turbos. Cobb tuning has flex fuelk capabilities and injectors. There are a few people running that setup.

dewilmoth

I've seen plenty of E85 builds, but never anyone on a flex-fuel setup. Hopefully someone that has the flex-fuel setup will chime in.

CincyScott

Most folks use flex fuel and e85 interchangeably. Are we talking about the same thing?

dewilmoth

We are not. Flex-fuel utilizes an Ethanol content sensor in the fuel line and allows the car to be tuned on E85 and whatever standard pump gas you prefer. The ECU then adjusts for the correct gas that is entering the motor. For example, if you have a tank that is half 93 and you add E85, the sensor will pick up that the content is now somewhere around E50 and adjust the tune accordingly. It never requires manually changing the tune, and theoretically you're car is always at max performance for whatever is in the tank. No more draining tanks and driving around with laptops. It is very popular in the GT-R world. Here's some reading: http://www.gtrlife.com/forums/topic/...iring-diagram/

therock88

Sounds like it is time to buy a Prius I think they can handle that flexibility....

DC

dewilmoth

Not sure what this has to do with a Prius. The goal isn't economy, it's horsepower. If you drive your car long distance and can't find E85, you can use premium unleaded and the car will still run correctly.

elite1

Being that I have converted my car to an E85 tune with Cobb, you are correct dewilmoth with the conversion to it. My wifes car is flex fuel ready and adjust to the correct mixture that the gas tank serves. Meanwhile, I run 1000CC injectors and have a certain map to run E85 with my car.

E85 is never consist with their manufacturing standards. I currently run E90 and pay $2.60/gal meanwhile, E85 (tested) is at $1.30. Changing from this E85 setup back to gas requires patience and knowledge of gas to ethanol content. Some have reported that a 50/50 mixture is okay to run on either map but, I personally have not tested this theory nor want to chance it.

I know Cobb has addressed this issue with GTR and will soon offer this for Porsche.

93ls1rx7

Currently need to use a standalone to do it. Switzer built a car for yumaverick using a Syvecs and he was set up with a true flex fuel setup. He since sold it and the new owner did a build using it.

ecpchris

Ah I got you know. Some people consider running e85 as flex fuel

I am pretty certain there are a couple Pro-efi guys running the flex fuel setup you are talking about. I believer Syvvecs as well

A418t81

As you stated, theoretically the car is always in a state of maximum tune, however unless you spend a very large amount of time tuning the car out at every 5-10% change in ethanol levels, it's really just a large extrapolation that the tuners use. My car runs on both pump and E85 and I just swap maps with the Access Port. I didn't tune the car out to the max on straight E85 intentionally, so I can swap from pump to E85 with a few gallons of 93 in the tank with no ill effects. When going the opposite way, a few gallons of E85 mixed with 93 octane does nothing but help the car out.

The car is still very, very fast on E85 but maintains a degree of safety since it isn't tuned on the ragged edge or for 85% ethanol. Truth be had, the vast majority of E85's ability to make more power over pump fuel is seen by around 50% ethanol levels....E85 only makes a bit more power over E50.

vr6tee

Yes, I am using the Syvecs with flex fuel sensor. It automatically detects the % of Ethanol in the tank and adjusts the map accordingly from 0-100% Ethanol. I'm currently at 83.7% Ethanol. There is no change needed on my end regardless of what fuel I run. No map changes to make.

Be aware though, I maxed out my 1300 CC injectors on 83.7% Ethanol. (855 whp)

proTUNING Freaks

Flex fuel sensor integration isn't possible today with the factory ECU. As @A418t81 mentioned tuning for E85 isn't an issue with the factory DME and E50 is usually where tradeoffs for power vs. fuel mileage end. For automatic scaling of the tune (flex fuel sensor based) you'd have to use a standalone. In a way its safer that way so that you don't suddenly forget and fill up with pump gas and run an E85 tune but really I am yet to hear of that happening for a customer. If its a concern a flex fuel sensor option is available with standalones such the AEM Infinity and Syvecs and works really well as well.

Dzenno@PTF

dewilmoth

Bummed to hear a standalone is required for flex-fuel on the Porshes. I've dealt with standalones before on other cars, and I would need to do some serious homework before opening that can of worms. Thanks for all of the great info guys.