[Juice247]

I know BM3's flex fuel option is right around the corner, but I was wondering if a flex fuel sensor and display would be a sufficient alternative to testing fuels and making sure your mix hits ethanol targets. How quickly does it get to an accurate measurement? Can you run the car for a min at the pump to get there or do you have to drive a number of miles? Testing fuel is a PITA and the only hurdle between running a 93 tune and unleashing those sweet drunken horses. Most of these kits have the CANBUS links that BM3 will eventually utilize anyways.

[G.Newt]

Test tube will always be more accurate (assuming you're bring precise), but the flex fuel gauge is convenient.

Unless you have the car or sensor running while you're filling up, you don't know until AFTER you've already pumped it (I think there's a company that makes a handheld E85 analyzer that would solve this problem). With the test tube, I know the E85 percentage beforehand.

[Juice247]

I've got the test tubes. Maybe I'll get the sensor setup and use it to learn how accurate my mixes are. Then I'll be setup for BM3 anyways. Testing, mixing, reflashing sounds super inconvenient. Especially in a daily driver....

[540iSUP]

On this same note, I was wondering if we could use say the Fuel-It flex fuel blue tooth analyzer kit and hook it up to BM3 canbus when the tune is available.

[johnung]

Originally Posted by 540iSUP

On this same note, I was wondering if we could use say the Fuel-It flex fuel blue tooth analyzer kit and hook it up to BM3 canbus when the tune is available.

Not sure what you are trying to accomplish?
I have the Zeitronix CANBus ethanol sensor installed with the Zeitronix E85 dashboard gauge. It uses the proven Continental sensor. It seems to be very accurate.

The government allows E85 pumps to actually contain as low as E49. Assuming that the pump actually contains E85 it's pretty easy to decide what percentage you want in the tank and pump in E85 and 93 to obtain it.

The biggest thing that I learned when the Zeitronix was first installed was that you can't add E85 and then fill up the rest of the tank with 93. The pumps all shut off with different sensitivities so the amount of 93 is inconsistent.

I use a phone app called e85Cal, and pump in the exact amounts of E85 and 93 that it calculates. This method has been dead on in ending up with the desired concentration of ethanol.

The Zeitronix sensor is located in the fuel line between the LPFP at the gas tank and the HPFP at the engine. Plus the gas tank is a split tank. So the new ethanol percentage doesn't mix instantly and make its way to the sensor just by starting the engine at the pump. But making a couple of turns to drive out of the gas station parking and down the road is enough for the fuel to mix in the tank and work its way to the Zeitronix ethanol sensor to provide an accurate reading on the dash gauge.

[eluded]

Flex fuel tune

Hoping bm3 releases soon.

[kern417]

Going to try to answer all your questions. More info in my video below.

- Test tubes will always be the most accurate if you're trying to target a specific blend. The flex fuel sensor will simply allow the car to adjust if your mix is off so you still can safely push the car.

- The sensor is only a part of the integration. You also need to plug it into the module that converts the sensor reading into the one the car can use, and then it plugs into a piggyback harness so the DME can see it. If you want to use a different sensor, you'll need to run the wiring manually and still purchase the kit so you have the box module.