[mike@x-ph.com]

I’ve always believed that a flex fuel kit isn’t necessary when running OTS maps if you’re not concerned about the additional features. OTS maps are conservative enough that even if your ethanol mix isn’t perfectly accurate, you’ll still be fine since they’re designed to safely handle slightly lower octane levels.

While data logging on OTS maps isn’t mandatory because of their safety margins, it’s always recommended to do it at least once. The challenge with data logging is that it only captures how the car performs at that moment. If your ethanol mix changes down the line (the gas station’s mix varies), you won’t know unless you keep data logging regularly.

For example, I was running the Bootmod3 E50 map, and based on calculations, I filled my empty tank with 7 gallons of E85 and 6 gallons of 91, expecting the mix to be E50. Here’s the math:
(0.85 × 7) + (0.1 × 6) = 6.55 / 13 = ~E50

Yesterday, I installed the PTF flex fuel kit on my car and was surprised that the ethanol mix wasn’t even close to E50, but around E35. The “E85” from my gas station was closer to E50 than E85.

This means I had been running a more aggressive map than my fuel could support. As a result, I was likely losing power due to timing drops and, more importantly, risking serious engine damage.

Fortunately, nothing catastrophic happened, but this experience has made me a firm believer that anyone running E85 with any map should install a flex fuel kit, even when running OTS maps. It’s the best way to ensure your ethanol mix is correct, make max power and avoid damages.

Side Note: i also flashed my car with Bend Calibration flex fuel map, and its very impressive. i will have seperate threads in the future discussing Bend and the PTF flex fuel kit, but wanted to give you guys heads up on this experience.

[RCKYMTN M34OI]

Flex fuel kit is a really great option and easiest way to monitor E content. Before I had a sensor I would test the "E85" with a manual ethanol content tester to see what the true value was and calculate my mix from there. I found a couple stations that were consistent.
So there are work arounds to getting a sensor but definitely takes more effort and vigilance.

[altspacen]

For me, this will be my next big step when it comes to tuning my car. While I like having a sensor and knowing, I'd much rather have a turnkey answer that can communicate and adapt the map on the fly. Once I'm ready to make the jump from my stock car w/JB4 (running 93 only), it'll be a system that can handle reading and adapting on the fly to changes in E content. Keeps me from being stuck to a single gas station that's 30 minutes away and gives me the peace of mind if the wife decides she wants to take the car and fill it up with straight pump.

[mike@x-ph.com]

Originally Posted by RCKYMTN M34OI

Flex fuel kit is a really great option and easiest way to monitor E content. Before I had a sensor I would test the "E85" with a manual ethanol content tester to see what the true value was and calculate my mix from there. I found a couple stations that were consistent.
So there are work arounds to getting a sensor but definitely takes more effort and vigilance.

Originally Posted by altspacen

For me, this will be my next big step when it comes to tuning my car. While I like having a sensor and knowing, I'd much rather have a turnkey answer that can communicate and adapt the map on the fly. Once I'm ready to make the jump from my stock car w/JB4 (running 93 only), it'll be a system that can handle reading and adapting on the fly to changes in E content. Keeps me from being stuck to a single gas station that's 30 minutes away and gives me the peace of mind if the wife decides she wants to take the car and fill it up with straight pump.

i always thought that even if its not 100% accurate, i should be pretty close. i never imagined its off by 35 points, lesson learned, im just glad no harm was done