Q/A: FI FLEX FUEL TUNING
 

So, TUNING FLEX FUEL. Been reading up alot and learning but I have a question that I havent found an answer to and I might just be missing it or simply overthinking it. The flex fuel mapping does all of its ignition, fueling, boost control, etc. on the fly by means of the ECA, yada yada.

So my question... for those of us running OFT closed loop boost control, I guess ebc could be a question too but that can be adjusted easily, how exactly is it that when the eca analyzes the content and adjusts your map to the safest boost limit for that content, how does your wastegate also adjust to that limit as well? I mean with a normal tune you adjust your preload to get to your target psi that you have in your tune to match boost, fueling, timing and not make engine go boom.

But with flex fueling you can have varying boost limits that adjust all those variables on the fly and if your preload is adjusted (say 10psi) and your eca adjusts map values to 8psi max for lower ethanol content your closed loop boost is still set to reach 10psi while your ecu is only delivering fuel and timing variables for 8psi this is not safe. Same goes for content over 10 psi then youll run rich as well as losing potential performance.

I apologize if these questions are stupid and dont make sense to you or is some simple dumb answer im overlooking but im fairly new to it and trying to learn it before 1. Shiv finishes his flex kit for OFT and 2. I install it. Thanks in advance guys!:cheers:

I recommend you get an Ecutek tune and handle it all with their custom maps slots.

Im not sure how thier doing it maybe ask shiv since your buying or have their kit.
Possibly electronic boost controller, pretty sure ztan who wrote the flex code has one, and the guys here running high boost brzedit tunes cars use those ebc and are runing power over 300kw on e85, without ecutek, so its possible.

Cutting corners and costing engines really worth all the hassle not to use ECUTEK?

Yeah cuz that's what shiv does, cuts corners...

Just because someone is innovative and doesn't do what you do, doesn't mean it's any less reliable. I'm talking about a flex kit and what kind of BC is needed with it, ecutek doesn't really have anything to do with it, that's just a tool, you still need a tuner to develop your map through another program. And ecutek is just a means of integrating that into the vehicle, same as OFT (which is also all the necessary gagues incorporated in one device).

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I won't speculate about what other companies are doing, since I'm not following their progress. However, I can say that it would likely be tough to one up ECUTek in terms of functionality. Unfortunately, some owners are under the impression that ECUTek's RaceROM features only adds launch control, FFS, and other novel functions, but this is far from what it's capable of in the hands of a pro tuner.

ECUTek's RaceROM gives the tuner the ability to utilize 16 custom maps to take variable inputs to create custom functions that the factory ECU was not ever intended to do. They've essentially re-written the factory logic to implement these custom features.

I will generally use every map available to write my own custom functions for flex-fuel control, such as:

Closed loop boost control
Boost based on ethanol content
Boost cut based on ethanol content
Boost by Gear
Boost by map switching
Boost by water temperature range (hi and low)
Boost by oil temperature range (hi and low)
(all boost functions work together at once and are all under closed loop boost control on the same flashed ROM)
Closed loop fuel target map and WOT correction based on WB 02 input, etc, etc.

Let's put it this way, if you wanted to create a crazy function where the throttle plate is limited to 50% on left hand turns and a rev limiter of 5k rpms is implemented on right hand turns, this would be possible with ECUTek.

At the end of the day all tuning software is just that, software. There is nothing tangible for the end user to pick up and look at. It's what the software is capable of that makes the difference.

- Toan

:clap::clap::clap::clap::clap::clap::clap::clap:

And I don't disagree on ecuteck's functionality at all. Simply saying that it's just a tool. Same as OFT. Now yes ecuteck may have more features of tunability but not all people need that. OFT in the right hand gives street and daily drivers just what they need, without excess guages. Now the reliability of the tools in question are not of themselves but rather all in the hands of the tuner that uses them. Only point I was trying to make. And if someone believe shiv is unreliable... GTFO

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Did someone say flex fuel?

https://lh3.googleusercontent.com/-t...1600/flex1.png

To answer your question for how they adjust timing / boost for flex content on OFT, "you can't". Flex fuel with OFT doesn't currently exist. Sure Shiv is working on it, but not a single customer car using OFT has it running right now. Its just not there, yet. And even when it IS there, he is re-purposing factory maps to replicate the flex fuel functionality. Until he or ztan is able to set up custom maps, OFT doesn't even come close to Ecutek from a tuning perspective.

Ecutek makes this easy. You build a reference map for E% by rear o2 voltage, then use that as your reference to tell the car how much fuel to put in. Its all done by selectable options in Ecutek. Mine is set up exactly as Ecutek recommends in their docs, but picture below. Its super easy to implement the base flex fuel functions in Ecutek. Save yourself a ton of headache and just go Ecutek if you want flex fuel support.

https://www.ronkh.com/clientimages/L7f8b1w3J7U3I8.png


Regarding boost control, same thing. You take engine RPM and E% from your initial rear o2 to e% map, and set that up in a custom map to set the CPC duty percentage. You have CPC going to a boost controller, so your CPC duty is your boost control percentage now. You can save a map by referencing rear O2 directly versus wasting a map on determining E%, but that is a different discussion.

That is just the start of it. So many things are possible with Ecutek's custom mapping. The only thing I dislike is that you're limited with how many custom maps you can set up. You can reference values from many different things to use as inputs to your map. Here is a taste, below is everything your Ecutek tuner can reference to create custom logic and safeguards in your tune as @ptuning described.

Your front and wheel speeds don't match? Set up a custom map using these inputs to modify timing, boost control, etc to reduce power output. Scale your map so that the more you spin, the more timing / boost it pulls, and once you're not spinning the logic is ignored again. You can even set thresholds so the logic isn't applied immediately and is delayed. This is just an example. Ignition traction control isn't ideal, but again, different discussion.

https://www.ronkh.com/clientimages/F7l2s5F5l8W7y1.png


I promise this isn't an Ecutek sales pitch. When it comes to down to keeping things running right, Ecutek simply shadows OFT in comparison. A good tuner can utilize Ecutek to limits far beyond OFT will ever reach. I'm a mostly DIY tuner, who started off on this car using a tactrix cable to flash the OFT maps edited via RomRaider. Once I got my feet wet I switched to Ecutek as the benefits are just so vast, it doesn't make sense to not use it. Unless you're going standalone of course. :D