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[ECUTek] [STI] Air / Fuel correction on stock ROM

Practical Reflash Tuning

Discussion and questions related to the course Reflashing

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Before making any modification to my car and ECU I've decided to log out the current ECU behavior. The car is a 2015 STI and I'm using ECUTek.

I've attached a 3K cruise control log and have a few questions:

1. Is Air/Fuel Correction #1 is the Short Term correction?

2. Is Air/Fuel Learning #1 is the Long Term correction?

3. I've seen -5.5% on AFR Correction #1 and an area of -4.7% on AFR Learning #1. Is that valid for a Stock ROM? the example on the course are saying that we should stay at around +/-2%.

4. In the BRZ course there's a Commanded AFR ratio, but I cannot find it in the STI parameters. Is this not available?

Thanks in advance!

Attached Files
  • STOCK-ECM-af590_0000-enc-AZ1N100G-10-11-2018-00-52-27-3k-cruise.csv
  • Attachments may only be downloaded by paid Gold members. Read more about becoming a Gold member here.

Hi Roman, please see answers below:

1. Yes, Air/Fuel Correction is essentially STFT.

2. Yes, Air/Fuel Learning is LTFT.

3. This isn't uncommon for a stock vehicle but before taking too much from these numbers you need to consider if the engine was heat soaked or under unusual operating conditions at the time since that will require more work from the closed loop system. Ideally we'd like to get this within perhaps +/-2% and I won't be unhappy provided we're within about +/-5%. The closer the better but it's important to understand that you'll never get absolute perfection so don't beat yourself up too hard.

4. Your AFR target tables should be visible under the Open Loop Primary fuel tables. Post up some screen shots if you can't find these.

Thanks Andre.

Re #4 - I'm actually referring to the Target AFR logging parameter.

I'm attaching the list of all the available logging params. Does it make sense that it is not available? From the BRZ course, I understood that this is very helpful when tuning Open Loop.

Attached Files

Ah sorry now I understand. Not all parameters are available in all vehicles. While it would be nice to have the ability to log target AFR that's not always going to be an option. A work around here is to target a fixed AFR under open loop conditions so you'll always know what this target is going to be.