Where to Start Tuning an LF3?

[RSTinOKC]

I've owned HPtuners for 10 years or so but my experience with it is limited to GEN III V8 and I'm rusty even with that.

I've owned a 2014 XTS V-Sport (LF3) for about 2 years now and after my first time taking it to the track last weekend I've decided to try to tackle tuning it with the primary goal of being able to hold 15-18 psi boost at a more constant rate than the stock variable 12-15 psi, and to actually learn about and understand what I am doing along the way while keeping my chances of catastrophic failure to a minimum.

I've parsed a few threads here on the LF3/LF4 platforms and have already gleaned some good information. At this point I am wanting to start with the basics of eliminating KR (of which there is a horrible amount in the stock tune), getting LTFT/STFT's dialed in, and tuning the MAF's.

As earlier stated, my experience is limited to GEN III V8; how much of that tuning process translates over to the LF3/4 platform? I've already begun the process of eliminating KR but not sure if some of what I am seeing at heavy acceleration and WOT is TCS related or not.

Attached is a log of mixed driving on the stock tune, and my current tune that is my first attempt at getting rid of the KR observed in the log.

Any pointers on where to start or reading recommendations are greatly appreciated.

[cadillactech]

I've owned HPtuners for 10 years or so but my experience with it is limited to GEN III V8 and I'm rusty even with that.

I've owned a 2014 XTS V-Sport (LF3) for about 2 years now and after my first time taking it to the track last weekend I've decided to try to tackle tuning it with the primary goal of being able to hold 15-18 psi boost at a more constant rate than the stock variable 12-15 psi, and to actually learn about and understand what I am doing along the way while keeping my chances of catastrophic failure to a minimum.

I've parsed a few threads here on the LF3/LF4 platforms and have already gleaned some good information. At this point I am wanting to start with the basics of eliminating KR (of which there is a horrible amount in the stock tune), getting LTFT/STFT's dialed in, and tuning the MAF's.

As earlier stated, my experience is limited to GEN III V8; how much of that tuning process translates over to the LF3/4 platform? I've already begun the process of eliminating KR but not sure if some of what I am seeing at heavy acceleration and WOT is TCS related or not.

Attached is a log of mixed driving on the stock tune, and my current tune that is my first attempt at getting rid of the KR observed in the log.

Any pointers on where to start or reading recommendations are greatly appreciated.

Spend a lot of time reading the GEN V V8 forums as they are roughly the same ECM configuration. This is a torque based ECU that is not like a GEN3 LS ECU much at all.

Spend some money on Greg Banish's Calibrated Success training if you are still lost.

That being said, if you are rusty on GEN3 stuff, a twin turbo direct injection torque based platform isn't the best thing to start experimenting on unless you have deep pockets.

The LF4 has different internals so don't think you can push the LF3 as far as the LF4 can be pushed with stock internals.

[RSTinOKC]

Spend a lot of time reading the GEN V V8 forums as they are roughly the same ECM configuration. This is a torque based ECU that is not like a GEN3 LS ECU much at all.

This advice is very helpful. Most of what I've read so far has been pointing me to the 2.0T threads and LNF Bible. The GEN V suggestion makes a lot more sense, much appreciated.

[cadillactech]

This advice is very helpful. Most of what I've read so far has been pointing me to the 2.0T threads and LNF Bible. The GEN V suggestion makes a lot more sense, much appreciated.

Those are all very similar ECUs in that they use airflow to estimate torque and torque to control many ECU functions unlike the earlier ECMs

[RSTinOKC]

I'm going to spend some time getting my scanner set up properly and getting reacquainted with that end of things.

I happened upon Goat Rope Garage's YouTube channel last night and he has a great series of HP Tuners 101 videos that are going to be super helpful in getting me re-familiarized with some basics. It appears that most of his stuff is Gen IV based but mentions Gen V also which has already been helpful with my transition from the LS end of things. The Calibrated Success vids are on my list also as well as a wideband.

Any recommendations on a portable wideband? Is the Innovate LM-1 still a thing and are portable units any less accurate than installed units?

[cadillactech]

If you are a hobbyist then the AFR 500 is a good buy.

Spend some time logging and understanding why the stock system does what it does before you go attempt any changes.

Understanding how the ECU estimates and calculates torque, why and where the torque limits come from will help you understand what is going on.

[RSTinOKC]

Just an update - I found the E39/E78 help file and it has been super helpful in understanding the torque based control structure. I'm currently setting up configs for logging help file suggested parameters.

[RSTinOKC]

@cadillactech here are two 0-80 wot logs. When you have a minute will you please review and advise as to where I should be looking as far as torque limiting is concerned? I do see at the end of both logs near the 80 mph mark it appears TCS becomes activated but I am not seeing throttle closing or boost limit anywhere. There is some KR noted as well but I'm not sure it isn't torque limit related. If you need my channels config let me know. Feel free to PM me if you prefer.

Edit: the in dash boost gauge is showing 10'ish psi max and holds fairly well.

[cadillactech]

I am seeing almost 5 degree KR on both of those logs. This needs to be addressed first.

Do you have a wide band hooked up? I do not see one in your logs. You absolutely need to know what lambda the engine is running under WOT.

I would pull some timing out at those areas that are showing knock and see if it goes away and monitor lambda to see where you are at.