2021 F-150 Burble Logic

[M3T1]

For the life of me, I cannot figure out how to get the Burble logic in the Ford ECM to work. I started with settings from a 2019 Bullit Mustang. I had to modify a few things but I cannot get any burbles at all. I attached my file below for reference. Basically, I want light burbles in Normal mode and then heavier ones in Sport. I adjusted the Torque Clips, but I'm not getting anything. 0.150 is the value I use in my Mustang (Gen 2 so manual burble tune there) and it pops like CRAZY in that car until it hits fuel cut. Anyone know what I'm doing wrong?

Stock Burble.hpt

[Daddy1915]

just reduce the numbers in 44894 and 44895 and disable dfco.

[M3T1]

Isn't the whole point of the burble logic that you don't need to disable DFCO?

[Pistol_91]

You shouldn't have to. But if you're having issues. Maybe you should

[M3T1]

Does anyone know what the APP parameter is? The only thing I can think of is that I don't have the right values for that parameter.

[engineermike]

Accelerator pedal position

[engineermike]

I’ve messed with this until I was blue in the face. Basically you need fuel present and low timing for burbles. There is a minimum torque ratio set in the spark tr table for dfso. This torque ratio is generally set too high for burbles. Burble mode temporarily lowers the min tr in the right conditions and it works as intended. The problem I’ve had is that tr is used to reduce torque to whatever logic deems to be the desired deceleration torque. And if it reaches that torque before needing a very low torque ratio then it won’t command low timing because it doesn’t have to in order to reach low torque. So the next thing was to try to find a way to lower the target torque for decel, which is where I hit a roadblock. I haven’t been able to figure that out in hpt or pcmtec so I eventually brute forced it by lowering mbt in the specific load/speed/mapped point when I want the burbles to occur.

[M3T1]

I’ve messed with this until I was blue in the face. Basically you need fuel present and low timing for burbles. There is a minimum torque ratio set in the spark tr table for dfso. This torque ratio is generally set too high for burbles. Burble mode temporarily lowers the min tr in the right conditions and it works as intended. The problem I’ve had is that tr is used to reduce torque to whatever logic deems to be the desired deceleration torque. And if it reaches that torque before needing a very low torque ratio then it won’t command low timing because it doesn’t have to in order to reach low torque. So the next thing was to try to find a way to lower the target torque for decel, which is where I hit a roadblock. I haven’t been able to figure that out in hpt or pcmtec so I eventually brute forced it by lowering mbt in the specific load/speed/mapped point when I want the burbles to occur.

I was having this same issue trying to figure out how to slow down the DFSO entry and/or command lower target torque on my Mustang. It's a 2015, so it doesn't have the burble tables. I have a separate thread for that. This is good info though. I think I had the one of the APP parameters wrong because I didn't know what it was. I'm going to play with that tomorrow on my truck and see if that makes the burbles work.

[M3T1]

I got it. It was the APP enable parameter. I set that to 0% so that it allows for burbles whenever. Then I just use the RPM parameters to enable/disable. Seems to work now. One other thing I figured out is that the Lower Torque Clips in 44894 and 44895 act as a lower bound to the "Normal" mode burbles. So, you have to lower those if you want lower ratios than that for the Normal model burbles. The Sport mode burbles seem to disregard it no problem. In my case, I wanted the Normal mode burble ratio to be around 0.200 and the Sport to be 0.050. So, I had to lower those clips down to 0.200 for the Normal mode to work. They were set to 0.420 before, and it wouldn't go below that even if I set the Normal burble Target TR to 0.200.