Driver Demand question

[jtrosky]

So I've been trying my hardest to address one last remaining issue I have with my 2012 Impala tune - the dreaded "clunk" coming from the driveline when reapplying the throttle after coasting/braking at low speeds (12-37mph mainly). After trying everything I could think of, I never could completely resolve the issue.

So I resorted to "drastic" measures, which so far seem to work 100%! However, I want to make sure that I won't cause any long-term issues using this method.

Basically, what I did was to put a VERY small positive value (0.02 -> 0.05) in the 0 pedal row of my Driver Demand table for the problematic speeds. My theory is that by keeping a VERY minor amount of "pressure" on the driveline at the problematic speeds, that it will basically "take up the slack" in the driveline, so that when I reapply the throttle at those speeds, the drivelone "clunk" is eliminated and all is smooth.

So far, so good - assuming that things keep going as they are, are they are potential long-term issues by having a VERY low positive value at the 0 throttle position in my Driver Demand table? Again, keep in mind that the values are EXTREMELY low (.02 -> .05) - it's certainly not enough to actually cause the car to speed up on it's own or anything....

Thoughts?

Here is a pic of my current driver demand table:
JT_DriverDemand.JPG

[ayousef]

So I've been trying my hardest to address one last remaining issue I have with my 2012 Impala tune - the dreaded "clunk" coming from the driveline when reapplying the throttle after coasting/braking at low speeds (12-37mph mainly). After trying everything I could think of, I never could completely resolve the issue.

So I resorted to "drastic" measures, which so far seem to work 100%! However, I want to make sure that I won't cause any long-term issues using this method.

Basically, what I did was to put a VERY small positive value (0.02 -> 0.05) in the 0 pedal row of my Driver Demand table for the problematic speeds. My theory is that by keeping a VERY minor amount of "pressure" on the driveline at the problematic speeds, that it will basically "take up the slack" in the driveline, so that when I reapply the throttle at those speeds, the drivelone "clunk" is eliminated and all is smooth.

So far, so good - assuming that things keep going as they are, are they are potential long-term issues by having a VERY low positive value at the 0 throttle position in my Driver Demand table? Again, keep in mind that the values are EXTREMELY low (.02 -> .05) - it's certainly not enough to actually cause the car to speed up on it's own or anything....

Thoughts?

Here is a pic of my current driver demand table:
JT_DriverDemand.JPG

problems? not at all, you could even go negative at higher speeds in the 0 pedal area. My 0% pedal area is either zero's or negative values. Look at how the C7 Z06 table is setup for reference as well. But take into consideration that the VSS values you see are always in KPH and not MPH regardless of what your unit settings are set at (imperial or metric).

[jtrosky]

Yeah, I quickly learned that the Driver Demand tables were in KPH! :-) I undertstand that negative values aren't an issue, but was wondering if having positive values in the 0 pedal position could cause any issues since the computer is not expecting positiive values when you're not pressing the pedal. Wasn't sure if it could cause issues with traction control and/or ABS, etc....

Thanks for the reply!