Originally Posted by
kenandjenn4551
The Idle Torques will solve this. The car likely has a ton of timing movement.... this really needs to be limited to keep the idle relatively stable.
I set my minimum timing values to 2* in the idle cells and my PT timing is 18 degrees. The surging you feel while stopped is the car overcompensating with torque to bring up a idle that is below desired.
I would set your idle at 800-850 initially and play with Drive Proportional Spark to try and calm it down.
In reality, it takes a lot of fine tuning on the Spark and Throttle torque side to get everything to really play nice, but Proportional spark will really make it surge in drive.
Essentially, you want to allow the rpms to fluctuate some, but not to much. My car has about a +/- 50-70 rpms swing from the base of 800.
If it dips to much below 800 rpms, idle torques (both spark and throttle) will kick in and raise the idle.... if to much correction is applied... surge, surge, surge.
Ideally, your timing will only move maybe 10-15 degrees and do so rapidly. On the plus side, this produces a nice cam lope that isn't the "Chop" that everyone has due to huge timing movement.
Send me an IM....I have spent many, many hours working on this area of my tune and it is tough when you first start out.