I'm working on the tune of a 2016 Camaro SS with full bolt ons and a fairly large camshaft. We've made good power on the dyno, the car starts good, idles right on the desired idle rpm and overall drives great. I worked on the driver demand tables and was able to get the throttle to stay open at wot no problem and worked on the torque coefficient tables to get the car to idle like it should....
The one issue I have, is there is some timing retard upon take-off just under normal driving conditions in 1st gear and occasionally it will happen briefly after a shift. With very very light throttle this won't happen, and with an aggressive launch it doesn't seem to happen either. But 90% of the time taking off from a stop as normal it will pull out up to 20 or so degrees of timing for a couple of seconds and then finally the timing jumps to what it should be in the main table and the engine noticeably accelerates. When this happens, 'immediate engine torque source' logs 'Axle'. When the timing kicks in, 'Axle' will change to 'none'. Also, when this is happening immediate torque, predicted torque, and delivered torque are all reading about the same values. When timing kicks in, immediate torque jumps up along with delivered....but predicted stays the same. Depending on how you feather the throttle to get the car rolling, 'immediate engine torque source' might toggle between axle and none a few times. The timing line on the chart looks like complete garbage when just trying to get the car rolling....and while I wasn't logging all of the correct parameters, timing on the baseline logs we did before any mods look just as screwed up.
To be perfectly honest, I don't have much of a clue about how to utilize the Virtual Torque tool.... and I don't have a clue if this has anything to do with my issues. I'm not sure how a person would ever correctly calibrate all of that without spending weeks on it though. I have set up a histogram to log throttle desired airmass vs. actual airmass as error on the axis of the virtual torque tables and it doesn't seem to be far off in the region that im having these issues. I'm not sure if that's the right way to dial these tables in or not. I have also reduced the torque across the board up to a certain rpm as I would expect to be the case with an aggressive camshaft compared to stock and haven't seen any difference in my issue.
Also, I 'zeroed' out the camshaft timing everywhere except at the very top of the wot region and removed the huge block of camshaft retard that is present in the stock tune so the cam isn't moving around during this issue. Camshaft spark timing is zeroed out as well. The driver demand table is still stock at the throttle positions this all happens. Injector data is all stock and I have the fuel trims basically perfect where this is happening both with the maf and with the vve. This issue happens whether running just MAF, or running in Speed Density.
Any advice would be appreciated. Thanks