So for a while now, I have been trying to optimize my VVE tables on my 2.0T LTG with E80A ECM in a '17 ATS.
I am running into a wall when modifying my VVE table. There are so many variations of CAM angles and you can only modify the VVE able at 0* intake and exhaust. However, the input from the logs display VE at multiple CAM angles.
The issue is after about 5 or 6 iterations of adjustments to the VVE table, I start to get a bucking effect between 1500-1800 RPM, once you pass that area in the table its fine. I cant seem to wrap my head around modifying efficiency within the SD VVE tables.
I have the MAF pinpointed and scaled within 1.5 in the LTFT's and the car runs fine in blended tune, its just a tad bit lean when blended as opposed to MAF only. I am hoping someone out there has tackled or mastered these VVE tables on the 2.0T LTG.
Not sure if this is related but when you modify the table are you interpolating sections out beyond where you are actually getting data or are you just paste special multiply by half percentage and then calculating coefficients? If you have large differences between cells you want to make sure you interpolate between actual data and out beyond cells that you hit from actual data. Also' if you have a trouble area you may want to consider changing your zone parameters to make that section smaller.
No your spot on! I have interpolated the sections of data collected and multiplied by half percentages surrounding the data to smooth out transitions. However, with all the CAM angles, there are jumps between some zones that are significantly different (higher or lower) then their correlating sections. I will post a screen shot of what it looks like as soon as I get home today. Thanks for the response.
I think I can kind of see them but can you post a picture of the vve table spreadsheet with show zones selected? Or even better just attach a tune file and scan file. Or check this video out. 14:00 starts discussing what I'm thinking may help. I love this channel, if you haven't checked it out it is great.
I went back to the zones under engine-airflow-dynamic, and adjusted the zones a bit and equaled out the pressure ratio boundary?s. I?m gonna start logging this weekend and see how I fair out. Hopefully I have better luck this go round.
Yeah but soon as I start adjusting and getting some fidelity on the VVE table, the predicted torque numbers go wacky and start closing the throttle body. I can?t figure out how to get that straight