XRAY - Model racing cars

Looking for help with a good gearing and rollout setup for my Xray X10 pan car on an indoor medium size high bite carpet track. Currently running avg 12-13 second laps with a pretty solid setup.

I have calculated a few pinion options based on the foams @ 52.5mm and 88 spur with the Team Powers 13.5 motor.
41 Pinion = 77.03 Rollout
39 Pinion = 73.26 Rollout
37 Pinion = 69.55 Rollout
35 Pinion = 65.67 Rollout

1. The larger pinion and more rollout produces more low end punch, correct? (Haven't noticed much power difference here at full timing)

2. Anyone running this same class and type of carpet track with the new 1S Trinity short stack 13.5 motor?

3. Any feedback on other 13.5 motors to be considered for this scenario?

Thanks!