Using Optimum Lap and Mario’s base model I’ve modified to match the PartsBadger Car: https://occamsracers.com/ I’ve run some simulations based on Road America.
These simulations are actual weights and power numbers, but what is important is the delta times with each change.
- Base Lap: 2:33.83 Road America (Kink)
- 148RWHP
- 6850 RPM Max RPM
- 4.3 Diff
- 0.410 Drag
- 1.2 Df Coefficient)
- 4.1 Diff vs. 4.3 Diff = +0.15 seconds slower
- 133rwhp = +2.87 seconds slower
- 136rwhp = +2.22 seconds slower
- 139rwhp = +1.62 seconds slower
- 142rwhp = +1.02 seconds slower
- 145rwhp = +0.47 seconds slower
- 148rwhp = baseline
- 151rwhp = -0.48 seconds faster
- 154rwhp = -0.98 seconds faster
- 157rwhp = -1.38 seconds faster
- 7050rpm vs. 6850rpm = -0.28 seconds faster
- 6585rpm vs. 6850rpm = +0.55 seconds slower
- 2120 = – 0.51 seconds faster
- 2130 = -0.41 seconds faster
- 2140 = -0.30 seconds faster
- 2150 = -0.20 seconds faster
- 2160 = -0.10 seconds faster
- 2170 = baseline (with driver 50% fuel)
- 2180 = +0.11 seconds slower
- 2190 = +0.21 seconds slower
- 2200 = +0.31 seconds slower
- 2210 = +0.41 seconds slower
- 2020 = +0.51 seconds slower
- 0.38 Cd = -0.63 seconds faster
- 0.39 Cd = -0.42 seconds faster
- 0.40 Cd = -0.21 seconds faster
- 0.41 Cd = baseline
- 0.42 Cd = +0.22 seconds slower
- 0.43 Cd = +0.45 seconds slower
- 0.44 Cd = +0.68 seconds slower
You can see what contributes to drag in Mario’s write up here: https://occamsracers.com/2021/02/10/where-drag-comes-from-on-a-miata/
- 6spd Transmission vs. 5spd = -0.34 seconds faster