KartDen

If you only plot RPM, GPS Speed, throttle, and brake, you are still guessing. These two Race Studio 3 math channels turn those traces into grip used and slip generated. Copy each block into Math Channels → New. Set Interpolation, Function, units, and decimals exactly as written. If RS3 throws a nonsense parse error, delete the formula box and type it by hand. Forum paste loves hidden characters, and RS3 hates them. Kart assumed: CKNA-legal LO206, Masters 375, Birel AM29, stock carb/coil, centrifugal clutch. Prefer Rear Axle Speed / Wheel Speed over GPS Speed for anything drivetrain. GPS is the ground-speed reference. 1) GPS G Sum — how close am I to the tire? Combined lat + long G. High mid-corner G-Sum with a clean exit usually means the chassis is working. Low G-Sum with lots of steering means you are asking for grip you are not using. NAME: GPS G Sum INTERPOLATION: Linear Interpolation DESCRIPTION: Combined lateral and longitudinal acceleration. Estimates total tire load usage and how close the kart is to the grip limit. Uses GPS Acc channels. If your logger has a calibrated IMU, swap in AccelerometerY and AccelerometerX. FORMULA: SQRT(POW("GPS LatAcc"[g],2)+POW("GPS LonAcc"[g],2)) FUNCTION: Acceleration OUTPUT UNIT: g DISPLAY UNIT: g DECIMAL FIGURES: 2 Validate: overlay GPS G Sum with GPS LatAcc, GPS LonAcc, Throttle, and Brake. G-Sum should peak in the corner, dip on coast, and climb again on exit as long-G goes positive. If it looks like noise, check GPS Nsat / PosAccuracy before blaming the formula. Starting point on dry LO206: treat about 1.3–1.8 g combined as “working the tire,” then calibrate off your own best laps. 2) Tire Slip Ratio — is the rear driving or spinning? Rear axle vs GPS ground speed, as percent. Positive slip on exit = the clutch/tire is making the kart go. Too much slip = you are polishing the rear. Negative slip under brake = lock or GPS lag. Division is gated at 10 mph so pit-lane zeros do not explode the channel. NAME: Tire Slip Ratio INTERPOLATION: Linear Interpolation DESCRIPTION: Rear axle slip vs GPS ground speed as percent. Positive = driven-wheel overspeed (drive/spin). Negative = axle slower than GPS (lock, coast drag, or GPS lag). 10 mph gate prevents zero-speed blowups. If Rear Axle Speed is missing, use Wheel Speed and note the fallback. Do not fake this channel off GPS Speed alone. FORMULA: ("GPS Speed"[mph] > 10) * (("Rear Axle Speed"[mph] / "GPS Speed"[mph]) - 1) * 100 FUNCTION: Slippage Percent OUTPUT UNIT: % DISPLAY UNIT: % DECIMAL FIGURES: 1 Validate: graph Tire Slip Ratio + Rear Axle Speed + GPS Speed + RPM + Throttle. A good LO206 exit is a short, controlled positive spike as the clutch hooks, then slip settling as RPM climbs through the usable curve toward the 6150 limiter. A long 8–15% slip plateau on throttle is usually the driver over-asking the rear, not “more power.” One view that makes both channels earn their keep Top: GPS Speed + Rear Axle Speed Mid: Throttle + Brake Bottom: GPS G Sum + Tire Slip Ratio Cursor: RPM (watch 4000 vs the 6150 ceiling — above that you are on the limiter and making nothing useful) That answers two questions in one screenshot: did I use the tire, and did I drive it or spin it? Thresholds are start values. Open a known good lap, screenshot the traces, and tune until the channels match what the kart actually did.