Corner Weights & Ride Frequency
Set the car up on scales, find the wedge, and speak the same language suspension engineers use: ride frequency. Convert your spring rate and motion ratio into what the wheel actually sees — and pick spring rates for a target frequency.
Corner weights (car on scales, driver in seat)
Total weight
1,396 kg
Front / rear
53 / 47%
Left %
50.3%
Cross weight (wedge)
50%
Cross = (RF + LR) / total. Road racing wants 49.5–50.5%; ovals run it 50–55% to help turn-in. Adjust at the spring perches — every change moves load diagonally, so re-scale after each tweak, and set front/rear % with ride height BEFORE chasing cross.
Ride frequency & spring rate
Front axle
Current frequency
2.07 Hz
Spring for target
7.5 kg/mm
Rear axle
Current frequency
2.14 Hz
Spring for target
6.4 kg/mm
Current balance: rear/front frequency ratio 1.03 (aim ~1.1–1.3 for a well-behaved car). Bands: comfort 1.0–1.4 Hz · fast road 1.4–1.8 · track 1.8–2.4 · slick-tyre race 2.4–3.5+. Motion ratio squared is the trap: a 0.95 MR strut turns a 10 kg/mm spring into ~9 kg/mm at the wheel, while a 0.6 MR pushrod loses nearly two-thirds of it.
Good to know
- Cross weight (wedge) = (RF + LR) ÷ total, scaled with the driver in the seat and tyre pressures set. Road racing wants ~50%; ovals run it high on purpose.
- Wheel rate = spring rate × motion ratio². A 0.95 MR strut loses almost nothing; a 0.6 MR pushrod loses two-thirds of the spring you bought.
- Frequency bands: comfort 1.0–1.4 Hz · fast road 1.4–1.8 · track 1.8–2.4 · slicks and aero 2.4–3.5+. Rear is usually 10–30% higher than front.
- Corner adjustments move load diagonally — re-scale after every change, and set front/rear percentage (ride height) before chasing cross weight.