What snap oversteer actually is
Ordinary oversteer builds; snap oversteer arrives. The rear axle goes from gripping to sliding in a fraction of a second, usually because a tyre or the platform was already on the edge and one input — a lift, a stab of throttle, a kerb — tips it over. The danger isn’t the angle, it’s the lack of warning: by the time you feel it, the catch is already late.
The progressive version — see oversteer, the rear that steps out gradually.
How the engineers diagnose it
Snap oversteer is almost always a transient — the engineers find the exact instant and the input that triggered it:
- Lift-off vs power-on — a snap when you lift is weight transferring off the rear (engine braking plus a tight coast diff); a snap on throttle is the power diff or too little rear grip. The throttle trace at the moment of the snap says which.
- Platform or kerb — if it snaps over a kerb or a crest, the rear is running out of travel (too stiff, too low, harsh fast-bump) and momentarily unloads. Look at ride height and rear damper fast-bump.
- Thermal edge — a rear that snaps only late in a stint is thermal: the rear tyres are over their window. That’s pressures and load, not the diff.
The cure is rarely «more rear grip» everywhere — it’s removing the trigger and restoring warning. One change, three laps, read corner by corner. See the glossary and the setup guide.
The levers that cure snap oversteer
From the trigger outward — the differential and rear dampers first, platform and thermals next: