Assetto Corsa EVO: unstable under braking — what to change
What it feels like
Braking hard in a straight line the car moves around, the rear tries to come round or you lock up.
Ready-made AC EVO setups with every value explained — PDF + JSON, one-time payment.
Buy the pack — US$14.99Why it happens and what we're after
Unstable braking: move brake bias forward, add one ABS step and raise diff preload so the rear stays in line under engine braking.
What to change, exactly
Ranges, steps and defaults are the REAL ones for this sim. The amount is expressed in the game's own unit so you can apply it without converting anything.
Parameters flagged as “estimated range” do not come from a verified in-game capture: the direction of the change is right, the exact magnitude may differ on your car.
1.Brake bias (front)
Raise ↑ by 0.6 %3 slider stepsestimated rangeRange: 50.0 – 70.0 % · Default: 60.0 %
Percentage of braking sent to the front axle (in the editor it lives in the Suspension tab as 'front brake distribution'). Higher = more front brake. Key adjustment for corner entry.
What changes when you move it this way
More forward = more stable braking, but more risk of locking the fronts and understeering.
2.ABS
Raise ↑ by 11 slider stepestimated rangeRange: 0 – 11 · Default: 4
How much it prevents wheel lock under braking. Higher = intervenes earlier. Setting it to 0 isn't always faster.
What changes when you move it this way
More ABS = safer braking and fewer flat-spots, especially in the wet; braking distance lengthens slightly.
3.Differential preload
Raise ↑ by 10 Nm2 slider stepsestimated rangeRange: 0 – 300 Nm · Default: 100 Nm
How much the two driven wheels resist turning at different speeds before the LSD acts (in the editor: 'differential preload', in the Suspension tab). Affects how the rear reacts in gentle throttle transitions.
What changes when you move it this way
More preload = more locked, stable behaviour, but less agile on entry (some understeer).
This adjustment does not apply to front-wheel-drive cars (the differential acts on the driven axle).
How to apply it without losing your afternoon
- 01Change ONE thing at a time and run three clean laps before judging. Two changes at once and you no longer know which one worked.
- 02Start with the first parameter on the list: they are in the order the engine applies them, from the one with most authority to the fine tuning.
- 03If the change goes the right way but falls short, repeat the same step again before touching another parameter.
- 04If it gets worse, put it back. A setup you don't understand is slower than a baseline you do.
Where this sim stores its setups
AC EVO (Early Access) saves setups in-game as 'Setup Presets' (create/name/save), under Documents/ACEvo, but as of June 2026 it has no file import/export for setups: copy the values by hand into the in-game editor.
If you'd rather skip the trial and error, the AC EVO pack ships ready-made baselines with every value explained, as PDF and JSON. One-time payment, instant download.
Buy the pack — US$14.99Want the exact values, not just the direction?
The generator takes your car, your track, the weather, grip and fuel, and returns the full setup with the reasoning behind every number. Free to start.
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If that wasn't it
Symptoms get confused with each other: what feels like poor traction is very often oversteer on throttle. These are the other diagnoses for this sim.
- Understeer on corner entryYou turn in and the car keeps going straight: it washes wide before the apex.
- Mid-corner understeerMid-corner, at steady speed, the car refuses to hold the line and you have to unwind the wheel.
- Understeer on corner exitAs you get on the throttle the car pushes wide and runs out of road on exit.
- Oversteer on corner entryAs you release the brake and turn in, the rear steps out and the car rotates too much before the apex.
- Mid-corner oversteerMid-corner the rear keeps sliding on its own and you are correcting with the wheel the whole way through.
- Snap oversteer on throttleYou get on the power on exit and the rear snaps sideways: spin, or a big correction.
- No traction on corner exitOn exit the driven wheels spin and the car won't hook up: you lose time down the next straight.
- Tyres overheatingGrip falls off after two or three laps and temperature or pressure climbs past the window.
- Tyres not coming up to temperatureThe first laps the car slides everywhere and the tyres take forever to switch on.
- Car bottoming outOver fast sections or compressions the floor hits the track, the car bounces and you lose grip exactly there.
- Unstable over kerbsTouch a kerb and the car jumps, gets unsettled, and you end up avoiding kerbs to keep it.
The same problem in other sims
Same symptom, different parameters: each game exposes different sliders, with other units and other ranges.