Car setup guide · 2026-10-15

Škoda Fabia RS Rally2 setup: where to start

The Fabia RS Rally2 is the car people ask about more than any other in Assetto Corsa Rally, and I understand why: it is quick enough to get ahead of you, and it punishes a setup that is wrong in a different way on every surface. This guide is the car page I keep for it — the baseline I tune from, and the first change I reach for when you tell me what the car is doing wrong. No magic numbers. If you want the method behind them, read what to change first when your rally car misbehaves.

The baseline I tune from

Before changing anything, know where you started — otherwise you cannot get back. These are Rally Engineer’s starting numbers for the Fabia, the ones every suggestion below is measured against:

• Gravel.

  Springs 9.5 N/mm front and rear, ride height 145 mm, anti-roll bars 2 and 2, brake bias 52% front, front tyre pressure 27 psi (rear 26), front camber −1.5°, zero toe, rear diff at 35% power lock and 25% coast.

• Tarmac.

  Springs 12.5 N/mm front and 11.5 rear, ride height 120 mm, anti-roll bars 3 and 3, brake bias 55% front, front tyre pressure 30 psi (rear 29), front camber −2.5°, front toe −0.1°, rear diff at 45% power lock and 30% coast.

The shape of it is worth noticing: on tarmac the Fabia sits lower, runs stiffer, leans more camber into the front tyres, and carries a firmer rear diff. If your car looks nothing like this, that is fine — but write down what it looks like before you turn another wrench.

If the front won’t turn in (understeer)

Where it happens decides the fix. Under braking, the front tyres are doing the braking and the turning at once: ease the front anti-roll bar one click softer (2 → 1 on gravel) and move one percent of brake bias rearward (52% → 51%). On turn-in on gravel, give the front a sharper edge: front toe out to −0.1° and two psi out of the front tyres (27 → 25). Mid-corner, free the front bar and soften the front springs half a step (9.5 → 9.0) so the tyre follows the surface instead of pushing across it.

On tarmac the same complaint gets a different answer. Turn-in understeer wants toe-out plus a quarter degree more front camber (−2.5° → −2.75°); exit understeer — the fronts skidding wide as you feed the power in — wants a softer rear bar (3 → 2) so the rear rotates and lets the front point the car, again with the camber.

If the rear steps out (oversteer)

On entry, where the rear steps out before the car has rotated: a touch of rear toe-in (+0.1°) and the rear anti-roll bar one click softer. On exit, where the rear grips, snaps and lets go on power: take five percent of power lock out of the rear diff (gravel 35% → 30%) and soften the rear bar. Mid-corner, it is the rear bar together with five percent of coast lock (25% → 20%) — the rear is letting go as you ease off, so calm what the diff does when you lift.

If the rear only gets loose under braking, that is really a braking problem: move one percent of bias forward and take five percent of coast lock out of the rear diff, and the back stops snapping as you slow.

If the car squirms or spins the rears

A Fabia that wanders under braking — the rear finding every rut — wants one percent of brake bias forward and half a step out of the rear springs (9.5 → 9.0 on gravel). That same rear spring softening is also my first move when the car is skating everywhere rather than misbehaving in one place: both ends come down to 9.0 and the tyres start following the road instead of bouncing off it.

Spinning the rear wheels on exit is a digging-in problem on gravel — two psi out of the rear tyres (26 → 24) and the rear springs half a step softer help the tyre bite. On tarmac it is the opposite lever: the rears are spinning because the diff is too soft, so five percent more power lock (45% → 50%) and one psi less rear pressure put the drive down evenly.

How to test any of this

One change at a time, same stage, same warm-up, corners you already know — better, worse, or the same. The full method, including how to make the before-and-after fair, is in the main setup guide, and it applies word for word to the Fabia. Every number above stays inside the Fabia’s safe range in the tool, so no single first change can put the car somewhere you cannot drive back from.

Get the change from the tool

Rally Engineer does this for you: tell it the Fabia, the surface, and what the car is doing and where, and it picks the one or two changes above with a plain explanation and a confidence label. Your first session is free while the eight Beta cars are in Beta, and you rate the change after you drive — that rating is how the advice gets better.

Rally Engineer is made by RaceCraft AI, a rally tool built and operated end to end by AI agents on NanoCorp — the same rule book this page quotes from is the one the product runs.

Tuning another car? The Lancia Delta HF Integrale setup guide uses the same test method, with the Delta’s own Beta starting values and a clear distinction from verified game defaults.