FH6 Circuit Tuning Guide

Circuit is the default racing discipline in Forza Horizon 6 and the baseline every other tune deviates from. The goal is repeatable grip: a car that takes the same line lap after lap, communicates before it slides, and uses all of its tire on smooth tarmac. Here's how each system contributes.

Tires: pressure by compound and weight

Race-oriented compounds want 31.5–32.5 PSI (sport 31.5, semi-slick 32.0, slick 32.5), with the baseline shifted by car weight — a 2,200 lb car sits at the baseline, a 3,000+ lb car needs roughly a pound more, a featherweight needs less. Drivetrain sets the front/rear split: RWD carries about +0.75 PSI in front, FWD +1.5 (those front tires do everything), AWD nearly even.

Springs: stiff, scaled to your class

Circuit springs sit at the top of your car's slider range — for a Sports-class car that's about 98% front / 80% rear of the range, with High Performance and Race Car classes slightly different. Stiff springs speed up weight transfer and keep the platform stable for aero. The calculator then shifts 15 lb/in per 1% of front-weight distribution away from 50/50 — the heavier end always carries the stiffer spring — and scales gently with total weight.

Ride height: as low as it goes

Minimum at both ends. Every millimeter of ride height is center-of-gravity height, and smooth circuits don't demand travel. (If a specific track's curbs upset the car, raise it a notch rather than softening everything else.)

Anti-roll bars: the balance lever

Baselines by drivetrain — RWD 22/30, AWD 26/33, FWD 12/32 — scaled by your car's weight and class, then shifted by weight distribution. ARBs are also your fastest fix afterwards: understeer wants a softer front or stiffer rear bar; oversteer the opposite. The calculator's balance toggle applies exactly that ±2 nudge.

Damping: the 60% rule

Front bump stiffness comes from your car's class and front axle load, and rebound = bump ÷ 0.6 — the community-consensus ratio for FH6. The rear dampers offset from the front based on how different your rear springs are. If the car floats over crests, add rebound; if it crashes over bumps, remove bump.

Aero: maximum, balanced 40/60

Circuit is the one discipline where downforce is almost free lap time, so the calculator runs your wings at maximum — but split to hold an aero balance near 0.40–0.43 front. More front than that and the rear gets loose at speed; less and the car washes wide in fast corners. Front-heavy cars bias toward 0.40, rear-heavy toward 0.45.

Differential and brakes

RWD circuit runs 57% accel / 15% decel — enough lock to drive off corners without inside wheelspin, little enough decel to let the car rotate into them. AWD splits it 29/0 front, 60/12 rear with 78% of torque to the rear axle. Brake bias starts at 52% front (RWD), +1.5 for mid/rear engines, pressure 100%.

Gearing: stretched to terminal velocity

Final drive follows the power-scaled consensus formula (4.25 at 400 hp, taller as power climbs), and the top gear is lengthened so your car's redline in top gear meets its actual terminal velocity — no leftover ratio, no hitting the limiter mid-straight.

Your weight, drivetrain, PI class, and slider ranges set the exact numbers: