Forza Horizon 6 Road Racing Tuning

How to build and tune a road racing car in Forza Horizon 6, and the meta cars per class.

Tuning for road racing in Forza Horizon 6 comes down to the upgrade order, spending PI where it counts, and a setup matched to the surface. This guide covers all three, then lists the best road racing cars per class from the Rivals leaderboards.

In FH6, power is the biggest differentiator in road racing. Fill the car with as much horsepower as the PI budget allows, then tune the chassis to control it. You want strong corner exit traction, sharp turn-in, and stable braking. FH6 has more linear steering response and more forgiving braking than previous titles, so builds can be pushed closer to neutral balance. Aero is crucial at higher classes for maintaining grip through fast corners.

Upgrade priority

The general order for a road racing build. Exact picks scale with class and car, but this is the order that matters.

  1. Engine Swap or Power Upgrades Power is the biggest performance differentiator in FH6. More horsepower means faster straights and stronger exits, which add up to bigger lap time gains than any handling upgrade. Fill the car with as much power as the PI budget allows.
  2. Race Transmission (10-Speed) Unlocks individual gear ratio and final drive tuning. A 10-speed keeps the engine in its power band and cuts time lost between shifts, so matched gearing turns your power into lap time. Without it, extra power is wasted bouncing off the limiter or bogging down.
  3. Semi-Slick, Off-Road or Rally Tyres At A class you can afford semi-slick, but the off-road and rally tyre meta is at its strongest here: leaderboard A-class builds run them for the PI saving and give up very little grip.
  4. Race Differential Unlocks acceleration and deceleration lock. Controls how the power reaches the wheels on corner exit. Without it you cannot manage wheelspin or trail braking.
  5. Front Tyre Width Widening the front tyres is one of the cheapest grip upgrades per PI point. More front grip means you can carry speed into corners and use the power earlier on exit.
  6. Race Anti-Roll Bars Unlocks front and rear ARB tuning. The ARB split controls whether the car understeers or oversteers. Use the mechanical balance readout to dial it to 0.60.
  7. Race Suspension Unlocks spring rate, damping, and ride height tuning. Minimum ride height lowers the centre of gravity. Springs calculated from your weight distribution give an accurate front-rear split.
  8. Rear Tyre Width Wider rears improve traction on corner exit, letting you get on the power harder and earlier. Especially important for RWD cars with high power.
  9. Weight Reduction Lighter cars brake later, turn faster, and accelerate harder. Spend remaining PI on weight reduction after power and tyres are sorted.
  10. Race Brakes Unlocks brake balance tuning. Prevents rear lock-up under heavy braking and lets you brake later into corners.

Best value per PI

Spend here first

UpgradeWhy
Centrifugal SuperchargerCurrently the single biggest performance-per-PI item in FH6: it adds huge power for far less PI than it should, almost certainly a bug. If your car can fit one, it is the strongest power upgrade available until it is patched. Expect it to be nerfed in a future update.
Race ExhaustThe best power-per-PI upgrade in the core engine tree. Install this on every build.
Race IntakeSecond best power-per-PI in the engine tree. Pair with Race Intake Manifold to unlock its full gain.
Race IgnitionVery cheap PI for consistent gains across the whole rev range.
Sport or Race FlywheelOften free performance: on many cars the weight saving outweighs the PI cost, so PI stays flat or even drops while throttle response improves. Watch the PI counter when you fit it.
Sport or Race DrivelineTypically 1 to 3 PI for 10 to 25 kg off the rotating drivetrain. One of the quietest bargains in the shop.
Race Transmission (10-Speed)A 10-speed race gearbox keeps the engine in its power band and cuts time lost between shifts. The extra ratios are cheap PI for a real acceleration gain, and let you tune final drive precisely to the track. A meta pick on almost every build.
Front Tyre WidthThe cheapest grip per PI point on tarmac. Often costs less than a compound step for a similar gain in turn-in and braking.
Off-Road or Rally TyresThe current road meta at A class: both give near race-compound braking and cornering for a fraction of the PI, freeing the budget for power. Off-road grips slightly harder; rally holds up better on any tarmac sections. Almost certainly over-performing, so expect a patch, but until then they are the value pick on tarmac.
Weight ReductionThe best PI-to-performance conversion overall: one upgrade improves acceleration, braking, and cornering at the same time.
Lighter RimsReduces unsprung and rotating mass for very little PI. Experiment with rim style and size while watching the PI counter.

Poor value, usually skip

UpgradeWhy
Race DisplacementThe biggest single power gain but also the most PI-expensive, typically 30 to 60 PI. It usually pushes you past your class ceiling for marginal benefit.
Race Pistons and CompressionHigh PI cost and shifts power toward high RPM, making the car peakier to drive.
Positive-Displacement SuperchargerCosts more PI than a comparable turbo for similar output. Only worth it when you specifically need instant low-end torque.
Rally Suspension PartsRally springs and dampers actively hurt tarmac builds. Note this is about suspension, not tyres: rally and off-road rubber are currently legitimate meta picks at lower classes.
Drag Tyres (Outside Drag)The Series 2 patch removed their cornering grip while keeping the PI cost. The old cheap-PI drag tyre exploit no longer works anywhere except the drag strip.

Adjustment tips

Best Road Racing cars by class

Best R class Road Racing cars

The strongest R class road racing picks right now.

Best S2 class Road Racing cars

The strongest S2 class road racing picks right now.

Best S1 class Road Racing cars

The strongest S1 class road racing picks right now.

Best A class Road Racing cars

The strongest A class road racing picks right now.

Best B class Road Racing cars

The strongest B class road racing picks right now.

Best C class Road Racing cars

The strongest C class road racing picks right now.

Build any of these in the tuning calculator, or read the setting guides for the detail behind each number.