A fast Forza Horizon 6 tune starts before the tuning menu. Bad upgrades create slow cars. Good upgrades give you PI-efficient grip, power, and control. For competitive S1 road racing, we want one thing: a car that rotates, exits hard, and stays stable when the lobby gets messy.

This guide uses an S1 Lamborghini Huracán AWD build as the reference, but the logic works for most fast road cars.

• Best Forza Horizon 6 Upgrade Order for S1 Road Racing
• Best Conversions: Engine, Aspiration, Drivetrain, Body Kit
• Engine Swap: Use the Most Efficient PI Option
• Aspiration: Centrifugal Supercharger Wins Often
• Drivetrain: Keep AWD on Native AWD Cars
• Body Kit: Use It If It Adds Tire or Aero Value
• Best Tires and Wheels for S1 Builds
• Rally Tires Are the S1 Meta Pick
• Tire Width: Max Rear First
• Drivetrain Upgrades: Differential First
• Best Differential by Car Type
• Transmission, Clutch, Driveline
• Suspension and Handling Upgrades
• Springs: Race or Off-Road
• Anti-Roll Bars: Always Install
• Roll Cage: Usually Skip
• Weight Reduction: Race If Possible
• Engine Upgrade Priority
• Full S1 Lamborghini Huracán Upgrade Template
• Forza Horizon 6 Tuning Settings for S1 AWD Road Racing
• Tire Pressure
• Gearing
• Alignment
• Anti-Roll Bars
• Springs and Ride Height
• Dampers
• Aero
• Brakes
• Differential
• Quick Fix Table: Solve Handling Problems Fast
• FAQ
• What are the best upgrades for S1 road racing in Forza Horizon 6?
• Are rally tires good for road racing?
• Is AWD better than RWD in Forza Horizon 6?
• How do I fix AWD understeer?
• What are good differential settings for AWD S1 cars?
• Summary

↖ Best Forza Horizon 6 Upgrade Order for S1 Road Racing

Do not build around the 1–10 stat bars. They are too vague.

Watch these instead:

The build order that works:

1. Conversions

2. Tires

3. Aero

4. Differential

5. Suspension

6. Weight reduction

7. Power upgrades

8. Final PI cleanup

Build grip and control first. Add power last.

↖ Best Conversions: Engine, Aspiration, Drivetrain, Body Kit

Conversions decide the car's ceiling. Get this wrong and tuning will only hide the damage.

↖ Engine Swap: Use the Most Efficient PI Option

For the Lamborghini Huracán S1, the stock V10 is usually the smart play.

The reason is simple: S1 has limited PI. A huge engine can force you to cut grip, weight reduction, or aero. That usually loses races.

↖ Aspiration: Centrifugal Supercharger Wins Often

For competitive road builds, aspiration efficiency matters more than peak horsepower.

For the Huracán V10, centrifugal supercharger is the go-to. It gives strong high-RPM power without wrecking the PI budget.

↖ Drivetrain: Keep AWD on Native AWD Cars

For online S1 racing, AWD is consistency.

AWD gives:

• Better launch
• Easier corner exits
• Better low-speed acceleration
• Safer recovery on grass
• More stability in traffic

RWD can be faster on clean laps. But it needs throttle discipline. In dirty online races, AWD saves runs.

For the Huracán, keep AWD. Swapping native AWD to RWD is usually a bad trade.

↖ Body Kit: Use It If It Adds Tire or Aero Value

Body kits are not just cosmetic. A good widebody can unlock wider rear tires, aero options, and sometimes weight savings.

If the kit gives wider tires or lower weight, use it. Ugly but fast still wins.

↖ Best Tires and Wheels for S1 Builds

Tire compound is one of the biggest PI decisions in Forza Horizon 6 tuning.

↖ Rally Tires Are the S1 Meta Pick

For S1 all-round road racing, rally tires are often better than the menu suggests.

Why rally tires work:

• Strong grip for the PI cost
• Better grass recovery
• More PI left for power
• Often better lateral G than expected

Do not trust the red/green menu change blindly. Check lateral G.

↖ Tire Width: Max Rear First

Rear tire width is usually worth it. Front width is situational.

For AWD cars, wider rear tires help you run more rear diff bias without losing traction.

↖ Drivetrain Upgrades: Differential First

A serious tune needs a tunable differential. No debate.

↖ Best Differential by Car Type

For the Huracán: Race differential.

↖ Transmission, Clutch, Driveline

Use race transmission if gear spacing matters. Use sport if you only need final drive.

↖ Suspension and Handling Upgrades

Handling parts unlock the settings that actually fix the car.

↖ Springs: Race or Off-Road

For stiff supercars, off-road springs can be better than race springs. They give more compliance and softer ranges.

For the Huracán, use off-road springs. It calms the car and keeps grip over rough sections.

↖ Anti-Roll Bars: Always Install

Install front and rear race anti-roll bars.

They cost almost nothing and control mid-corner balance.

↖ Roll Cage: Usually Skip

Use roll cage only on older cars that need stiffness. On modern supercars, it usually adds weight and wastes PI.

↖ Weight Reduction: Race If Possible

Race weight reduction is one of the best upgrades in the game.

It improves:

• Acceleration
• Braking
• Turn-in
• Tire load
• Direction changes

If you can afford it, install it.

↖ Engine Upgrade Priority

Power comes after grip.

Best engine upgrade order:

For the Huracán S1 build:

• Keep stock V10
• Add centrifugal supercharger
• Add race exhaust
• Add small fillers like intake/ignition
• Use driveline or wheels to land on S1 800

↖ Full S1 Lamborghini Huracán Upgrade Template

Result: stable AWD grip, strong exits, usable top speed, and enough rotation to fight understeer.

↖ Forza Horizon 6 Tuning Settings for S1 AWD Road Racing

These are strong starting values. Test, then adjust one system at a time.

↖ Tire Pressure

For rally tires, start here:

Typical range:

• 1.5–1.8 bar
• 21–26 PSI

If tires overheat, raise pressure.

If the car lacks grip, lower pressure slightly.

↖ Gearing

Goal: keep the engine in its powerband.

For the Huracán V10, power is strong near high RPM. Do not make gears too long.

Use this method:

1. Shorten final drive until acceleration feels sharp.

2. Make sure top gear does not hit limiter too early.

3. Lengthen first gear if launch instantly redlines.

4. Adjust after changing aero.

Shorter final drive = faster acceleration.

Longer final drive = more top speed.

↖ Alignment

Use toe only as a final fix.

If the car still understeers, add 0.1–0.2 front toe out.

If the rear feels nervous, add slight rear toe in.

↖ Anti-Roll Bars

For AWD cars, fight understeer with a soft front and stiff rear.

If it oversteers, reduce rear ARB or raise front ARB.

If it understeers, stiffen rear or soften front.

↖ Springs and Ride Height

For rear-heavy AWD cars, rear springs should usually be stiffer.

Ride height approach:

If the car becomes unstable at high speed, raise rear ride height or add rear aero.

↖ Dampers

Fix springs first. Use dampers for refinement.

If the car bounces, lower bump.

If it floats, raise rebound.

If rear snaps on throttle, soften rear damping.

↖ Aero

More rear aero = safer but slower.

Less rear aero = faster but looser.

For S1 AWD, max front aero helps turn-in. Rear aero should be just enough to stop high-speed oversteer.

↖ Brakes

If the car refuses to rotate while braking, move bias slightly more aggressive.

If the rear steps out, move it safer.

↖ Differential

For a grippy AWD road build:

High accel lock gives strong exits. Low decel helps rotation.

If exits are too wild, reduce center balance or acceleration lock.

If the car feels dead, push more rear bias.

↖ Quick Fix Table: Solve Handling Problems Fast

Always identify where the problem happens: entry, mid-corner, exit, or straight. Then change the matching system.

↖ FAQ

↖ What are the best upgrades for S1 road racing in Forza Horizon 6?

Start with rally tires, race weight reduction, adjustable aero, race differential, race ARBs, and proper suspension. Add power after the car can handle it.

↖ Are rally tires good for road racing?

Yes. For S1 all-round builds, rally tires are often the best PI value. They give strong grip, save PI, and help when you touch grass or rough edges.

↖ Is AWD better than RWD in Forza Horizon 6?

For online racing, AWD is usually better for consistency. RWD can set faster clean laps, but AWD launches harder, exits safer, and survives contact better.

↖ How do I fix AWD understeer?

Use stiffer rear ARB, more rear diff bias, max front aero, and slight front toe out. Do not jump straight to wider front tires unless tuning cannot fix it.

↖ What are good differential settings for AWD S1 cars?

Start with 100% front accel, 100% rear accel, 0% front decel, 5% rear decel, and 75–85% rear center balance. For the Huracán, 84% rear works well.

↖ Summary

The best Forza Horizon 6 S1 tune is not the one with the most horsepower. It is the one that spends PI where it matters.

Use rally tires, race weight reduction, adjustable aero, race diff, race ARBs, and off-road or race springs depending on stiffness. For the Huracán, the winning setup is stock V10, centrifugal supercharger, AWD, max rear tires, off-road springs, and a rear-biased diff.

Build grip first. Add power second. Tune by symptoms. That is how we get a car that turns, launches, and wins.