How to Perform a Motor Swap in Forza Horizon 6

ThunderComet

Swapping engines in Forza Horizon 6 isn’t just a flashy way to boost horsepower—it’s a core part of building a car that fits your driving style. Whether you’re chasing top speed, maximizing cornering performance, or experimenting with unusual builds, knowing how to perform a motor swap safely and efficiently is essential.

Forza Horizon 6 makes this process intuitive but layered, so taking the right steps ensures your car’s Performance Index (PI), weight balance, and handling stay optimized.

Step-by-Step Installation

Enter a Garage

Drive to any unlocked Horizon Festival site or visit one of your player houses across Japan. Any garage with an upgrade shop will do.

Open the Upgrades Menu

From the garage interface, select Upgrades & Tuning. This gives access to all parts, tuning presets, and conversions.

Select Custom Upgrade

Choose Custom Upgrade to see the full parts layout. This lets you pick and preview modifications before committing.

Navigate to Conversions

Scroll to the far right to find the Conversions tab. Here, you’ll find engine swaps, drivetrain conversions, and more.

Select Engine Swap

Click Engine Swap to see all compatible motors for your current vehicle. Preview each engine’s horsepower, weight, and PI impact.

Buy and Install

Highlight the engine you want, then confirm your purchase. The swap is applied instantly, and your car’s stats update in real-time.

Key Upgrade Mechanics in Forza Horizon 6

Motorcycle Swaps for Kei Cars: For the first time, high-revving motorcycle engines like the 1.4L Hayabusa I4 or the 1.0L CBR1000RR-R Fireblade I4 can be installed in subcompact Kei vehicles. This unlocks surprising speed and agility for lightweight cars.

Engine-Specific Aspiration: Some engines restrict what turbo or supercharger options are available. For instance, large V8s may only allow Twin Turbos or Positive-Displacement Superchargers, so check the Aspiration Conversions after selecting a motor.

Power-to-Weight Ratio Matters: The standard V8 swaps from previous games have been rebalanced. Always check the Power-to-Weight Ratio (PWR) when swapping to avoid hurting handling or wasting PI points. A heavier engine can make your car faster in a straight line but tricky to corner.

Performance Index Adjustments: Every swap affects your car’s PI. Higher PI can limit your matchmaking in multiplayer events, so weigh power gains against event eligibility.

Tips for a Successful Swap

Test each build in a free-play session before entering competitive events.

Combine swaps with drivetrain conversions (FWD/AWD/RWD) for optimal handling.

Keep an eye on wheel and suspension upgrades—engine power alone doesn’t guarantee a better lap time.

Experiment with unusual engine choices for fun “quirky” builds; Forza Horizon 6 rewards creativity.