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Upgrade reference /drivetrain-conversion

Drivetrain Conversion (FWD ↔ RWD ↔ AWD)

Changes the fundamental character of the car. AWD swap is heavy PI; RWD swap from AWD usually nets nothing.

Your dataCar #3650· last 3 laps
Current drivetrain— (build has no drivetrain set)
Front axle slip avg (throttle > 0.5)15.5%
Rear axle slip avg (throttle > 0.5)25.8%
Rear − Front Δ10.31%

What it does

Drivetrain conversion is one of the biggest single-PI decisions you can make. AWD swap can eat 30–80+ PI on a car that started RWD, in exchange for launch and corner-exit traction. RWD swap from a factory AWD car removes the traction advantage *without* a PI refund — almost always a net loss unless you specifically need RWD for a drift build.

Lock the discipline first, then pick drivetrain. Road racing at A/S1: AWD if the car is heavy or you want forgiveness, RWD if it's light and PI is tight. Drift: RWD only. Drag: depends on launch weight transfer and tire choice. Cross-country and dirt: AWD wins almost always.

FWD is the third option, and it's usually best on the stock factory FWD platforms (small hot-hatches at C/B class). Converting *to* FWD is rare; converting *from* FWD to AWD is common on lighter cars where you want grip without committing to RWD throttle work.

Options

Keep stock drivetrain
PI 0
Best for
Factory AWD cars (GT-R, WRX, Quattro) — already balanced for their power
Tradeoff
Locks you into the factory character
Swap to AWD
PI 30–80
Best for
Cross-country, dirt, snowy/wet weather builds; heavy power builds that can't put power down
Tradeoff
Heavy PI cost; adds weight; reduces top speed
Swap to RWD
PI 0–10 refund (rare)
Best for
Only if going for a drift build or a specific RWD chassis character
Tradeoff
Loses AWD traction without a corresponding PI gain — usually a net loss
Swap to FWD
PI variable
Best for
Extremely rare — almost never the answer
Tradeoff
Adds on-throttle understeer and limits engine swap options

Decision rules

  • 1.Decide discipline before drivetrain. Don't convert to AWD on a drag build that doesn't need it.
  • 2.Light cars at D/C class rarely benefit from AWD swap — the PI cost is too high for the budget.
  • 3.Don't swap to RWD on a factory AWD car unless you specifically want RWD behaviour.

Traps

AWD swap on a 600 kg D-class hatchback
Why  The PI cost eats your entire engine + tire budget and you don't need the traction at D-class power levels
Instead  Keep the factory drivetrain; spend the PI on tires and weight
RWD swap on a factory AWD car for "purity"
Why  No PI refund; you lose launch and exit traction with nothing in exchange
Instead  Keep AWD and tune the center diff if you want more rotation

Build smells that point here

  • AWD swap on a light low-class car
    Revert to factory drivetrain; spend the 30–80 PI on tires and weight.

Related

Engine SwapDrivetrain Parts (Diff / Trans / Driveline / Clutch / Flywheel)