Final drive changes how much of your engine output goes into acceleration versus how much goes into raw speed at the far end of the strip. Every other tuning decision is easier once you understand that trade.
The trade in plain terms
A shorter final drive multiplies torque. The car leaves harder, reaches each shift point sooner, and runs out of revs earlier. A longer final drive does the opposite: lazier off the line, but still pulling when a shorter setup has nothing left.
The mistake is treating one end as correct. Neither is. The correct setting is the one that has your car crossing the finish line just as it runs out of usable pull, and not a moment earlier.
Finding it without guessing
- Note where your car finishes the race relative to redline in top gear. If it hits the limiter well before the line, the drive is too short.
- If it crosses the line still climbing through the middle of a gear, the drive is too long and you are wasting acceleration you never used.
- Move the slider in small steps and re-run the same race length several times. Small steps matter because the useful window is narrower than the slider suggests.
Race length changes the answer
A quarter-mile setup and a half-mile setup on the same car should not share a final drive. Short races reward the shorter setting because the launch dominates the result. Longer races reward the setting that keeps pulling, because the launch advantage gets diluted by the extra distance.
Interaction with grip
A short final drive asks more of your tyres. If the car spins on launch after you shorten the drive, the tune is not wrong yet — you have simply moved the bottleneck to grip. Fix grip first, then re-test the drive.
What to record
Write down the setting, the race length, and the finishing behaviour, not just the time. A time on its own does not tell future-you why the setting was chosen.
Related CSR2MODX reading: CSR2 tuning hub · Best cars · Car database
- tuning
- final-drive
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