The original final drive ratios for the Q50 & Q60's R190 differential top out at only 3.133:1 (and that's on the Red Sport!), which is fine for a commuter car with the 7-speed automatic, but less ideal for aggressive competition use, or those with transmission/motor swaps. We chose a 50 tooth ring gear and a 14 tooth pinion which equates to a 3.571:1 ratio for the final drive.

We originally designed this for use in our Q60 Red Sport Manual Conversion, so we chose a ratio that better aligns with both the 6-speed MT's ratios, as well as the power output of the car, but it can benefit factory automatic cars, in the right application.



Switching to a higher final drive ratio will increase the vehicle's nominal RPM (that is, it will increase the engine speed across the board, for any given vehicle speed), which will also reduce the vehicle's overall top speed. The trade-off is that a higher final drive ratio will dramatically improve torque to the wheels, providing faster acceleration, making it especially ideal for a car that sees track duty or competition use.

The ring and pinion blanks are forged from 20CrMnTi-- a chromium, manganese, titanium, and steel alloy, which is then machined to final dimensions, and finally heat-treated for uniform strength. They are designed to meet or exceed OEM quality, fit, and finish.

Professional Installation Recommended!

How to properly break-in a new gear set: Keep RPMs low and drive easy avoiding highways if possible for the first 20 or so miles, then stop and let the differential and drivetrain cool. Repeat this step four or five more times, being sure to allow the gears to fully cool between each trip while also avoiding jerky acceleration or high RPMs during this period. After 100 to 150 miles of easy driving, you can start to enjoy the full RPM range, but still be sure to avoid jerky accelerations or fast gear changes when possible for the first 500 miles. At or very soon after 500 miles, change the gear oil in the diff and check the old fluid for metal shavings or other debris to make sure there are no abnormal signs or wear. If all is good, you're ready to rip!