GT4 Shorter Final Drive Ratio

AQM 981 Shorter Final Drive Ratio

The Issue
One of the most common complaints about the GT4 has been the long gearing. This is especially prevalent on the track where it takes a good bit of time to rev through the powercurve, and you’d be hard pressed to find a track anywhere in the world where you’d ever use 6th gear. The factory final drive ratio has a top speed equivalent of 201mph, which sacrifices the intensity of the acceleration curve and leaves us with a GT4 that is not nearly as quick or responsive as it could be on track and not as exciting as we’d like on the street.
Our Solution

We have spent over 18 months researching and developing a new crown ring and pinion to shorten the final drive ratio. Our new ratio is 19% shorter, reducing the final drive from 3.89 to 4.62. The new gear ratios are now perfectly suited for track use, and much more exciting for street driving. The new shorter final drive ratio is much more responsive, feeling similar to having an additional 50hp at your disposal.

Comparison Chart


Replacing and setting up a crown ring and pinion correctly can be a challenging task and requires specialized experience. To maintain our 12 month product warranty, we have made arrangements with one of the leading Porsche Transmission Specialists in the US, BMC & G in Ohio, to perform the installation and assist in the shipping of your transmission.

  • 981 Cayman S/GTS/GT4
  • 981 Boxster S/GTS Spyder

$2598 (new crown ring and pinion only)

Reinforced 3rd gear and longer 6th gear available per request

***We are now taking $1000 deposits for November delivery***

Placing an Order

While we are not yet set up for E-Commerce we will efficiency take your order via our contact information below. We would also love to take the time to learn a bit more about you, the goals you have, and offer our recommendations to meet them and maximize your driving experience. With few exceptions, as long as we aren't on track or taking a nap we are available : ) Shoot us a call, text or email 24/7!

Contact Information

John Gaydos
Cell: 484 883 6197 (text available)
Work: 239 432 1700 (John, Gavin or Amy)