It's Finally Available! The 981 GT4/Spyder Shorter Final Drive Ratio
10-10-2017, 03:16 PM
#31
Race Director
AQM 981 Shorter Final Drive Ratio
The Issue
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.
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. Our new shorter final drive ratio is now perfectly suited for track use, and much more exciting for street driving. It is much more responsive, feeling similar to having an additional 50hp at your disposal.
Comparison Chart
Installation
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.
Fitment
981 Cayman S/GTS/GT4
981 Boxster S/GTS Spyder
981 Boxster S/GTS Spyder
Price:
$2598 (new crown ring and pinion only)
***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 for Mobile Viewers
John Gaydos
Cell: 484 883 6197 (text available)
Work: 239 432 1700 (John, Gavin or Amy)
Email: john@autoquestms.com
Cell: 484 883 6197 (text available)
Work: 239 432 1700 (John, Gavin or Amy)
Email: john@autoquestms.com
10-11-2017, 04:14 PM
#33
Former Vendor
Thread Starter
10-12-2017, 12:16 AM
#35
So rev match works as it's supposed to? Confused as I thought rev match was software based like it knows what gear you are trying to put it in and then revs to the proper rpms, if that's the case there's no way it can know what rpm you are supposed to be in.
Maybe I have the inner functions all wrong? But doesn't make sense that the car can know and adjust for the shorter final drive. Unless you fix it through tuning of a Cobb?
Maybe I have the inner functions all wrong? But doesn't make sense that the car can know and adjust for the shorter final drive. Unless you fix it through tuning of a Cobb?
10-12-2017, 02:05 AM
#36
GT3 player par excellence
Lifetime Rennlist
Member
Lifetime Rennlist
Member
^ i dont know how it konws, but if ypou change gear ratio, the rev match still works, i know b/c i changed gears 3-6 and it's fine.
however if you put aftermkt shocks, the rev match wil no longer work. we did this to 3 cars, all same result.
however if you put aftermkt shocks, the rev match wil no longer work. we did this to 3 cars, all same result.
10-12-2017, 09:46 AM
#37
How odd. Wonder why changing shocks would affect rev matching.
10-12-2017, 12:01 PM
#39
Former Vendor
Thread Starter
We are doing those calculations shortly. The new 6th is about the same as the factory 5th, so drive around a bit in 5th and you'll have a pretty darn good idea. That being said, we've just arranged the ability to put in a longer 6th, which combined with the FD will put the new 6th within 200rpm as it was from factory 
We had conversation with Porsche about this topic. The rev match feature is controlled by the DME based off the RPMs. Gearing has no play in the functionality of this feature, nor have we seen any change in it's accuracy from any of the 3-5 gear changes some our our clients are running.
Witchcraft! I have Gavin making a few calls on that to ease my curiosity haha
So rev match works as it's supposed to? Confused as I thought rev match was software based like it knows what gear you are trying to put it in and then revs to the proper rpms, if that's the case there's no way it can know what rpm you are supposed to be in.
Maybe I have the inner functions all wrong? But doesn't make sense that the car can know and adjust for the shorter final drive. Unless you fix it through tuning of a Cobb?
Maybe I have the inner functions all wrong? But doesn't make sense that the car can know and adjust for the shorter final drive. Unless you fix it through tuning of a Cobb?
Witchcraft! I have Gavin making a few calls on that to ease my curiosity haha
Last edited by AutoQuest Motorsports; 10-15-2017 at 08:20 PM.
10-12-2017, 12:05 PM
#40
Former Vendor
Thread Starter
John, curious if this mod (or even any power mod for that matter) is automatically 'reflected' in the hp/tq charts from our digital instrument cluster. I don't know if they are dynamic or just statically programmed in.
Meaning, if you add 25hp does the 'dyno' graph move up to show the increase?
If you change the gear rations (or final drive) would the plots change?
Meaning, if you add 25hp does the 'dyno' graph move up to show the increase?
If you change the gear rations (or final drive) would the plots change?
I'll keep my eyes out to confirm as we get some more GT4's through the shop this season.
10-12-2017, 12:35 PM
#41
Former Vendor
Thread Starter
I'm not typically one to compare against another company's products. What I will say is simply factual and logical based on the data, and that is our final drive reduction is more aggressive than that of any of the individual gearing solutions. This means more acceleration/thrust. We are going to release some graphs today/tomorrow to show you exactly where you are getting the improvements in the various gears. We are also doing a thrust comparison to the 997.2 GT3RS and the results so far have been quite interesting...
10-12-2017, 12:54 PM
#42
Former Vendor
Thread Starter
Last edited by AutoQuest Motorsports; 10-12-2017 at 06:52 PM.
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HawkerDriver (08-15-2019)
10-12-2017, 01:08 PM
#44
Former Vendor
Thread Starter
That's Mike Rockenfeller for you haha. Gavin is in the 2:07s with his 997 GT3 Cup, it's pretty ridiculous. I was at Sebring last weekend riding shotgun in a 997.2 GTB1 Cayman S on Pirelli slicks running 2:31s, and that felt fast haha.
10-12-2017, 01:19 PM
#45
Former Vendor
Thread Starter
