AutoQuest Motorsports

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.
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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.

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!
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Buteo

Would you be able to address the 3rd gear potential failure at the time of final drive install?

noro78

Add this to the single mass light flywheel and you can start taunting 991 GT3s at the track. Love it, plan to get it after I get my GT4!

cox1974

wowwwwwwww

rflavell

What the approximate cost of installation?

AutoQuest Motorsports

After the 1st of the year yes, that is when Guard should have their factory ratio 3rd gear replacement released

When you're ready to get a GT4 let me know, we can get you one of those as well

I'm imagining another one of your 1/4 mile time comparisons

I've spoken with Brian over at BMC&G and installation would cost about $1k. That doesn't include the removal/installation of the transmission by whichever shop pulls the transmission and ships it to them. You're just a hop skip and jump away, perhaps that's something we can chat about. Plus I owe you a follow up on that Multi Link haha

ajw45

This is great! Any chance there's a longer 6th gear being developed as well to keep a decent highway cruising rpm?

AutoQuest Motorsports

Glad you like it : )

I have some inquiries out on the 6th gear, but it's likely not something we are going to push. 6th gear will essentially become the equivalent of the current 5th gear, which isn't unreasonable as it is. Throwing a long 6th gear into the mix would make the 5th to 6th gear shift not a very linear experience. As we have essentially make 6th gear now attainable on some fast tracks here in the states, we wouldn't recommend a taller 6th as you'll lose all your momentum shifting into it. If you don't ever plan on hitting over 139mph at full bore it might be something to consider, but again we haven't found the current 5th to be uninviting at cruising speed

CAlexio

This plus sharkwerks light flywheel. A-mazing work

Everyone should just go out and try to blow up their third gear which will give you a free transmission removal and install by Porsche.. order your sharkwerks flywheel in meantime, then get the work done with the new auto quest pinion.

And while you’re at it get some sport headers on the beast

Needsdecaf

Would love this on my 991 also. Hate the long gearing.

konaforever

Tempting!

jlennox

Can you discuss the pros/cons of a shorter final drive vs Guards 2nd - 5th shortened regearing (assuming the 2nd gear is ever actually released). Other than being potentially cheaper, are there going to be any significant advantages over your solution vs Guards?

DuncGT4

Sounds great and one more mod to add to the list, shorter gearing and a few bolt on engine goodies would be nice once the warranty runs out

cox1974

ciao John... What about the european guys like me? Can we use our dealer or trusted workshop for the installation?

MagicRat

I second ***’s question, and well done John! My shop in London said final drive wouldn’t happen for GT4/Spyder because both first and second were on the input shaft. Not gonna lie I wasn’t completely sure what that meant but it sounded important. Any more details would be appreciated!