Have you upped the anti with your 996 TT or 997 TT?

[Hawk2109]

Hey there everyone,

I wanted to let everyone know that if you have increased the HP of your 996 TT or 997 TT, we now have a modification that you really need to take a look at with regard to the cooling of your gearbox.

Many of you may know me from my days at Carquip, I have now changed companies, and now work for Gbox, just down the street.

I have long tried to help as many people as possible on the Pelican site and feel very fortunate to be a part of this community. I look forward to continuing the great relationship into the future with everyone, and am very excited about some of the new services that I get to offer now.

So here is the deal with you current gearbox setup, and what I have to offer.


The 996 TT and 997 TT gearbox does not currently come with the option for a oil cooler and pump, as you would find say the GT3 gearbox. Apparently in Porsche wisdom they did not feel that these cars were going to take the same kind of pounding that the more track dedicated GT3 does, and did not include this on the 4wd gearboxes.

I can take care of that for you now.

So you may be asking yourself, Why would I need that?

Well here is the short answer to that question. Heat KILLS gearboxes, and if you have increased HP to your turbo, you may have noticed that you are now generating more heat as a result. The gearbox is also generating more heat due to the extra work load it has to handle.

Here is the more in depth answer to the what actually takes place for our conversion.

The 996 Twin-Turbo gearbox was designed by Porsche for the stresses of the 400-450 horsepower factory engine and the g-forces generated by the stock chassis. Porsche recognized the limitations of a street gearbox in high-performance applications with the GT3Cup and the RSR. The g-forces that these cars generate, and the high rpm within the gearbox required Porsche to use a pressurized oiling system with external cooling (using a pressure-regulated mechanical pump driven by the pinion shaft). At high rpm, oil is thrown off the gears by centrifugal force, and under hard g-loading oil is forced into the differential housing. Using a pump to scavenge the oil out of the differential housing and a spray-bar to oil the gear-mesh allowed these gearboxes to survive the rigors of racing. When the engine is upgraded the gearbox must be upgraded. With 996TT engines producing 800-1000 hp the stresses on the gearbox exceed stock-design capability. Upgrading the oiling/cooling system and using more robust 997TT parts in the gearbox will allow it to handle the increased horsepower and torque. The GT3Cup/RSR pressurized oiling/cooling system can be fitted to the G96/50 AWD gearbox using Porsche Motorsport Parts.

The steps to install the GT3Cup/RSR oiling system are as follows.

The 'street' bell housing is machined to accept the oiling system parts. New replacement bell housings also must be machined.

Passage machined for oil tube.

Bell housing machined for the piston squiter.

Center section with oil pump provision (p/n 996 310 102 9A).

Mechanical oil pump (with internal pressure regulator) (p/n 996 307 023 88), oil pump pinion drive gear (p/n 964 307 331 01), differential housing scavenge pickup (p/n 996 307 049 9A), spray bar (p/n 996 307 043 88).

Motorsport tail-cover (p/n 996 301 301 9A) which requires additional machining for the 4wd application (bore for output seal and block off pinion oil gallery).

Scavenge pickup installed in the differential housing.

Scavenge pickup mounting hole in billet retainer plate (p/n 996 302 121 9A GB), left.

Oil pump installed in center section. 3/4 shift fork must be machined for oil pump drive clearance.

Spray bar installed.

Oil cooler and tail-cover installed.

This oiling system upgrade can be performed on the G96/50 4wd gearbox, on the G96/90 GT3 gearbox and others, Additional upgrades include limited-slip differential, re-gearing with stronger 997TT mainshaft and up-rated clutch slave cylinder modification..


So I am sure that some of you have some questions about this and that is what I am here to help with.

Please feel free to contact me directly and I will be happy, as always, to discuss this in detail, including pricing.

Warmest Regards, and happy to help,




Erik Johnson
Gbox Sales Manager
(303) 440-8899 work
(303) 895-4525 cell

[Hawk2109]

So I see that there have been people who have viewed and read this, but no one has replied.

I would love to get some opinions on this modification if you have time.

Thanks

Erik