The 997TT (including both first and second generation) PTM consists of an electronically controlled center differential lock, which acticely controls torque distribution. The PTM control unit under the rear seat shelf evaluates wheel speeds independently lateral and longitudinal acceleration in relationship to steering angle. It works in conjunction with the optional rear differential lock.

If you note the video from Porsche's microsite that Chad posted here http://www.porsche.com/microsite/tec...PMT911TurboAll, the car modeled is the original 997TT, not the updated version.

If I am not mistaken, PTM with an electrically controlled multiclutch setup is a recent upgrade to the MK2 Carrera 4 and 4S.

I do not know enough about the new 997TT MK2, but my understanding is the electronically controlled center differential lock is similar, with a few changes, and is available with a vectoring system which is a software-based system that uses active differentials to shuffle power from one rear wheel to the other. I believe it replaces the optional rear differential lock from the previous 997TT.

 

I actually started to look at this after looking at Switzer's times and the hp coming from stock internal motor's without bending the rods.

There isn't a significant difference in the 997 motors versus the 996tt motors. The rods look to be the same. Sure there were small differences with the motors, however nothing to account for what is going on. There are 996tt motors producing many times the power of the Switzer cars but their times were not as good.

People with 996tt's were biting, hooking up and bending rods. I believe the difference is the Porsche Traction System on the 997tt. This system in milliseconds transfers power and it is capable of transferring 100% of the power fore or aft. This system is faster in the straights and the twisties than an equal powered 996tt with it's vicious coupling transfer system. It also prevents rods from bending (due to the way it transfers power) at the current power levels being utilized with the current 997tt motors.

I may be wrong, however I don't believe so. I believe the Porsche Traction System makes a hugh difference. It's something that needs our attention.

 

Having owned both cars, there is an obvious difference in the 997TT versus the 996TT...the differential provides a significantly greater RWD-like experience under WOT until you slip.

 

I think there are much easier ways to get the handling of a 996 TT as good or better than a 997 TT. That swap seems like it would be PITB once you add in all the programming that would be needed. And that's IF (a big IF) the parts are a direct swap and don't need modification.


CJV I doubt the PTM has much to do with a 60-130 run difference.

 

I don't know .......... do you or are you guessing?

I don't believe the parts will be cheap. From the pics I have seen of the diff/clutch it is installable. I am currently looking at the sensor issues.

 

I know for a fact there are much easier ways to get the handling better than trying to swap out a whole traction management system.

I do not know if the parts swap or not. The 997 TT has more power, a stiffer chassis, better stock supension and bigger contact patches on the tires. All of that is easy to address.

 

It makes sense. Also, as was pointed out, new for the 997.2 is PTV which could make another improvment in putting power down in a curve.

 

What do you base your opinion on. The 996tt viscous coupling isn't capable of transfering 50 foot pounds of torque to the front. The PTS is capable of transfering 80 to 100% of the torque.

Is it your opinion the rear wheel slippage lost on the 996tt doesn't amount to much?

 

Chad the part you showed here correlates with part number:

997 349 020 50 front-axle final drive ready for installation

It retails for $4448.00 ...

 

What you say doesn't jibe with 6speeds top quarter and other times. The 997tt gives up almost 300 hp to the 996tt's. Furthermore these 996tt's like mine have stiffer frames, superior suspensions. There is only so much contact patch these cars can run. Furthermore, factor in camber and the bigger tires really don't have that much more (if any more) rubber to the road.

 

Appreciate the info. If I can make it work I intend to get one for KA. I'm using a lower front crossmember so this will be interesting.

I going to have to talk to Cary Elsinlohr of ERP and find out what he may know.

 

Here's the part sheet:

Not sure about the computer/electronics

 

Again, thanks for the information.

 

How do you have a stiffer frame?

You are jumping back and forth, are we talking about drag racing or handling? My response was to handling. As far as launching, the 996 TT sucks at that and I think that's a forgone conclusion.

 

Sounds an awful lot like what the Skyline GT-Rs have had for awhile. Managing this with standalone electronics might not be much fun however the ReaceLogic guys have already got a good bit of this sorted IMO. Biggest difference here is that instead of dumping injector pulses a box would need to modify signals to various clutch packs. http://www.racelogic.co.uk/?show=Tra...ustable_System