I currently own a 996 Turbo and I am seriously contemplating adding a 997.1 Turbo next year to my garage. I have no plans to sell the 996 Turbo. Auto Journalists and Technicians appeared to have stated in magazines that the 997.1 Turbo was vastly superior in speed and handling over the 996 Turbo. However, my guess is that most of these individuals probably never OWNED and DROVE these cars on a regular basis. For those of you 997 Turbo owners that have also owned a 996 Turbo, what were the fundamental improvements ( or flaws) that you observed when comparing both vehicles ?

 

I went from a Ruf 550 996 to a 997.2. I think the biggest thing for me was just newer technology like navigation and front body aesthetics. I am not sure the handling is that much better.

 

What about acceleration ?

 

The 997TT has better breathing factory heads and cams, better fuel system, and lower compression (9.0:1 vs 9.4:1)...with exact same modifications, a 997TT will produce more power than the 996TT.

Stock to stock, (even with x50) the 997TT is faster.

Same modifications to both engines, the 997TT will also be faster.

There is a big difference in the handling and balance of the 997TT. The 997TT uses a newer electronically controlled center differential lock, which actively controls torque distribution. The PTM control unit calculates wheel speeds independently of lateral and longitudinal acceleration in relationship to steering angle and works with the optional rear differential lock.

The multi clutch center differential opens and closes in just 100 milliseconds to shunt power between front and rear axles as required to maintain optimum traction. This clutch also opens instantly to free the axles under ABS activation. How does this help?

In comparison to the older viscous coupling system on the 996TT, the 997TT multi plate clutch is capable of transfering 80 to 100% of the torque instantaneously from rear to front. This allows delivery of as much as 100% drive power to be transferred to either axle during slip...(although on a dry road under constant throttle, it send 60 percent of the power to the rear axle.) The 996tt viscous coupling (like the 993) is limited in the amount of torque it can transfer to the front...I've read as little as 50 foot pounds of torque is transferred to the front.

 

^^^Good reading!
I am very surprised at the 60% figure for dry road, constant throttle. That's a lot of power being sent to the front. This is for 997 Turbo right?

 

I was kind of surprised as well, but that's what I thought I read in my service info book on the 997TT, Chad's KA thread, and a few Porsche history books.

My understanding is that the the AWD system used in the 964 had a multi plate clutch. The differential normally sent 31% to the front axle and 69% to the rear. The rear differential also incorporated a similar clutch acting as a limited slip differential. The clutch was controlled by the computer and ABS sensors for each individual wheel. It was criticized as being over-corrective of the tail-happy 911, creating understeer.

Then Porsche changed it's design radically, and moved to a viscous coupling LSD. To make the viscous coupling system engaged in the front, Porsche made the rear wheel/tire diameter smaller, causing a small speed difference between the drive shafts in the front and rear. The viscous liquid normally transferred 5-15% torque to the front axle (which was much less than the 964.) If conditions were necessary, the viscous coupling LSD could send 100% torque to the other axle.

I think the 996 and 993 AWD viscous coupling designs are very similar, and a limited amount of torque can be transferred to the front.

With the 997, Porsche came full circle back to what is essentially a multi plate design.

 

My 996 was modified and a 997.2 is quite a bit faster then a 997.1, so I can't give an accurate measure. I would think a 997 is much quicker then a 996 though.

 

Excellent summary, thank you.

 

Its absolutely amazing how Porsche apparently continues to improve the Turbo. When the turbos get going on my 996 Turbo, it is mind-blowing to me. My guess is you will probably never go back to a 996 Turbo after experiencing the power gains on the 997 Turbo....

 

A 997.2 is quite a bit faster than a 997.1? 6-spd to 6-spd or are you talking vs the PDK transmission? Otherwise, I thought it was only 20hp/tq difference btwn the two??

 

When comapred to a 07-09 997TT, a 6speed 997.2TT traps about 5 mph faster, and half a second quicker in a quarter mile drag race.

http://www.youtube.com/watch?v=5Qam_...ayer_embedded#!

 

Manual to manual...997,1 Vs 997,2 are close...from standstill to 200km 997,2 is faster...however 997,1 is ahead at 300km...weird eh?

 

For manual transmission cars, there is nearly 0.5 difference in the quarter mile between 997 and 997.2. There is also a 4-5 mph difference in trap speed. I don't think that qualifies as close.

 

Yeap...but why 0-300 is better with the older car?I really cant find a reason for that...

 

I'm not sure I believe that. I know it's been beaten to death on RL and RT, but the fact is the 40+ second runs for both cars were done on completely different days and different tracks.

Every side by side run shows that the new turbo keeps up with the GT2, (which ran a 36 second 0-300 km/h.)