new 997 turbo uses the 964 C4-type of power distribution
03-17-2006, 12:01 AM
#1
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new 997 turbo uses the 964 C4-type of power distribution
I found it interesting that the brand new 997 turbo does not do its 4wd torque distribution via a viscous clutch like prior models, but instead uses a multi-disc clutch similar to that in our 964 G64 transmission. The 997T uses an electronic controller to vary the torque, versus the 964's hydraulic method to control the clutch packs...
I think it's pretty interesting... thought I'd share with my fellow 964 enthusiasts for whatever reason! I try to tell my wife these things, but I get no excitement!
I think it's pretty interesting... thought I'd share with my fellow 964 enthusiasts for whatever reason! I try to tell my wife these things, but I get no excitement!
03-17-2006, 09:30 AM
#2
Burning Brakes
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I'd be curious to know Porsche's reasoning to revert back to a 964 design. Must have had issues with their viscous clutch and a good service record with the 964 design. Nice to know that few of the 964 designs are still worth duplicating 10 plus years later. Maybe Porsche really did spend more quality engineering on designing the 964 versus their transition to the 996 and 7 models.
03-17-2006, 09:52 AM
#3
Marc Shaw posted an interesting dicussion here on viscous couplings which highlights some of the pros an cons of that system as apposed to that used on the 964.
It is interesting that Porsche would go back to a technology more akin to the 964's, which, as has been pointed out, is over 10 years old.
It's always nice to hear that the old thing you have is better than the new thing that has replaced it along the way.
Cheers,
Dave
It is interesting that Porsche would go back to a technology more akin to the 964's, which, as has been pointed out, is over 10 years old.
It's always nice to hear that the old thing you have is better than the new thing that has replaced it along the way.
Cheers,
Dave
03-17-2006, 06:35 PM
#4
Originally Posted by last toy
I'd be curious to know Porsche's reasoning to revert back to a 964 design. Must have had issues with their viscous clutch and a good service record with the 964 design. Nice to know that few of the 964 designs are still worth duplicating 10 plus years later. Maybe Porsche really did spend more quality engineering on designing the 964 versus their transition to the 996 and 7 models.
03-18-2006, 10:01 AM
#5
Three Wheelin'
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From what I read in Excellence looks like the 997TT has the 959 4wd system.
A controlled clutch pack using front -rear wheel speeds to send drive to the front with no epicyclic gearbox to do the basic torque split.That will mean that with it turned off the car is RWD . Be good to see more on that system - can it be made to fit a 964????????????
The viscous coupling is a cheap and cheerful method for 4wd .Problems with it are that front drive is dependent on front - rear wheel diameters ratio and the temperature of the viscous fluid etc etc.
Somewhere I have a Porsche book, where from memory, they say that Porsche would never use a viscous coupling because of its drawbacks! Guess the 90s accountants won that battle!
Just my $0.02
Geoff
A controlled clutch pack using front -rear wheel speeds to send drive to the front with no epicyclic gearbox to do the basic torque split.That will mean that with it turned off the car is RWD . Be good to see more on that system - can it be made to fit a 964????????????
The viscous coupling is a cheap and cheerful method for 4wd .Problems with it are that front drive is dependent on front - rear wheel diameters ratio and the temperature of the viscous fluid etc etc.
Somewhere I have a Porsche book, where from memory, they say that Porsche would never use a viscous coupling because of its drawbacks! Guess the 90s accountants won that battle!
Just my $0.02
Geoff
