ChrisF

...yes, usually as part of a flying rear wheel

911SLOW

franck84 sent us these pics and I have permission to post them.


Another failure at the Nürburgring with his friend's non-RS GT3.
He was luckier as he didn't lose the wheel..

It was again the RR one and the car was running OZ wheels.
Their local Porsche dealer also refused to cover them under warranty.

ChrisF

Any resident engineer types want to take a stab at a post mortem?

911rox

Nope but there are definite signs of wear on rotor hat and dirt all over the secondary lock suggesting no covers are being used. Question is whether that wear on the hat is the result of this failure or the cause due to previous looseness... Leaving dust caps off and leaving such a sensitive system exposed to so much particulate contamination is asking for trouble imo...

Realistically, when people have these sorts of failures and post shots, it would be great if some info was supplied too... Ie. who has been doing wheel changes, procedure followed etc, etc... We all jumped to conclusions, blaming system failure for gt3de's car but he was nice enough to let us know what the underlying cause was, overtightening....

DJN

Over torquing perhaps, .....or the hubs have timed out (to the second!).

paver

The most intriguing thing IMO is why only non RS's?

911rox

May be coincidence... Maybe most RS guys have had a GT3 before, done the tracking thing and know the importance of being precise in preparation for track whereas the non RS cars are more often bought by first timers (like myself), entering the market with no experience and complacency?... Who knows? Doubt its mechanics because the RSs have a more aggressive offset and therefore theoretically should place greater stress and strain on hubs...

paver

Not knowing if it's really a coincidence just adds to the frustration of the whole CL BS.

Wish we had data on track time of the cars that have had failures and info on what tires were being used.

Targa Tim

GT3 came out first, so maybe most of them will have more mileage than RS?

If only the RR hub is trouble, then changing a new one every track season may solve the issue??

My car have only been touched by the Porsche dealer and my tuning shop, but each shop has more than a few technicians that work there. Honestly, I would have never knew whether my wheels have ever being over-torque in their lifetime. There will never be a way to find out, unless the car has only been torqued by one person all along, and this is impossible.

911rox

I hear you paver but I think the greatest factors here are those centred around how and whom is installing these wheels... Savy, Izzone and Trakcar have all done dozens upon dozens of wheel changes, thousands upon thousands of track miles and are using very sticky rubber on aftermarket wheels and not a hint of an issue for any of them...

Porsche used aftermarket wheels with racing slicks, rattled them off and on and completed a 24 hour enduro without a problem...

Those are all examples of extremes of use way beyond what most will likely ever achieve without an issue... Doubt they would continue with the system on the next generation of car if they had concerns about its safety as the cost of the recall would be far greater over two generations of car as opposed to the one generation already in circulation... I think the user or service guy will have played a far bigger role in all these failures we are seeing than the system...

As I've said to date, the only failing from Porsche that I can see is that they chose to introduce a non fool proof system into a market where a greater than usual number of wheel changes are required as a result of how these cars were intended to be used...

911SLOW

Chris I agree, let's hope that Franck will shed some more light into this.

My understanding is that they've asked for an independent expert to examine the two failures. Also Porsche is sending someone from the technical dpt to look into it.

The more details we have the better..

paver

911rox, I think it stands to reason if there are track-driving non-RS owners who don't handle their CL's properly then there must also be track-driving RS owners who don't practice proper CL procedure either. Why haven't we seen those failures.
Just a thought. Hopefully there will be more info soon re: the investigation Slow mentioned.

franck84

Hello,
On all that cases, the cars used Michelin pilot sport cup. It's exact that i don't use to control the exact torque of the wheels after each 20 min sessions, in the perfect specific process of Porsche CL. It's my 6th 911, and i ride more than 20 000 miles on track with all cars... Thé reality is that this GT3 have lost the philosophy of the 911. Go to the track on the road, ride fast, and back on the road. Just control the tires pression, and ride...
If you have to take Porsche staff with you to ride, only to change à wheel, well, so the GT3 is no longer for me with that kind of hub...
Waiting this, one independant expert has seen my car, and concluded that thé cargraphic wheel participate to the hub failure, but not only. The failure existed... And we don't know why. The only thing that is sure for Porsche is that they are not responsible.
On oct, the 18, one expert from Porsche AG Will come.
I expect this to tell you more, but i really want to change for 5 lubs, according to DJN...
Thank you su much at everyone for your precious advices...

medpilot105

Thanks for keeping us informed of your situation, franck84. We hope to hear what Porsche AG says on October 18.

Targa Tim

Thanks franck84 for useful info.
I have not decided myself what to do yet. RS is now hibernating till next spring.
One thing for sure, I will never buy another car with CL.