New Centerlock Specs/Torque For Track Use. **Read This**
#31
Rennlist Member
the CL is a fk'g disaster.
I did not mind them at all, except for the extra expense of tools and aftermarket wheels.
If I can torque and break 500, I can do 600.
The screw-on thing helps putting the heavy OEM wheels (64lb) on without bouncing of the caliper rotors.
I quickly replaced 4 wheels by myself Sunday, I don't think it takes me any longer than 5 lugs.
But now that the wheels have to be in the air, it's getting to be a pain but I guess we can get one of those brake sticks (Thanks Carrera GT)
On the other hand, what is the reason for the updated instructions?
Some of us have been torqing at 500nm with the car sitting on the floor, not paying any attention to grease and I have not yet heard of any CL flying off at the track, or any other failure to CL or Bolt.
So far, so good?!
#32
Another thought....maybe they are originally torqued to 444 at the factory when the wheels are put on the car...BUT then Porsche tries to make a more reasonable torque spec, and it bites them in the rear ?
Maybe 444 was the number all along.
Maybe 444 was the number all along.
#33
Question...
Why would you have to have the car in the air to torque the wheels, provided that you had somebody or a large dumbbell, or that steering wheel brake thingie ?
Can't you torque the wheels with the brakes on while the car is on the ground ?
Will torqueing the wheels to 444 ft lbs.....could it possibly damage the ceter lock ?
So 349 ft lbs is ok for the street and not the track ? (how about autocross...where speeds are below 85mph and generally much slower.
What if I don't use grease ? Will the wheels fall apart ?
I bet they had a situation where the wheels weren't properly torqued in a race type setting and they came off.
So 444 for the track, but at 349 for street...it's ok if the wheels come off the car ? WTF ?
Why would you have to have the car in the air to torque the wheels, provided that you had somebody or a large dumbbell, or that steering wheel brake thingie ?
Can't you torque the wheels with the brakes on while the car is on the ground ?
Will torqueing the wheels to 444 ft lbs.....could it possibly damage the ceter lock ?
So 349 ft lbs is ok for the street and not the track ? (how about autocross...where speeds are below 85mph and generally much slower.
What if I don't use grease ? Will the wheels fall apart ?
I bet they had a situation where the wheels weren't properly torqued in a race type setting and they came off.
So 444 for the track, but at 349 for street...it's ok if the wheels come off the car ? WTF ?
The distinction is "race" so I think Mr Porsche is identifying any situation outside what would possibly constitute a liability (where an auto maker would be required to furnish a remedy at their cost.)
The grease appears to be a maintenance process when the nut is disassembled for service.
I think the real audience for this service bulletin is the people willing to be cavalier about those new fangled centerlocks as if they were the same old manual system. I've seen cars where the dust caps are left off. I doubt everyone conscientiously "exercises" the spline mechanism and ensures it's engaged. It seems to me that Porsche is simply distancing themselves from negligence that leads to a weakness in their product design.
I doubt a customer has had a wheel escape, but I could imagine there might have been claims on damage if a wheel became loose and the subsequent damage lead to a costly replacement of the hub parts.
The square drive they mention is probably a 3/8th's socket drive. A good question. The fact that they don't have a special tool or a specific tool to manage the process makes it clear this is a situation being "handled" by a few individuals out of their depth and rushing their move. Can that win a game of chess? Well, sometimes, but, can it be the correct process for Porsche?
Is a Web forum how you want to find out that you've been driving at 130 mph with wheels the manufacturer has been unsure about and researching improvements and new procedures to address a potentially fatal flaw?
Is Porsche learning more from Toyota than production line efficiency more than might be best for the customer?
#34
Three Wheelin'
i don't want to be a ***** that complain about everything. i certainly love the CL look. but, i weighted the CL conversion kit recently. it's about 38lbs total. can anyone tell me is it actually heavier or lighter than the old school 5 lugs??
#36
Rennlist Member
Maybe its not so much about losing a wheel but rather seized centrelocks??? It would explain the requirement for copious amounts of grease which originally wasn't required and the added tension may be to compensate for the added lubrication or slippage that the grease will bring... If you think about it, the suggestion is for track use... huge brake temperatures, different metals for hubs/centrelock bolts etc etc... maybe they've had tracked cars seize their centrelocks???? I'm sure we would have seen GT3s with stray wheels on wrecked exotics otherwise.... Just an alternate theory for why...
As for the torquing the wheels whilst the car is in the air, it was easy enough but it does require a second person because you have the added problem of the front wheels wanting to turn left or right so you need the steering wheel held... Changed wheels and torqued with the car in the air during the week and it was fine but only because dad was little helper, chillaxing in the drivers seat holding the steering wheel and stomping the brakes... Better start buying the wives some flowers for a favour gents!!!....
As for the torquing the wheels whilst the car is in the air, it was easy enough but it does require a second person because you have the added problem of the front wheels wanting to turn left or right so you need the steering wheel held... Changed wheels and torqued with the car in the air during the week and it was fine but only because dad was little helper, chillaxing in the drivers seat holding the steering wheel and stomping the brakes... Better start buying the wives some flowers for a favour gents!!!....
Last edited by 911rox; 09-17-2010 at 11:05 AM.
#37
Rennlist Member
oh, i had my 5yr old son hold the wheel and and brake pedal for me the first time i removed the front wheels. his first time helping his dad work on the car. he was soo into it! that was the most fun part
i like the centerlocks a lot actually. i think it actually was quicker than the 5 lugs already, but that was before this announcement. still would like to get justification for the wheel being in the air to torque it all the way down. i always hand tighten while in the air. using my knees to force it on the hub. then drop until the wheel is touching, torque down with torque wrench until its noticeably tight, then drop the car all the way and finish. can't imagine there being any problems with that method.
#38
Rennlist Member
Torquing wheels on the ground
A few years ago, a guy in the shop made the mistake of torquing his CL wheels (with slicks) on his Cup car on the ground. He ended up having to replace all his wheel bearings.
While the cups all have air jacks, torquing the wheels is a two person job - one on the brakes, and one on the wrench - all done with the car off the ground.
PLEASE SEE LATER POST WITH UPDATED INFORMATION...... SORRY!!
While the cups all have air jacks, torquing the wheels is a two person job - one on the brakes, and one on the wrench - all done with the car off the ground.
PLEASE SEE LATER POST WITH UPDATED INFORMATION...... SORRY!!
Last edited by thusly; 09-17-2010 at 05:19 PM.
#39
GT3 player par excellence
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group buy air jack ;-)
#40
Still plays with cars.
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Am I the only one having a problem downloading those pdfs? I get timeouts for some reason. FWIW at the track this week, a 2009 GT3 with centerlocks went home on a flatbed because the hub cracked. Not the wheel, the carrier hub. Interesting.
#41
Burning Brakes
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Loads fine for me.
#42
#44
IB Staff
I just downloaded the PDFs lickety split as well, Bob.
#45
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Gotta love the marketing arm of Porsrsche:
A completely new feature of the 911 GT3 is the wheel bolts with center lock system. This technology, which has been adapted from motor racing, features a high-quality anodized central bolt and stands out clearly from the rest of the wheel.
Hmmm. Can't use power tools. No tools supplied. A complete PIA. But they did supply Locaters for the 5 lug wheels?
A completely new feature of the 911 GT3 is the wheel bolts with center lock system. This technology, which has been adapted from motor racing, features a high-quality anodized central bolt and stands out clearly from the rest of the wheel.
Hmmm. Can't use power tools. No tools supplied. A complete PIA. But they did supply Locaters for the 5 lug wheels?