Centerlock VS. Standard 5 bolt wheels ???
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note, cup car CL is VERY different than our street car CL. now THAT is easy peesy.
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Looks? I'm really not enamored with the look of the CL's at all, not to mention I strongly dislike them from an inconvenience standpoint.
One thing that soured me on the GTS is that most of 'em have been spec'd with CL's.
If I ordered a Turbo S I'd order 5-lug. They can keep their $3800 freebie CL "upgrade". I won't own a street car with CL's.
Nothing like a $3800 PITA.
One thing that soured me on the GTS is that most of 'em have been spec'd with CL's.
If I ordered a Turbo S I'd order 5-lug. They can keep their $3800 freebie CL "upgrade". I won't own a street car with CL's.
Nothing like a $3800 PITA.
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Jason
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Dailydriver
Of course you have to consider the weight of the lug nuts, but you also have to consider the weight of the Centerlock nut. It a wash, or worse.
Unfortunately, the very slight "moment of inertia" advantage you suggest is more than offset by the much higher overall mass of the Centerlock wheel.
Our lightest wheel, the Tech1-110 is a good example. In 19x9 for a new GT3RS, it weighs 7.9 kgs. The same 19x9 in 5 lug weighs less than 7.4 kgs.
So, there is real world 500 gram (1.1 lbs) difference, just due to the Centerlock.
If you study the formula for measuring "moment of inertia" here:http://en.wikipedia.org/wiki/Moment_of_inertia
you will quickly see that increasing the mass by 500 grams will have a huge effect on the kinetic energy required to accelerate the wheel. The small change in MOI, not so much. This is because the energy required to accelerate the wheel increases at the square of the velocity. So, the faster you go, the more lightweight wheels will help you.
I simplified this to make it easy to understand for the non-math majors.
Centerlock wheels look amazing. But they really don't improve performance.
Of course you have to consider the weight of the lug nuts, but you also have to consider the weight of the Centerlock nut. It a wash, or worse.
Unfortunately, the very slight "moment of inertia" advantage you suggest is more than offset by the much higher overall mass of the Centerlock wheel.
Our lightest wheel, the Tech1-110 is a good example. In 19x9 for a new GT3RS, it weighs 7.9 kgs. The same 19x9 in 5 lug weighs less than 7.4 kgs.
So, there is real world 500 gram (1.1 lbs) difference, just due to the Centerlock.
If you study the formula for measuring "moment of inertia" here:http://en.wikipedia.org/wiki/Moment_of_inertia
you will quickly see that increasing the mass by 500 grams will have a huge effect on the kinetic energy required to accelerate the wheel. The small change in MOI, not so much. This is because the energy required to accelerate the wheel increases at the square of the velocity. So, the faster you go, the more lightweight wheels will help you.
I simplified this to make it easy to understand for the non-math majors.
Centerlock wheels look amazing. But they really don't improve performance.
With 5-lug you have to worry about weight of the lugs (which I'll bet are heavier than the CL but by a small margin) as well as torque on each lug being the same. On the CL you just torque it up and forget it.
Also, going over bumps with CL is also more direct and not as sloppy since that nut is aligned along the axis of rotation.
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I'm a big Porsche fan but their center lock is largely a cosmetic device.
Remember that the Porsche center lock wheel is a "pin drive" design incorporating short "lugs" that fit into matching holes in the back of the wheel. This is where the torque transfer takes place.
The lugs are not as long as a standard 5x130 5-lug wheel, but they are there.
The center lock nut is a retention device, pure and simple.
Applying 600 lb ft of torque to this area of the wheel requires a significant increase in mass. It simply is heavier, pure and simple.
There is no legal or scientific definition of the term Driving Dynamics.
It's what they don't say that is telling. They don't say lower mass or lighter, they don't say lower moment of inertia. They devise a new term, Driving Dynamics".
I stand by my analysis of the physics involved.
At the track, center lock wheels make tire changes faster. For street driving, the CL design is a royal PITA. Ask any CL owner who has to deal with them.
In the end, they are called laws of physics for a reason; so that marketing types can't cover them up with BS.
Remember that the Porsche center lock wheel is a "pin drive" design incorporating short "lugs" that fit into matching holes in the back of the wheel. This is where the torque transfer takes place.
The lugs are not as long as a standard 5x130 5-lug wheel, but they are there.
The center lock nut is a retention device, pure and simple.
Applying 600 lb ft of torque to this area of the wheel requires a significant increase in mass. It simply is heavier, pure and simple.
There is no legal or scientific definition of the term Driving Dynamics.
It's what they don't say that is telling. They don't say lower mass or lighter, they don't say lower moment of inertia. They devise a new term, Driving Dynamics".
I stand by my analysis of the physics involved.
At the track, center lock wheels make tire changes faster. For street driving, the CL design is a royal PITA. Ask any CL owner who has to deal with them.
In the end, they are called laws of physics for a reason; so that marketing types can't cover them up with BS.
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I'm not so sure anyone has done a detailed physics based analysis of the two options. Except maybe Porsche. They wouldn't put something on their site that claims improved driving dynamics without testing it or analyzing it. Another example is PDCC...which improves driving dynamics for sure.
With 5-lug you have to worry about weight of the lugs (which I'll bet are heavier than the CL but by a small margin) as well as torque on each lug being the same. On the CL you just torque it up and forget it.
Also, going over bumps with CL is also more direct and not as sloppy since that nut is aligned along the axis of rotation.
I'm a big Porsche fan but their center lock is largely a cosmetic device.
Remember that the Porsche center lock wheel is a "pin drive" design incorporating short "lugs" that fit into matching holes in the back of the wheel. This is where the torque transfer takes place.
The lugs are not as long as a standard 5x130 5-lug wheel, but they are there.
The center lock nut is a retention device, pure and simple.
Applying 600 lb ft of torque to this area of the wheel requires a significant increase in mass. It simply is heavier, pure and simple.
There is no legal or scientific definition of the term Driving Dynamics.
It's what they don't say that is telling. They don't say lower mass or lighter, they don't say lower moment of inertia. They devise a new term, Driving Dynamics".
I stand by my analysis of the physics involved.
At the track, center lock wheels make tire changes faster. For street driving, the CL design is a royal PITA. Ask any CL owner who has to deal with them.
In the end, they are called laws of physics for a reason; so that marketing types can't cover them up with BS.
Remember that the Porsche center lock wheel is a "pin drive" design incorporating short "lugs" that fit into matching holes in the back of the wheel. This is where the torque transfer takes place.
The lugs are not as long as a standard 5x130 5-lug wheel, but they are there.
The center lock nut is a retention device, pure and simple.
Applying 600 lb ft of torque to this area of the wheel requires a significant increase in mass. It simply is heavier, pure and simple.
There is no legal or scientific definition of the term Driving Dynamics.
It's what they don't say that is telling. They don't say lower mass or lighter, they don't say lower moment of inertia. They devise a new term, Driving Dynamics".
I stand by my analysis of the physics involved.
At the track, center lock wheels make tire changes faster. For street driving, the CL design is a royal PITA. Ask any CL owner who has to deal with them.
In the end, they are called laws of physics for a reason; so that marketing types can't cover them up with BS.
Wow, ancient thread revival.
I think the time as shown that apples to apples, CL wheels are going to be heavier than an identical 5 lug wheel for the reasons stated above.
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I'm a big Porsche fan but their center lock is largely a cosmetic device.
Remember that the Porsche center lock wheel is a "pin drive" design incorporating short "lugs" that fit into matching holes in the back of the wheel. This is where the torque transfer takes place.
The lugs are not as long as a standard 5x130 5-lug wheel, but they are there.
The center lock nut is a retention device, pure and simple.
Applying 600 lb ft of torque to this area of the wheel requires a significant increase in mass. It simply is heavier, pure and simple.
There is no legal or scientific definition of the term Driving Dynamics.
It's what they don't say that is telling. They don't say lower mass or lighter, they don't say lower moment of inertia. They devise a new term, Driving Dynamics".
I stand by my analysis of the physics involved.
At the track, center lock wheels make tire changes faster. For street driving, the CL design is a royal PITA. Ask any CL owner who has to deal with them.
In the end, they are called laws of physics for a reason; so that marketing types can't cover them up with BS.
Remember that the Porsche center lock wheel is a "pin drive" design incorporating short "lugs" that fit into matching holes in the back of the wheel. This is where the torque transfer takes place.
The lugs are not as long as a standard 5x130 5-lug wheel, but they are there.
The center lock nut is a retention device, pure and simple.
Applying 600 lb ft of torque to this area of the wheel requires a significant increase in mass. It simply is heavier, pure and simple.
There is no legal or scientific definition of the term Driving Dynamics.
It's what they don't say that is telling. They don't say lower mass or lighter, they don't say lower moment of inertia. They devise a new term, Driving Dynamics".
I stand by my analysis of the physics involved.
At the track, center lock wheels make tire changes faster. For street driving, the CL design is a royal PITA. Ask any CL owner who has to deal with them.
In the end, they are called laws of physics for a reason; so that marketing types can't cover them up with BS.
I have seen those pins on the hub where the CL attaches. Not sure what they're made of, maybe steel. The inside of the CL has all the holes in order to fit onto the pins, so that's a slight mass reduction on the wheel itself, but then you have the CL nut on the outside.
To me it's an interesting problem. I even have talked to a few techs that really don't know the weight difference.
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Good thread gents. I am not surprised that it has been revived as this sounds like a discussion that will continue.
I have a 997.2 that was converted to 5 Lug from CL. One day I will switch it back, but not for a several years for the reasons discussed in this thread. So, here I sit with 2 Sets of OEM wheels, one in 5 lug one in CL, and 3 sets of BBS 2 in 5 lug and 1 in CL. My wife has been "encouraging" me to clean out the garage and to get rid of all the tires and wheels. I guess she will just have to wait a bit longer.
I have a 997.2 that was converted to 5 Lug from CL. One day I will switch it back, but not for a several years for the reasons discussed in this thread. So, here I sit with 2 Sets of OEM wheels, one in 5 lug one in CL, and 3 sets of BBS 2 in 5 lug and 1 in CL. My wife has been "encouraging" me to clean out the garage and to get rid of all the tires and wheels. I guess she will just have to wait a bit longer.
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