Lug Nuts
10-17-2008, 03:32 PM
#1
Safety Car
Thread Starter
Lug Nuts
As I run around the country I take a lot of pictures of strange things. When I was writing my Wheel and Tire Performance Handbook I took a bunch of wheel and tire pictures.
The shocking thing was how many race cars paid no attention at all to how the wheels were held onto the car. The general rule of thumb is that you should have as much thread showing as is the diameter of the wheel stud. In other words if you have a 12 mm wheel stud then at least 12 mm of stud should stick out past the lug nut.
Take a look at some of the things I found.
Richard Newton
The shocking thing was how many race cars paid no attention at all to how the wheels were held onto the car. The general rule of thumb is that you should have as much thread showing as is the diameter of the wheel stud. In other words if you have a 12 mm wheel stud then at least 12 mm of stud should stick out past the lug nut.
Take a look at some of the things I found.
Richard Newton
10-17-2008, 04:44 PM
#3
Le Mans Master
As I run around the country I take a lot of pictures of strange things. When I was writing my Wheel and Tire Performance Handbook I took a bunch of wheel and tire pictures.
The shocking thing was how many race cars paid no attention at all to how the wheels were held onto the car. The general rule of thumb is that you should have as much thread showing as is the diameter of the wheel stud. In other words if you have a 12 mm wheel stud then at least 12 mm of stud should stick out past the lug nut.
Take a look at some of the things I found.
Richard Newton
The shocking thing was how many race cars paid no attention at all to how the wheels were held onto the car. The general rule of thumb is that you should have as much thread showing as is the diameter of the wheel stud. In other words if you have a 12 mm wheel stud then at least 12 mm of stud should stick out past the lug nut.
Take a look at some of the things I found.
Richard Newton
Good pictures, though, once I got to it.
no pictures
10-17-2008, 07:00 PM
#5
Le Mans Master
10-17-2008, 07:27 PM
#7
Team Owner
As I run around the country I take a lot of pictures of strange things. When I was writing my Wheel and Tire Performance Handbook I took a bunch of wheel and tire pictures.
The shocking thing was how many race cars paid no attention at all to how the wheels were held onto the car. The general rule of thumb is that you should have as much thread showing as is the diameter of the wheel stud. In other words if you have a 12 mm wheel stud then at least 12 mm of stud should stick out past the lug nut.
Take a look at some of the things I found.
Richard Newton
The shocking thing was how many race cars paid no attention at all to how the wheels were held onto the car. The general rule of thumb is that you should have as much thread showing as is the diameter of the wheel stud. In other words if you have a 12 mm wheel stud then at least 12 mm of stud should stick out past the lug nut.
Take a look at some of the things I found.
Richard Newton
why do you need an inch+ extra as shown in the picture? thanks
10-18-2008, 05:57 AM
#8
Drifting
[QUOTE
The shocking thing was how many race cars paid no attention at all to how the wheels were held onto the car. The general rule of thumb is that you should have as much thread showing as is the diameter of the wheel stud. In other words if you have a 12 mm wheel stud then at least 12 mm of stud should stick out past the lug nut.
[/QUOTE]
What is your reference for that rule of thumb?
The shocking thing was how many race cars paid no attention at all to how the wheels were held onto the car. The general rule of thumb is that you should have as much thread showing as is the diameter of the wheel stud. In other words if you have a 12 mm wheel stud then at least 12 mm of stud should stick out past the lug nut.
[/QUOTE]
What is your reference for that rule of thumb?
10-18-2008, 07:34 AM
#9
Safety Car
Thread Starter
Sorry for all the confusion. Here's a good link.
The confusion is because I wasn't very clear. The key term is engaged threads. In other words on the Corvette lets say the wheel stud is 12mm in diameter. That means the lug nut should have 12mm of threads engaged. It doesn't mean that you need 12mm of wheel stud sticking out past the nut.
Longer wheel studs do though make it a lot easier to install the wheel on a race car. That's why the World Challenge race car on my Blog has such long wheel studs. It's just easier to place the wheel on the hub.
The engaged threads recommendation comes from Robert Woods of Wheel Enhancement. He's one of the major wheel gurus of the western world. They specialize in Porsche wheels.
The Southern California Timing Association, which governs the racing at Bonneville, requires at least 5/8 inch of thread engagement. The SCTA also prohibits the use of closed-end lug nuts.
Closed end lug nuts are a really serious problem. We simply don't have a clue about what's going on with closed lug nuts. It's difficult to see how many threads are actually engaged. A worse case scenario is where the wheel stud bottoms out on the inside of the lug nut which would lead you to believe you're tightened the wheel properly.
Even though you tightened the wheel (so you think) the wheel would still be loose on the hub. Most sanctioning bodies simply don't allow this sort of lug nut.
Think about the C4 Corvette for instance. GM used an open end lug nut and then provided a little plastic cover to make the lug nut look good. It would have been a lot easier to just manufacture a closed end lug nut - but they didn't feel it was safe.
Richard Newton
101 Projects for Your Corvette 1984-1996
The confusion is because I wasn't very clear. The key term is engaged threads. In other words on the Corvette lets say the wheel stud is 12mm in diameter. That means the lug nut should have 12mm of threads engaged. It doesn't mean that you need 12mm of wheel stud sticking out past the nut.
Longer wheel studs do though make it a lot easier to install the wheel on a race car. That's why the World Challenge race car on my Blog has such long wheel studs. It's just easier to place the wheel on the hub.
The engaged threads recommendation comes from Robert Woods of Wheel Enhancement. He's one of the major wheel gurus of the western world. They specialize in Porsche wheels.
The Southern California Timing Association, which governs the racing at Bonneville, requires at least 5/8 inch of thread engagement. The SCTA also prohibits the use of closed-end lug nuts.
Closed end lug nuts are a really serious problem. We simply don't have a clue about what's going on with closed lug nuts. It's difficult to see how many threads are actually engaged. A worse case scenario is where the wheel stud bottoms out on the inside of the lug nut which would lead you to believe you're tightened the wheel properly.
Even though you tightened the wheel (so you think) the wheel would still be loose on the hub. Most sanctioning bodies simply don't allow this sort of lug nut.
Think about the C4 Corvette for instance. GM used an open end lug nut and then provided a little plastic cover to make the lug nut look good. It would have been a lot easier to just manufacture a closed end lug nut - but they didn't feel it was safe.
Richard Newton
101 Projects for Your Corvette 1984-1996
Last edited by rfn026; 10-18-2008 at 07:38 AM. Reason: add link
10-18-2008, 03:18 PM
#11
Safety Car
But they feel they're safe now for the C6? Something doesn't smell right.
10-18-2008, 05:40 PM
#12
Tech Contributor
Member Since: Oct 1999
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Bill
10-20-2008, 11:49 AM
#14
Race Director
Sorry for all the confusion. Here's a good link.
Think about the C4 Corvette for instance. GM used an open end lug nut and then provided a little plastic cover to make the lug nut look good. It would have been a lot easier to just manufacture a closed end lug nut - but they didn't feel it was safe.
Richard Newton
101 Projects for Your Corvette 1984-1996
Think about the C4 Corvette for instance. GM used an open end lug nut and then provided a little plastic cover to make the lug nut look good. It would have been a lot easier to just manufacture a closed end lug nut - but they didn't feel it was safe.
Richard Newton
101 Projects for Your Corvette 1984-1996
Interesting thread. I wonder why on my c5z/z16 they went backwards to a closed lug nut.
10-20-2008, 02:04 PM
#15
A closed lug is still perfectly safe with aftermarket studs or wheels if you take the time to do some measuring.
I can't believe you guys are running off to replace your lugs!
10-20-2008, 02:45 PM
#16
Former Vendor
Thanks
Randy
FYI, We sell a bunch of different studs for pretty much every Corvette application
www.dougrippie.com
10-20-2008, 02:53 PM
#17
Drifting
When evaluating hardware I look to ensure hardware provides at least 1.5 thread past nut engagement. I can find the requirement if it is important but that seems to be a basic rule. Be careful on our lug nuts as they are not fully treaded but if you look into an open lug nut you can verify that the stud is long enough for your appliciation.
10-20-2008, 03:08 PM
#18
Melting Slicks
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A closed lug is perfectly safe if OEM wheels are used. I doubt GM is concerned much with liability on aftermarket wheels.
A closed lug is still perfectly safe with aftermarket studs or wheels if you take the time to do some measuring.
I can't believe you guys are running off to replace your lugs!
A closed lug is still perfectly safe with aftermarket studs or wheels if you take the time to do some measuring.
I can't believe you guys are running off to replace your lugs!
An open lug nut allows one to visually inspect that the nut is sufficiently engaged on the thread. Coupled with proper torque, there then is no question that everything is properly in place.
The drawback of a closed nut is that you can't visually determine how the threads are seated. You could even have some "crap" building up in the end of the closed nut that would allow you to acheive proper torque, but without enough threads being engaged. Granted, it might not occur very often, but anything possible will eventually happen.
It's a $20.00 fix that might prevent a catastrophic failure. My safety is worth much more than that.
Feel free to use any nuts you want.
10-20-2008, 05:41 PM
#19
Safety Car
So who has good lugs? I bought some from Summit Racing (12mm x 1.5) that fit fine, but they use a 13/16 socket which nothing else on the car does. I'm looking for some nuts that, at a minimum, use a metric socket... ideally I'd like a 17mm, 18mm or 19mm nut...
10-20-2008, 08:28 PM
#20
Team Owner
I bought some OEM Chevy juts here from a vendor. Local dealer wanted 110 for twenty vendor here was 55
Nuts and studs do wear after constant removal and replacement. Got my longer studs from DRM
