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CorteX Racing ARP Wheel Stud kit for S550

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tim said:
All the broken studs we are seeing are with closed lug nuts. A customer just sheared 3 off the rear of the car drving down the highway. Factory studs, torqued, aftermarket wheels(TSW) which required tiny lug nuts to fit into the wheel holes. Care needs to be taken with closed lug nuts. Looks should always be the last consideration. If the stud is shearing off in the lug nut area the cap of the nut was likely bottoming out and you are getting a false torque. The wheel is not clamped but the stud has been what amounts to being twisted off...think of trying to remove a rusted nut from a bolt, you twist the bolt to the shear point. The wheel not being clamped in place is now flexing at the same point you just overloaded the stud at. Fortunatley the stud fails somewhat in the wheel hole so the wheel hopefully stays attached to the car.

Stay safe my friends!

I thought I posted earlier on this, Tim is exactly correct, many (most) sanctioning bodies won't allow closed lug nuts for 2 reasons, #! they want to see the depth of the threads into the nut and #2 the closed nuts, even if only a few thousandths of an inch off, will not properly clamp the wheel and cause a stress moment on the stud. Closed nuts might be OK for the street but are bad juju for anything track related.
 
In conclusion; aftermarket wheels designed for the S197 such as Forgestar can be ised on the S550 without risks of breaking studs?
Given the nuts are open ended and torqued properly.
The issue about the lack of precision in the bolt circle of the wheel and its bolt bore size resulting in side loading the studs is not an issue or is not a verified fact?
I am asking because I have two sets of brand new 19x11 that should have the right offset for the GT350...
 
In the TSW scenrio the hub centric rings caused the issue (obvious thing but I wasn't there) causing a false clamp load that overtime caused the wheel to flex the studs to failure. The reasoning behind the previous posts about wheel bolt circle is trying to determine what other causes have the same effect, side loading a stud due to misalignment was considered.

In the end if it has a spec for the S197 it will likely not cause an issue. Plastic centering rings that don't fit on the otherhand....
 

TMSBOSS

Spending my pension on car parts and track fees.
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Exp. Type
HPDE
Exp. Level
10-20 Years
Illinois
In the end if it has a spec for the S197 it will likely not cause an issue. Plastic centering rings that don't fit on the otherhand....
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Plastic Centering rings which do fit often fail when exposed to the heat of track use. Go with Aluminum and ensure they do not bind.
 

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