With the right lug nut and torque how is bending a stud possible?
We run 100lb/ft on 1/2". My sons car leaves pretty hard for its weight (now 1.36 60ft @3775lbs). Also radials are very stiff, not forgiving like a slick. I think the main reason the studs bent was the wheels were stock style steel. The reason? Studs don't drive the wheel. Clamp load between the wheel and rotor/drum drives the wheel. The stock style wheel doesn't have a lot of contact area to the drum/rotor surface due to its design. We corrected this by welding a flat steel plate to the inner mounting face of the wheel. Now the surface area of the wheel is the same as the rotor. For extra measure the studs were upgraded to 5/8" at the same time.
Do the math on the surface area. Not enough contact between the rotor and wheel. Think of it as a small brake rotor vs a larger one, more surface area, more grip. They definitely bent. I've seen other cars do it also. For what its worth the same car has sheared a 8 3/4 pinion in half and torn the ears right off a Dyno-Tech aftermarket drive shaft. Radials in a hard leaving car that is heavy are pretty brutal. These failure occurred when we tried to leave on 20psi, didn't like it. Leaving at 14psi it has been 1.36/9.55@142 3770lbs with a 3.55 gear
Let me try one more time to explain. The stock wheel has less than 50% contact with the rotor surface by design. It doesn't have a large flat surface like an aluminum aftermarket wheel. The wheel is driven by the clamp load between the rotor and wheel, not by the studs. If the clamp load isn't sufficient the wheel will slip on the rotor. Even at 100lb/ft with the proper lug nuts the clamp load was insufficient. The wheels slipped against the rotors bending all 10 studs (aftermarket 1/2" x 2" Moroso). Trust me we were surprised until talking to other people who had seen the same issue. Using simple basic physics we came up with a solution. No trouble since. How many heavy mid 9 second cars run stock steel wheels? Try it yourself and see.
