949racing 6UL 4th Generation Wheels With V8 Roadsters Brake Kit Clearance

Published: October 20, 2015

I just received a set of new, fourth generation 6UL wheels and tracked them on my Miata with V8 Roadsters front brake setup (11.75" front rotors, Wilwood Dynalite calipers).

Surprisingly, fourth generation 6ULs have less clearance than the first and second generation wheels (I have not had a third generation wheel). The fourth generation wheels rub on the calipers:

Left side caliper after one session:

Right side caliper:

Damage to the wheel:

It is interesting to note that the wheel was contacting the caliper for about half of the circumference. The impact area ended very distinctly:

This suggests that hub centering rings on wheels may not be a terrible idea in track use - the chassis bouncing up and down like that cannot be good for wheel bearing life.