Stan is right, they are wide-5 hubs.
http://www.colemanracing.com/Hub-Wide-5-Fr...e-55-P3626.aspxNo, most GT1 and Trans-Am cars run a standard 'grand national' style hub with 5x5 bolt circle and the top guys run center-lock hubs with only 1 big central lugnut.
My car was designed and built to go as fast as possible as inexpensively as possible while still being durable. It is nearly all from the coleman racing catalog which is plain jane circle-track parts. When you knock a corner off a top flight tube-car you've just spend thousands of dollars on control arms and uprights. With my car, you may spend a few hundred. I pay for cost savings in a bit of weight, but it's fine with me.
The Wide-5 hub is indeed big but it is hollow aluminum and very light for what it is. The benefits include very light wheels (no center mass), HUGE bearings that last and last (they are similar to a 3/4 ton truck in size), and they are extremely durable. Big brakes can work, zero-scrub offsets can work, and even I can't crossthread a lugnut on a 1" stud (at least I've not done it yet!!).
The chassis designation from the guy who made the run of frames (some he sold bare, others he made rollers and hung bodies, about 44 chassis in all however the buyer wanted them) was 'SBE' and it was for Simple But Effective. I've got a H#LL of a lot less money in my car than anyone that turns lap times even remotely close to me.
Costas
cars and such...