On this M2 spindle topic, there is one thing not yet mentioned, that IMO becomes a shortcoming, and that is the typical wilwood M2 alum hubs. As first noted, a 3000lb+ car on the track, running hot laps, with the related likely brake temps heating the alum hub, is far from ideal, being at 375F? (if I'm reading graph correctly?)6061 has lost nearly half its strength, combined with a non robust bearing already mentioned, ie small outer race diameter, and alum expansion, things cannot be improving. There are of course aftermarket steel hub solutions, but some weight reduction is lost and cost now becomes a factor.
http://www.burnsstainless.com/images/technology/YieldStrength-1.gif Now you're really grasping at straws. First, the bearings are almost identical between the mopar factory bearings and the mustang 2. Second, all of wilwoods kits for mopars use aluminum hubs just like their kits for mustang 2, if there was a heat problem with aluminum hubs, it would affect every wilwood kit regardless of bearings or brand spindles. 3rd, ypu can get steel hubs for the mustang 2 just like you can for mopars. Heck, speedway sells a kit for 200 bucks with hubs, rotors, calibers the works. Granted it's just stock style brakes but those aren't any different than a stock mopar brake kit.
4th:aluminum doesn't hold heat like steel. Aluminum will dissipate heat much quick, so while it does have a lower melting point (1280 degrees for 6061) than steel, it's going to take a lot longer to heat via braking to get to that point. 5th: everyone from nascar to IRL to GT use aluminum hubs. If there was a heat problem with aluminum hubs, we'd know it. 6th: if youre getting your hubs heated to the point of failure, youre gonna melt a bead on the tire long before the hub fails and you probably should adjust your line and driving style. 7th: I just looked up the temp ratings for both the bearings used in stock hubs on stock spindles for both the mustang ii and the mopars, both have a operating temperature of -140 degree C to 1030 degree C, if you can get that bearing to 1030 degrees C, you've got some serious issues, far more than just the type of spindles you're running. That'd be well over 2000 degrees F and close to the melting point of even steel.
This mustang ii heat bs theory is easily debunked with simple research from the makers of the bearings and hubs themselves and some simple common sense and math.
Fyi, I deal strength and load testing every single day for my job. I have to find out the bending and breaking points of all sorts of metals and alloys. It's what keeps the engines of the company I work for together.
Also, one last note. The mustang 2 bearings are actually larger in diameter than the mopar bearings, they are however, slightly thinner in the bearing width, less than a 1/16 of an inch. So if you're gonna say the mustang 2 spindle bearing isn't big enough diameter wise to handle a 3000 lb car, then the mopar bearing isn't either........using your line of thinking
