What's the deal with floating rotors? At the track last weekend, somebody mentioned that floating rotors made a noticeable difference in brake performance. I have the TSW MDM kit on my car, which uses a 2-piece 12.2"x0.81" rotor. I'm pretty sure it's a fixed rotor, but would it be possible to convert it to floating? My rotors are almost worn out, so I'm wondering if this is an option. Internet searches didn't yield much info, and I haven't talked to TSW yet. Any thoughts are appreciated.
So what is a Floating Rotor many may ask... Standard brake rotors are cast in a single piece which bolts directly to the wheel or drive plate. If the mounting surface of your wheel or drive plate isn't perfectly flat, you'll get vibration at speed. Floating rotors are typically cast in two pieces - the rotor and the carrier. The carrier is bolted to the wheel and the rotor is attached to the carrier using float buttons. The other method of floating a brake rotor is to have the rotor bolted directly to the wheel itself without a carrier, but the bolts have float buttons built into them. [IMGR]http://www.carbibles.com/images/floatingdiscbutton.jpg[/IMGR]These buttons allow the brake rotor some freedom to move laterally, but restrict the angular and rotational movement as if they were bolted directly to the wheel. This slight lateral motion (which can be less than 0.03mm) is just enough to prevent vibration in the brake system. As the calipers are mounted solidly, any warping or misalignment in the wheel or brake rotor mounting face can be compensated for because the rotor will "float" laterally on the float buttons. This side-to-side vibration is separated from the carrier by the float buttons themselves, so none of the resulting motion is transferred into the suspension or steering. Clever eh? The rendering to the right shows an extreme close-up of the brake disc shown above. I've rendered the components slightly transparent so you can see what's going on. Read more: Car Bibles : The Brake Bible StopTech has a page that shows more images in great detail of the differences. See StopTech : Balanced Brake Upgrades
Since you asked for thoughts and not facts, my thoughts are that if you did find a floating rotor for your MINI, the performance increase would not justify the additional cost.
Hehe, this is the internet, everything's a fact. =) I spoke with a mechanic who time trialed his MINI. He had floating rotors on fixed calipers (I think Werkin MINI sells those rotors). He had been through the same issues as I had, and he said floating rotors were the final step, after fluid, lines, pads, ducts, and fixed calipers, that made the brakes good enough. Anyways, I didn't know if anybody on here had done research on this already. I guess I'll end up doing it the hard way, calling vendors and shops.
Performance Friction's approach http://www.performancefriction.com/images/Trade_Pub_Arts/2003NovCircleTrackDirectDrive_e-Print.pdf The PFC rotor designed for the MINI and its self centering caliper, has a slightly different machanism than the T-Bobbin fastener, although the same principle.
I don't know what kind of brake problems you are having. The MDM kit isn't the best choice for track use. I doubt that just changing to a floating rotor would make things much better. I spend a lot of time on the track and braking isn't ever a problem. I do know a good bit about brakes and in particular, MINI brakes. PM me if you would like to talk specifics. Maybe I can help.