Hi guys,
I'm looking for ceramic rotors for my R53 JCW. Currently I'm running Carbotech AX6s on the front and rear. I'm looking for that for weight reduction.

 

ceramic? you'd be better off with 2pc iron/alloy rotors if you a) want lighter weight and b) drive the car on the street

 

Thanks PGT. Any link for a product or manufacturer?

 

dba rotors from Australia is a good choice (model 5000 is two-piece). or Brembo.

 

Thanks! Any idea about the JCW rotor size? Or Brembo part number? Also any idea about the weight saving?

 

usually, about 2-3lbs is the max (main benefit is thermal capacity....the heat from teh rotor doesn't transfer to the wheels/hubs). No idea if Brembo or dba makes 2pc applications for the JCW kit - probably best to search for '07/R56 app since it uses the same rotor.

 

Man, I did search and found DBA 5000 for the standard Mini but they did not mention the year. For Brembo, I could not locate a 2 piece rotor at all. I thought that the ceramics weight much less than the 2 piece iron/alloy rotors.

Well, if you are recommending the 2 piece for any heat reasons, I'm planning to get Mini Mainia's brake cooling kit.

After fitting my GP wheels and the ability to see how much weight saving enhances driving experience, I'm hunting for a much lighter rotor.

 

Where are you finding ceramic rotors???

 

Still looking! Any idea what is the JCW rotor size? Or the R56 rotor size? This might help

 

I can measure tomorrow. I think you would have to have the new rotors custom made, and it would end up costing way too much to be worth it.

 

OK forget about ceramic rotors. I'm looking for light rotors, regardless what material they are made from.

 

I think you're overestimating the impact that rotor weight reduction will have on performance... with wheels/tires, it makes a huge difference because much the weight you're reducing is out near the rim - reducing the mass of a large diameter flywheel. With rotors, the part you're reducing the weight of is directly bolted to the hub... it definitely can decrease unsprung weight by a few pounds, but won't be anywhere near as impactful as reducing wheel weight.

And, if you look at most of the track junkies, they're ADDING rotor mass... not REDUCING rotor mass (at least at the braking surface - the part the furthest from the hub)... more mass = more brake heat capacity.

And don't expect too much from the ducts. They help - but don't take the place of massive rotors..

 

Wilwood is a great source for lightweight rotors.

http://www.wilwood.com/Centers/Infor...w/mini0205.asp

 

+1 on this. I had 2pc rotors and Brembo's on my Subaru. Switching to one piece dba 4000's....it wasn't really noticeable despite the 3lb diff per corner.

 

Wilwood has no stock replacement rotors that fit the MINI.

While there are some light weight rotors they come only with a complete big brake kit.



If stock light weight rotors are your desire, buy a drilled rotor, cut the stock parts to or below the min thickness, back space the pads if needed, put them on a brake lathe and knife edge the cheek ends, the get out a 1.5" (roughly) hole saw and cut holes in the hat between the studs. If you want to really go nuts drill holes in the perimeter of the vertical surface of the hat section.

 

This kit if from http://www.thebrakeman.com/
http://thebrakeman.com/revolution
"The 12.19 [Revolution] rotor weighs 4.4 pounds, and a 13" ProCast weighs 12.2 pounds. Our convoluted 13" ProCast rotors are also available if you want the look of the Revolution with the better sound-dampening of a cast rotor, they weigh 11 pounds each. The hat itself weighs 1.2 pounds."..... a front + rear kit is a bit over $3,000
the one on the left is the convoluted cast rotor and right is the storm kit's revolution rotor...

please note: I copied most of this info, but I may have messed up somewhere.
also note:"Lightweight rotors are a great idea if they will work for your style of driving and on the tracks you normally race at, however, don't try to use them where they don't belong. Tracks like Martinsville, Gafney, Hagerstown, Walkins Glen and others, were never meant for lightweight rotors. These tracks seriously test brakes and require large rotors to supply the brake system with sufficient resources to remove the heat being generated!"
If I had the $$$$ I definitely wouldn't mind a 4.4lb., 12.19" rotor (I believe the stock rotor is somewhere near 14 lbs.)
I'm not too sure about the heat capacity though.
what's the main reason your're looking to save weight on the brake system??

 

Thanks all. After what I read about rotor mass, I might get the OEM JCW rotors from our local dealer.

 

Rotors are unsprung weight. Saving 1 lb unsprung weight is equilavent to saving 6 lbs of sprung weight. Rotating weight saved; improves acceleration, deceleration, and handling. Additional weight can be saved with the installation of alloy calipers, provided one does not fall into the trap of piston envy.

On the down side, decreased rotor mass decreases the amount of heat that the rotors can adsorb before fade sets in.

Something like the Wilwood rotors save weight by using an aluminum hat with a replacable cast iron or steel rotor. The heat storage capacity of the rotor remains, enhanced by the aluminum hat.

Somethng like the "Revolution" rotor might work as a rear rotor but would lack the heat adsorption capacity to be an effective front rotor during a track event. With all of the cutouts and drillings it might also be difficult to maintain the proper front-to-rear brake bias so necessary during threshold breaking. Playing around with different pad material or installing a brake bias valve, and having someone knowledgeable in brake bias setup, could solve the problem. Probably not an amature weekend project.

 

Thanks Bilbo-Baggins, this is what I had in mind when I first posted in this thread. So the bottom line, where can I get light weight rotors? Do Brembo offer something? I have couple of questions that answering them would really help:

-How much stock JCW rotors or R56 rotors weight?
-What are the JCW rotors or R56 rotors dimensions?

 

While I've heard this MANY times... and I buy it completely for wheel/tire weights, I'd like to see the math to prove that saving a pound on a rotor hat (not disc, but hat) = six pounds of spring weight. I don't think the rotor has a large enough diameter for this to make that much of a difference...

 

sprung weight vs. unsprung weight has to do with any weight below the pivot points of the suspension, not rotating mass. I agree a light rotor won't affect braking or acceleration like wheels do as it's closer to the center of rotation but it does help the suspension react to the road.

 

#1 if you plan on abusing them.

 

Guys, The FMSI part numbers for your front rotor is 120.34092 (F) and 120.34066 (R). That may help them at Brembo or at any other manufacturer to get the right rotors for our R53s.

 

obusing? Can you be more clear please?

 

I understand that part... but 6-to-1? for non-rotating parts... I'd buy 2-to-1, or maybe 3-to-1... I'm just looking to get educated here... if someone can point me to a track test that shows that, with all other things being equal, a car with 20 pounds of dead weight added to the unsprung area went slower than the same car with 120 pounds added in the passenger seat... then I'll be better educated than I was when I started reading this thread. And that would be good.

I'm confident that is NOT the case for drag racing... but would love to see a comparison test on a road couse, where suspension really matters...