What does "as-cast construction" mean? A term I've not heard from any of my suppliers. The machining would appear to be necessary to cut the casting down from a larger stock- just at the 11.75 is produced from the 12.2 casting, that's why you don't see the markings on the 12.2 Wilwood part (only the balancing goove somewhere not seen in the picture) but do so on a 11.75. Still a cool part, just not understanding what you're saying here.
I installed an early model R53 JCW sport brake kit on a customer's car today. The caliper with bracket and brake pads weighed 12lbs. The JCW pad carrier is a little larger than the one on the R56, but a ball park estimation based on its weight says the R56 caliper and similar pad carrier should be about 6lbs heavier than a Wilwood DPR caliper with brackets and hardware.
I haven't had the time to throw an out of the ordinary braking test at the PFC Z-rated street pads yet, but here is an early assessment. Keep in mind mechanical changes were made along with the pad swap. Pedal feel is much more refined for street use than the former Ferodo DS2500 pads on early style Power Slot rotors. Feedback on the former set-up felt like Fred putting his foot down on the Flintstones car, all kinds of sensations were transferred through the ball of my foot. There's not the grabby cold bite of stock pads, nor the "when is it going to stop" feeling like EBC Greens, nor the rock hard heal in gravel pedal I had with the Ferodos. The Z pads are a bit deceptive, modulation starts light, then when I begin to apply exponentially greater pedal pressure, it's stopping here and now without fanfare. I feel another round of bleeds will probably change modulation a bit. Rotor, pads, and caliper temperatures as measured with a touch-less IRT, show temps on average only 60F greater on the fronts in normal commute style driving. If I coast without touching the brakes for a couple hundred yards, and come to a stop with only engine braking, the fronts are cooler than the rears. In a couple of light braking intervals the same thing occurred, and in a few other light braking treatments temps were only 20F higher on the front. These results show there is a cooling factor at work in the PFC rotor. In spite of R53JCW/R56 caliper weight, its cast iron construction, and single piston design, the caliper combined with PFC rotors and Cobalt track compound pad has proven itself in a race application. I've heard of a few RSR team mechanical failures, but no failures due to brakes. No melted dust boots or seals either. Look below the right forearm of this gentleman where a bit of JCW caliper can be seen, and note the PFC rotor. This is on an RSR MINI competing at New Jersey. Here is a PFC rotor and R53 JCW caliper on an RSR MINI at VIR. Randy of RSR racing has this to say about the rotors he helped bring into existence. "...Grand Am rules require us to run stock factory calipers. For the R53 supercharged cars, that means the JCW brake package available from '03 through '06, including the GP series of cars. For the R56 Turbo cars, that means the standard brakes as delivered on cars except the JCW cars that use an upgraded package. The PF rotor... is directionally vented so it decreases the rotor temps dramatically. Our testing has shown racing temperature drops of over 200 degrees improving pad and rotor life. Another great benefit is, the rotors are two piece and use an aluminum 'hat'. The hat reduces brake heat transfer into the hubs, prolonging bearing and hub life. On the R53 the lower ball joints are also very close to the rotor. The lower rotor temps save the rubber ball joint boots which melt under high temps allowing the grease to escape. The rotor material is more durable as it lasts longer and extends pad life...it was not uncommon for the team to use two sets of stock rotors at an event weekend. We just replaced the first set of disc's that started life last year at Miller. That includes, Miller, VIR, the Daytona test weekend and the Daytona race. ...As the driver of a GP on the street, I've found it much smarter to use the PF rotors rather than spending extra money on a full brake system. No worries about wheel fitment, spacers, etc. No problems with brake bias, warranties, etc. . . ." A few additional reports from Randy: At the end of a 2.5 hour race the brakes would be smoking hot, but they could still get a practice session for the next race out of the pads, in other words the pads didn't cook from repeated exposure to excessive rotor heat. Be aware brake ducts are in use, but they've been used before too. The hubs no longer need to be replaced regularly as before when combined with stock rotors. Lubrication would be destroyed in hub bearings with the stock rotors and race conditions. Randy says to watch the RSR MINI in New Jersey's turn 7 (7/25, 1:00 PM ET, SPEED), brake torque exceeds the other cars there and it's noticeable; "superb" was the word he used. A commentator and fellow racers approached him afterwards asking what he did with the brakes since his last appearance there, "nothing but rotors" was his reply.
I have an R56 Justa Cooper. The stock front rotors on the Justa are just a tad bit bigger than the stock R53 rotors. The calipers are the same, just the caliper carriers and rotors are different. I got some slightly used rotors and Hawk HP+ pads, added the caliper carriers. Stopping power is greatly increased. While my 15" Flik Blast wheels fit over them, I've been informed by a local SA that some of the 15" MINI wheels will not.
Couple of comments: The replacement disc's are a lot cheaper than the original kit. The aluminum hats don't need to be replaced . . . only the separate rotors. I don't know the street cost of just the rotors so maybe Keith can clear that up. The replacement rotors come with new bolts, rings, etc. I put a set of Wilwoods on my '06 GP street car . . . great brakes, stop well, look good . . . no complaints. Unfortunately, I had to take them off (still have them, if interested). They fit the original 18" wheels . . . they fit the 17x7.5" OZ wheels I have w/ 5mm spacers. They DID NOT fit under the 15x8 Kodiak's nor the U06 949 racing wheels. The Wilwood calipers are wider and 'squared' and thus . . . hit the spokes. It would take a 10mm spacer to clear and the tires would stick out past the fender well. The dimples on the rotors could be used for depth calculations but that is not their purpose. They are there to keep the pad/rotor interface clean. I am yet to wear out a set of rotors to the dimples. We replace them when they develop tiny spider cracks on rotor surface. Bearing in mind that we are brutal on the brakes :mad5: . . . we still get about 5 to 10 hours of life out of a set of disc's depending on the track. The higher speed tracks are better for disc life as they have more time to cool. I think in a street application w/ occasional track use the rotors would last almost indefinitely. We would often use two sets of stock rotors on a race weekend AND replace the hubs every other race. These rotor have saved us lots of $$$. Please tune in to the Speed broadcast of the New Jersey race this Sunday, July 25 at 1pm Eastern. One of the Grand Am officials who was the spotter on the back side of the track approached me after the race and expressed his astonishment at the braking power of the winning 198 car. He specifically mentioned turn 7. Also, the Speed race announcers were allegedly discussing the same thing during the telecast. I have not seen it either as we are not given a preview, but . . . for a Mini fan . . . it will be VERY exciting. We won the race in convincing fashion. Lastly, I guess I'm not totally objective on this issue as team RSR worked with Performance Friction to develop these rotors. I welcome your comments ! Randy
Preview of Sunday's telecast on Speed Watch the braking when Owen passes the RRT 330 BMW . . . at about the 1:08 mark. Kinda says it all . . . Thank you PF Rotors!! (and Colbalt pads) [ame=http://www.youtube.com/watch?v=SJ2W6LkvRnU]YouTube - Conti NJ highlights.mov[/ame]
A bit off topic... but for racing the cost of these parts is pretty small compared to other costs in running. For the street it's something else. I just finished writing up an article on dampers (shocks or struts), and found that you can spend $13.5k on a set of hyperadjustable remote resevoir Moton Suspension Technology dampers. Be a total waste on the street. I think the sticker shock is because the price level expectation for rotors is based on the stock rotors, or other non-floating options out there. But like you point out, sometimes the more expensive part is less expensive to own when they are used as intended. another thing I noticed as I was looking for other floating options is that a lot of companies that make full floating offerings for racing don't even list them for the performance/street crowd. Means that to find a fitment one has to not be intimidated by looking at the hub/rotor dimensions and choosing from a catalog that has no listing by make or model of car. Not a lot of street drivers are comfortable doing that. Keep up the good work and keep on winning! Matt
After more time with the PFC Z-Rated pads designed for the R53 JCW kit (includes R56 front caliper with R53 rear caliper combo), I'm very pleased with their behavior. Consistent brake torque when required, no noise, moderate dust, and street friendly brake engagement. For a pad designed to tolerate lots of heat, it's a surprise to see low amounts of dust. Here's an article on Performance Friction's manufacturing processes. Performance Friction, State of the Art Braking Systems
Is the PFC Z-Rated pads their street pad? Is there another pad options than the PFC Z-Rated pads, something more dusty and loud that could do a good 5-9 track days a year?
Z-Rated compound is a street pad. There is also an endurance pad that compromises ultimate torque for pad & rotor longevity, and another pad compound that will provide plenty of torque when hot, but will hasten rotor wear at the same time. Both will squeal, dust, and etch wheels if left unwashed.
Man, i wish this was all an option 8-9 months ago as i just re-rotored and re-padded my car, not to mention my friend i pushed to the TSW MDM Kit (which is still awesome IMO). Keith have you done any brake cooling modifications or do you plan to ? And so i understand correctly: RSR Mini 198 has r53 JCW brakes aka r56 brakes, and 949racing 6ul wheels, right ?
No brake cooling for mine; I don't generate enough heat to need it. The cooling system that looks most promising to me for track day users is the challenge car plate. It fits close to the rotor and the hose is directed at the hub. I have an idea for creating a pressure differential within the wheel well I would like to try some day.
OK, i currently have the WAY brake ducts in the front bumper, but when it came time to install the rest of it, i didnt feel confident in removing so much of the radiator core. SO i will most likely do the above. MiniMania sells just the backing plates, anywhere else that may as well ?