Upgrading your brakes can provide more than just increased and more reliable stopping power in extreme conditions. In the case of installing a carbon-ceramic system, it means a reduction in reciprocating mass and sprung weight, faster steering response, quicker acceleration, quicker deceleration, and improved handling response. And, let's be honest, they just look cool!
To test out the benefits of Wilwood's carbon-ceramic brake system, we hooked up with Ultimate Street Car Association (USCA) track day enthusiast and '07 Z06 owner John Parsons, who happens to be an engineer and serious car guy. John was preparing for a full weekend of track time on the road course at Daytona International Speedway, and was looking to find an increase in performance for his Z06.
It's a misconception that switching to carbon-ceramic brakes gives you stopping improvement because of their resistance to heat and its negative effects on braking performance. While carbon-ceramics do dissipate heat faster than cast-iron or other alloy brake systems, their main benefit is a massive reduction in weight versus metal. In the case of our Z06, the Wilwood C/SiC carbon-ceramic rotors weighed half that of the cast-iron rotors we removed. Lower mass coupled with better resistance to heat-induced fade, means you can drive deeper into corners before braking and that equates to faster lap times.
This reduction in weight at the wheels provided numerous benefits, while still being fully functional and capable for use on the street. For anyone competing in USCA events, the entry vehicle must be legitimately street legal. While hard-core road racing brakes would provide enormous stopping power on a road course, they would also be unmanageable for street driving. Wilwood's carbon-ceramic system gives increased performance on the track, while still being honestly viable and safe for the street. The one downside, aside from cost, is that your driving style will have to be adjusted because of the much more rapid heat dissipation of the ceramic system, and its need for a minimum amount of heat to function optimally. But those are easily overcome to gain the benefits of new technology.
01-02. With the spindles removed for our brake upgrade, it provided the perfect opportunity to perform some other upgrades. The factory uses an eccentric on the lower control arm for adjusting camber. On the street or autocross this is fine, but on road courses with rumble strips, throwing a car hard onto the rumble strip can lead to the eccentric moving and throwing camber out of adjustment. The Vansteel lower camber plate kit (PN VS-97459-1) eliminates this problem. The blocks are CNC’d aerospace aluminum, and the bolts are zinc Class 10 fasteners. This moves the camber adjustment to the upper control arm with the use of shims, which makes adjustments easier when at a track or autocross event, with no need to get under the car.
03. Another upgrade was switching out the stock hubs (left) for Vansteel’s heavy-duty racing hub assembly (right), (PN FBRB-9708SKFHD). It features higher load, larger diameter bearings, and higher temperature seals. The stock Z06 bearing usually only lasts one to three races when running full road courses constantly, whereas the Vansteel unit can typically survive a whole year’s worth of racing. These hubs fit C5 and C6 models (except C6 ZR1 and ’09-’13 Z06), which are interchangeable between front and rear, and can maintain a sustained preload of 1.2 g’s. The bearing hubs also feature the correct ABS sensors, so it’s a plug-and-play unit. It’s also what you find under a ZR1 Vette.
04. The lug studs on the Vansteel hub are heavy-duty ARP units, with extra length to accommodate different wheels and eliminate the effects of heat growth studs experience from heavy braking.
05. At the start, our subject Z06 was equipped with aftermarket drilled steel rotors, that weighed in at nearly 20 pounds apiece. The problem with drilled rotors, in extreme applications like this, is they can develop fractures on the face of the rotor after numerous heat cycles. Another thing is that for every hole drilled in the face of the rotor, that’s less surface area for the pads to grip for stopping.
06-07. For securing the ARP bolts holding the hub assembly to the spindle, Vansteel recommends these Nord-Lock washers. Unlike a normal lock washer, the Nord-Lock pieces use two flat washers with teeth that go underneath the bolt head. These provide a positive lock against the bolt, and hold tight even under extreme heat.
08. Once the bolts are torqued down, the ABS plug from the new hubs is secure to the factory tab on the spindle.
09. Here’s how our revamped spindle looks now. At first glance, you wouldn’t think there’s anything different from stock. But internally, this assembly can take way more use and abuse than the stock setup.
10. Wilwood’s C/SiC rotors are made from a proprietary carbon-ceramic material developed from Wilwood’s extreme-duty military-spec rotors that have superior heat capacity versus conventional iron or titanium rotors, higher thermal conductivity (they can dissipate heat faster than conventional rotors), and offer tremendous weight savings as well. The Wilwood C/SiC rotors weighed in at 9.1 pounds apiece, less than half the weight of the ones we took off (18.3 pounds). That lighter weight means less reciprocating mass and parasitic loss on the car’s drivetrain. The C/SiC rotors use Wilwood’s exclusive Bobbin Mounting System that prevents rotor rattle.
11. The Wilwood caliper mounting bracket provides for adjustment to center the calipers on the rotor using the included washers. Because of the various manufacturing tolerances that have to be dealt with between the aftermarket and OE manufacturers, Wilwood provides for this to make installation easier on the customer.
12. The clamping force on our new rotors is provided by Wilwood’s six-piston AERO6 calipers up front and AERO4 four-piston calipers in the rear, both finished with Wilwood’s Quick-Silver proprietary nickel coating. The AERO6 bolts to factory spindles and work with the factory master cylinder. The caliper body is forged aluminum, and its closed bridge design gives the AERO6 more integrity with less flex under heavy braking. The Quick-Silver finish coats the exterior and interior of the caliper, reducing wear in the piston bores. The AERO4 rear calipers offer superior clamping force over factory calipers and integrates with the factory internal shoe parking brake system.
13. For installation, the calipers have to be centered on the rotors as precisely as possible, so a dial indicator or digital measuring caliper will be necessary. You should have the same amount of space between the caliper and the rotor on each side. As we said in caption 11, the washers need to adjust the caliper’s mounting position, so it can be centered on the rotor.
14. With the calipers centered, it was time to install the pads. The closed bridge design of the AERO6 and AERO4 calipers means the caliper must be dismounted from the spindle before pad installation. To install the pads, you first remove the retainer snap ring, then the retaining pin can be tapped out.
15. The pads in the AERO6 and AERO4 brake kits are specially formulated for carbon-ceramic rotors. Conventional pads cannot be used with carbon-ceramic rotors; they’ll destroy the face of the rotor. The special Wilwood pads are designed to provide the most consistent stopping performance possible both at operating temperature and while cold. Like old-school organic brake pads, carbon-ceramic brakes operate best when they’ve got heat in them.
16. Included with the kit are new brake hoses and fittings to plumb the calipers into the factory hard line on the frame.
17. On the rear brakes, Sometimes the rotor can make contact with the backing plate in this area. Before installing the rear brakes, it’s best to use a grinder and add some clearance so you don’t risk the backing plate cutting into the rotor’s rear face.
18. You’d think a 14-inch diameter rotor this thick would be a heavy proposition. But the main benefit of switching to carbon-ceramic brakes is much lighter weight. A similar cast-iron rotor of the same thickness and diameter weighs in at over 18 pounds, while our new Wilwood C/SiC rotors tip the scales at a featherweight 9 pounds. On the road course at Daytona, the lighter reciprocating weight at all four corners translated into quicker steering, quicker acceleration, and lighter weight on the suspension, which had a positive effect on handling.
19. The last step was bleeding the brakes after we filled up the system with Wilwood’s EXP 600 Plus high-temp brake fluid. Fully synthetic, it features a wet boiling point of 417 degrees Fahrenheit, and has been tested up to 626 degrees. Its formulation resists aeration and compressibility after it has been heated and pressure cycled a few hundred times, and also low moisture affinity to slow the absorption rate of water vapor.
20. All wrapped up, here’s how the new brakes look behind our Forgeline GA3R wheels. After a full weekend of track time at Daytona, we were amazed that the rotors still looked like new and showed no signs of wear. And the benefits of lightening the rotating mass at the wheels translated into quicker lap times, more responsive steering, quicker baking allowing for faster entry speeds into turns, and more handling agility because of the decrease in sprung weight. This all while accelerating and decelerating between 150 mph and 70 mph.