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The brake knockback, causes an intermittent mushy and long brake pedal and is pretty annoying under track conditions. The Z is known to suffer from this when stock and going to a much larger diameter rotor only makes this issue worse.
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| The Stoptech rotor dwarfs the stock 350Z rotor. At 35mm thick, it is thicker than the typical 32mm brake upgrade rotor. |
Stoptech came to our aid coming up with a front brake kit that used a large 355mm x 35mm rotor with their ST40 4 piston caliper with pistons sized for the stock rear brakes. Stoptech also set up the rotors to fully float. Floating the rotor means that it has about 0.012” of free play. This reduces distortion of the rotor when it’s hot. All Stoptech rotors are designed to float but their street rotors use conical Inconel spring washers to apply some spring tension to the rotor to reduce its rattling.
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| The Stoptech rotor hat has vanes that pump air between the hat and rotor and reduce contact area. This reduces heat transfer to the hub and allows a little more cooling air to the outside face of the rotor. Our rotor is fully floated race style with unsprung flat washers. This is more noisy than the normal sprung washers used for street applications. |
We wanted the rotors to move freely so they would be less likely to contribute to knockback. To achieve this the rotors were assembled to race spec with flat washers allowing the rotors to be totally free to move. The rotors use Stoptech’s Aero Rotor vane design that improves airflow though the inside of the rotor. The Aero Rotor’s hats also have directional standoffs to improve airflow to the outside face of the rotor and to reduce heat transfer to the hubs. Since our car is going to see a bunch of track use, we got slotted rotors as drilled rotors can crack under hard track use.
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| The Stoptech Aerovane rotors have internal cooling passages that increase in diameter from the inside to the outside to provide diffusion so cooling air can better pump through the rotor. |
We also requested the optional race caliper mounts for our kit. These mounts relocate the caliper in front of the rotor instead of on top. Locating the caliper in front reduces the amount of rotor runout the caliper will see, reducing the piston knockback. Between freely floating the rotor and using the race caliper mount, we hope to reduce the car’s sensitivity to wheel bearing condition.
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| Technosquare's Howard Watanabe removes the dust shield to make room for the larger front rotor. |
