Girodisc replacement rotor rings, sold
individually. Product listing is for slotted only, please contact us for
Girodisc now includes replacement mounting hardware with all rotor rings!
is a brake technology company that is dedicated to the development and
manufacturing of high quality brake components and brake systems. GiroDisc
products are designed and engineered for both street and track applications with
a comprehensive product line of two-piece floating rotors that are designed to
be a direct replacement for the factory rotors. The two-piece floating rotor
will improve braking performance, reduce unsprung weight and utilizes the
factory calipers and e-brake.
Unlike many “big brake” packages on the market, GiroDisc rotors also retain the
factory brake bias and outstanding pedal feel. High quality construction and
premium grade materials provide improved wear, increased rotor life,
minimized coning and greater cooling efficiency. GiroDisc rotors come
slotted and are also available with an optional drilled pattern.
The relentless pursuit of enhanced performance has earned GiroDisc multiple
victories in Porsche endurance racing. GiroDisc combines valuable lessons
learned at the track with the latest technologies to develop the highest
performance brake systems for Porsche.
The primary purpose of the Girodisc system is
to reduce unsprung and overall vehicle weight. The secondary purpose is
to increase the ventilation and cooling capacity of the brake disc while
retaining it‘s original dimensions. This is accomplished by using two-piece
disc construction. The central “hat” section of the disc is made from
6061-T6 aircraft specification aluminum.
The disc is made from cast iron, to the same specification and material as used
by professional racing organizations. It is a curved vane design,
developed in racing to act as a centrifugal pump to force cooling air through
the disc. The rotor and hat have a floating mount system, which utilizes
high strength alloy steel drive pins, manufactured by Girodisc to their own
specifications and cadmium plated for a long lasting corrosion resistance. These
pins take the load from braking actions while maintaining the axial and radial
float between the hat and disc. The pins are secured by grade 12 cap screws with
hardened washers. In order to keep the rotors from making noise when cold, the
pins are mounted with anti-noise spring clips on the rotor side which
allow the rotor to grow with heat expansion but eliminate the rattle and noise
associated with floating rotors. This float also allows the rotor to self center
between the pads.
Q: What is required to
install the Girodisc system? A: The Girodisc system is a direct replacement for the OE disc.
No modifications are necessary. The disc will bolt directly to the car
and work with OE calipers and pads perfectly. Once the Girodisc system
is in place, simply replace the cast iron rotor when needed. Some discs
are larger in diameter and come with caliper spacers. If longer bolts
are required, they are also supplied.
Q:How does reducing weight of the braking system benefit the
vehicle? A: The Girodisc will generally weigh between 4 – 8 lbs less than
the oe disc it will replace. This is due to the heavy cast iron hat
section being replaced with lightweight, high strength aluminum. The
mass of any vehicle requires energy to accelerate or decelerate.
Reducing the vehicle mass improves acceleration, and requires less
energy to be dissipated during deceleration. Rotating mass requires
additional energy in order to increase or decrease its speed of
rotation. Decreasing the mass of the disc has a great benefit due to
reduction in rotational inertia. This will allow more of the braking
force to be available to decelerate the vehicle, not the disc.
Additionally, the mass of the brake system is also unsprung mass.
Reducing the unsprung mass has the additional benefit of improved
suspension performance, resulting in enhanced ride and handling.
Rotating masses require additional energy to vary the plane on which
they turn. The lighter the disc, the quicker the response of the vehicle
steering due to the reduction in gyroscopic effect/rotational inertia of
the disc. As an example, compare the weight of the Ferrari 360 OE disc
at 18.2 lbs, and the Girodisc at 14 lbs. The Girodisc is 4.2 lbs lighter
per disc. Replacing all four discs will save 16.8 lbs of rotating,
Q: Why slotted discs? A: The edges of the slots continuously clean and refresh the pad
surface. This will allow the pads to have a maximized friction surface
always available. Additionally, they prevent containments from
collecting between the pad and disc interface.
The disc is lightened, decreasing its rotational inertia.
Slots prevent the formation of a water film on the disc in wet weather,
maintaining the best brake response.
A note on drilled discs: Girodisc does not recommend drilled discs for high performance track
applications. The rapid heating and cooling cycles will cause
cracking on the friction surface of a drilled disc. The use of high
friction or racing pads will exaggerate this condition. Most pad
manufacturers specifically recommend that their race pads not be used on
a drilled disc for this reason. Girodisc can drill discs for an
additional fee, if the customer is aware of the potential hazards of
drilling the discs.
Girodisc brake kits are available in drilled/slotted configurations
for high performance street use, please contact us for more information.
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