Wilwood Grand National - Manual

4700 Calle Bolero • Camarillo, CA 93012 Sales: 805 / 388-1188 • Fax: 805 / 388-4938 • www.wilwood.com
86A (11/01)
ORDERING INFORMATION: CALIPERS:
GN III/ST CALIPERS, 3.50” MOUNT WITH THERMLOCK
®
PISTONS
FRONT MOUNT REAR MOUNT
PART NUMBER PART NUMBER
BORE SIZE DISC WIDTH RH LH RH LH
1.75/1.38/1.38 1.25” - 1.38” 120-6951-FS 120-6952-FS 120-6951-RS 120-6952-RS
47,8/44,5/44,5 mm 31,8 - 35.1 mm
GN III CALIPERS, 3.50” MOUNT WITH STAINLESS STEEL PISTONS
1.75/1.38/1.38 1.25” - 1.38” 120-6478-FS 120-6479-FS 120-6478-RS 120-6479-RS
47,8/44,5/44,5 mm 31,8 - 35.1 mm
Caliper Highlights:
Wilwood’s GN lll is a time proven caliper that has been
widely used with 5 on 5 hubs for stock car, road course, and
off-road competition. The 3.50" mount configuration
incorporates this legacy of enduring performance, with
options available for the latest brake system heat
management technology.
3.50" mount with taller height for 12.19" rotors. The new
generation GN lll uses the same popular 3.50" mounting
pattern found on the Superlite caliper series, but are built with a
taller mounting height. This feature accommodates the installation of
12.19" diameter rotors on the same spindle brackets used with a Superlite
caliper and 11.75" diameter rotor. The GN lll can be run with either a 1.25" or
1.38" thick rotor. This makes it possible to run three different bolt-on brake setups, without the need for
bracket changes on the spindle.
High strength, low deflection, and superior stopping power. Each GN lll is manufactured from a precision casting using a
tight grained, high-density aircraft alloy. It is a two piece, closed bridge design with grade 8 thru-bolts and external stiffening ribs.
The GN lll utilizes a unique six-piston configuration that generates high clamping force with balanced loading for extremely even
pad wear. The 1.75" / 1.38" / 1.38" bore pattern contains a total of 5.44 square inches of effective piston clamp area. This makes
the GN lll one of the largest calipers available. The caliper bridges are fitted with stainless steel plates to reduce wear and
provide the smoothest pad operation. Dual center bridge bolts add to the overall caliper strength and provide positive retention
for the top loaded pads. Dollar for dollar, this combination is unmatched for high strength, low deflection, and superior stopping
power.
Thermlock ® or stainless steel pistons. The standard GN lll uses six stainless steel cup pistons. Stainless is used for its slow
heat transfer properties and high corrosion resistance. The GN lll/ST models feature Wilwood’s exclusive Thermlock ® pistons to
minimize the direct heat transfer from the pads. These pistons can reduce caliper temperatures by more than 30% over stainless
steel pistons, without the need for fluid recirculation systems. Fluid temperatures are reduced, seal life is extended, and caliper
service life is prolonged with less distortion and reduced wear in the piston bores. Cooler temperatures translate into maximum
performance and ultimate reliability over the longest run. Using EXP 600 Plus racing brake fluid will guarantee success with
trouble free performance in all extreme conditions.
Big pad volume. The 3.5" mount GN Ill calipers use the same 7520 style pad as the traditional GNlll caliper. The longer and
wider pad face provides a full two cubic increase in pad volume over a 7320 style Superlite pad. Larger pads mean longer wear
and additional heat resistance in extreme duty conditions. Six PolyMatrix compounds are available to match brake torque and
heat range requirements on any application.
GN III AND GN III / ST CALIPER
with 3.50” MOUNTING TABS