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. Thermlock® pistons are also available for the 6.00” mount, see page 109 for details. Using EXP 600 Plus racing brake fluid will guarantee success with trouble free performance in all extreme conditions.
The 3.50" mount GN Ill calipers use the 7520 style pad. 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. Four brake compounds are available to match brake torque and heat range requirements on any application.