The Roadster Shop's IRS also uses some Corvette components in the rear, namely the hubs and carriers. All the brake components for that application were found in Wilwood's rear brake kit for C5/C6 Corvettes (PN 140-8032). It includes Superlite four-piston calipers that are also made from billet aluminum. These four-piston calipers are said to have the highest clamping efficiency and the lowest deflection of any caliper in its class and are equipped with radial mounts. For this particular application Wilwood's unique rotor hats with integral drums (PN 170-8169) were used to accommodate the stock Corvette internal expanding parking brakes.
A special feature of both the front and rear brake kits are the two-piece hats and rotors that are held together with a series of 12-point screws. These fasteners are drilled for safety wire and it is critical they are secured in the fashion shown here (for more on safety wiring, check this month's Shop Manual column on page 132) along with a quality thread-locking compound.
Dean Livermore and the crew at HRBD in Phoenix have made amazing progress on the AMSOIL/STREET RODDER '59 Chevrolet. With the new Roaster Shop chassis there's no doubt the Impala's ride and handling will be superb, and with Wilwood discs at all four corners, bringing the Chevy to a stop will require considerably less real estate than the original drums required. Watch future issues of SR for more updates and check out streetrodder.com for more information on the car and the 2014 AMSOIL/STREET RODDER Road Tour.
Safety Wire Tips From Wilwood
•Using standard (0.032-inch-diameter) stainless steel safety wire, begin by sliding the wire through two of the holes that are 180 degrees apart (see upper diagram). The twists should be six per inch, minimum, with a maximum of 12 twists per inch. Also, only safety wire bolts in pairs, as shown in the bottom diagram. Do not string along.
•Note: Safety wire (also known as lock wire) is used to prevent a fastening device from coming loose. It is not a substitute for a secure fastener.
•Safety wire must always tend to tighten the bolt. For a bolt or screw that is tightened by turning it in a clockwise direction, the installed safety wire must tend to pull in a clockwise direction. Select the bolt head holes that would best produce this tightening effect.
•Safety wire must be tight when installed.
•Safety wire must be the proper size.
•Safety wire must never be over stressed. Care must be taken when twisting safety wire together or pulling it tight, not to tighten it so much that it will break under even a light load. Making sharp bends or kinks in the wire must be avoided because they produce stress points in the wire and could cause it to break.
•Always use safety wire pliers to twist the safety wire.
•Safety wire ends must be secured. When installation is complete, the remaining ends are twisted together to form a pigtail (see upper diagram). It is standard procedure to wrap the pigtail around the part being safety wired and tucked down out of the way.
Begin by sliding the wire through two of the holes (left) that are 180 degrees apart. Twist the wire as shown (below) using safety wire pliers. Now slide one wire through two of the holes (180 degrees apart) and wrap the other wire around the bolt. Twist the wires together to form a pigtail.
•Torque values must never be changed to obtain an ideal safety wire position!
•Never reuse safety wire. If you make a mistake, throw that piece away and try again. Safety wire is cheap.