For most of us, performance has always been an important part of this hobby and will be until the sensation from punching the throttle and being shoved back in the seat no longer creates an ear-to-ear grin. However, while acceleration is a thrill, there are occasions when deceleration can create an even greater, albeit less enjoyable sensation often referred to as the pucker factor. Chances are if you drive any car, including a street rod, past the end of your driveway, sooner or later someone is going to do something stupid in your path; it's one of those experiences that makes every nerve ending in your body, particularly those in the seat of your pants, go on red alert. The ability to stop quickly may be the difference between a bent car and a bruised ego (or something much worse) and continuing on your merry way no worse for wear.
When our Road Tour car rolled down the assembly line in 1952, the Chevy was equipped with drum brakes at all four corners that were barely adequate to cope with the speeds generated by the 105-horse inline six. Of course, with the original suspension and 6.70-15-inch bias ply tires, better brakes would probably result in longer skid marks rather than shorter stopping distances. But that was then; now a state-of-the-art Morrison chassis and several times more rubber meets the road, and we needed brakes to match, so we turned to Wilwood for proper stoppers. To give our Chevy whoa commensurate with the go, we opted to have the crew at Woody's Hot Rodz, builders of this year's car, install Wilwood's Superlite Big Brake kits (part number 140-9919-D for the front, 140-9219-D in the rear). The front kits are engineered as complete assemblies for conventional pin, non-ABS front spindles, and the rears include parking brake assemblies.
Here's a look at the components in the kits:
Calipers
Wilwood has always been a leader in disc brake caliper technology, a theme they continue with the Superlite 6-Piston SL6 Calipers we used on the front of our Chevy. Based on a fully CNC-machined billet body, these calipers use six stainless steel pistons with what is called a differential bore configuration. Adapted from Wilwood's racing technology, it means that the piston sizes are staggered, in pairs, along the length of the caliper body. According to Wilwood, "clamping pressure is proportionately distributed to provide balanced pad loading with even wear properties at all loads and temperatures. Pad life is extended and performance is measurably improved." We all know this, as they really work.
In the rear we used Superlite 4R calipers. 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.
Another unique feature found on both styles of calipers is described as radial mounting--it allows for adjusting the caliper in two planes (closer or further from the centerline of the spindle pin or axle on one plane--centering the pads over the rotor on the other).
Hubs
The front hubs are forged from aluminum, then CNC-machined. They come complete with bearing races installed and new bearings, grease seals, screw-on billet aluminum hubcaps, and 1/2-20 RH grade-8 wheel studs.
Rotor Hats
Think of these as the mounts for the rotors. The hats bolt to the hubs, and the rotors bolt to the hats.
Rotors
Wilwood offers two styles of rotors: SRP rotors are cross-drilled and have slots in the faces not only for aesthetics, but the venting and cleaning action of the holes and slots reduce pad glaze, dissipate surface heat, and minimize irregular pad build-up on the rotor faces. To prevent corrosion, SRP rotors are treated with a silver zinc wash. GT rotors have asymmetrical face slotting and individual dynamic balancing, but are not cross-drilled. We went with the 13-inch SRP versions for front and rear.
Stopping power for the '09...
Stopping power for the '09 Amsoil/Street Rodder Road Tour Chevy will be generated by Wilwood disc brakes on all four corners.
Brake Pads
The effectiveness and wear rate of brake pads vary dramatically. Some have to get hot to work their best while others fade rapidly when they get hot; some last for a long time but are hard on rotors, while others wear rapidly. Our calipers came with PolyMatrix brake pads that offer high resistance to fade, long wear, and the low rotor abrasion.
Caliper Brackets And Hardware
Our brake kits came with light but extremely strong aluminum caliper mounting brackets with steel threaded bolt hole inserts, grade 8 fasteners, and alignment shims. The rear caliper mounting brackets also secure the parking brake assemblies to the axle tubes.
Parking Brake
There are a number of methods incorporating a parking brake into rear disc brakes, such as calipers with built-in mechanisms to mechanically apply the brakes, small, separate mechanical calipers on the rear rotors, or a disc on the pinion yoke and the internal shoe design used in our Wilwood kit. The latter not only works best, but it's completely hidden inside the rotor hat for a clean look.
The Wilwood billet hubs are...
The Wilwood billet hubs are drilled for both Ford and Chevy bolt patterns. Rather than press-in studs, these thread in from the back side of the hub. Thread locking compound ensures they stay put.
Other Parts And Pieces
To complete the brake system we used a Wilwood master cylinder (part number 260-9439-P) and proportioning valve (part number 260-8419).
9-Inch Tips
Without a doubt, the most popular rear end to put under any high-performance vehicle is the Ford 9-inch. They're extremely rugged, a wide range of gear ratios are available, and there are a variety of traction-enhancing differentials that can be installed. About the only problem with them is OEM units are getting harder to find, but thanks to Strange Engineering, axle housings and every other part required to build a new assembly are as close as your phone. The Strange axle housing under our Chevy had all the necessary brackets welded in place at Art Morrison's, so all the guys at Woody's had to do was install the center section and axles. Speaking of the center section, we used a Strange S-series case. Made from nodular iron it accepts 28, 31, 33, and 35-spline axle combinations and is clearanced internally for posi units.
When it comes to axles for street use, Strange has developed the very affordable S/S series. Made from forged steel these axles are induction hardened after machining making them much stronger the OEM shafts. Available in 28 and 31-splines, we chose 31-spline for the 38% greater torque capacity they offer. For street and strip use, Strange offers the larger diameter S/T series with 35 splines.
Wilwood's SLP rotors are...
Wilwood's SLP rotors are vented, drilled, and slotted. They bolt to a hat (right), which in turn bolts to the hub.
New gears and bearings will initially generate higher than normal operating temperatures, and while it's not often followed, there is a break-in procedure for street gears: No harsh acceleration. Drive the vehicle 50 miles, then let the car sit for an hour to allow the differential to cool down. Repeat this sequence for a total of 250 miles. At 500 miles, drain the fluid and clean the inside of the housing. Re-seal the housing and fill with the proper amount of gear lube and add posi additive (if needed).
Although following the break-in procedure is advised, another way to ensure a long life from our U.S. Gear ring and pinion is opting for the Micro Blue process now offered by Strange. A micron thick finishing procedure, Micro Blue allows the gear lubricant to be more effective that reduces operating friction and wear.
So What's Next?
Our Road Tour Chevy is shaping up, but the crew at Woody's still has a lot to do and a few tricks up their collective sleeves that we'll be passing along to you. We can guarantee the end result is going to be worth waiting for.
Thread locker is also used...
Thread locker is also used in the fasteners securing the rotors to the hats and they must be safety wired as well.
New bearings and seals are...
New bearings and seals are part of the package. There are several common techniques for adjusting wheel bearings. One is to tighten the bearings to 10-12 ft-lb while spinning the hub then back off one flat or until the cotter pin will fit. Another is to tighten as described, loosen the nut then tighten it as much as possible with your fingers--if necessary, tighten with a wrench to the nearest hole.
With the hub installed the...
With the hub installed the hat and rotor simply slides over the studs. Although the wheel would hold the assembly in place, two flathead screws are used.
The Wilwood caliper mount...
The Wilwood caliper mount bolts to the spindle, shims are used to move it closer to or further from the rotor.
Studs on the bracket mount...
Studs on the bracket mount the caliper. Shims are again used to precisely locate the pads on the rotor.
With the six-piston calipers...
With the six-piston calipers positioned and the nuts snug the top of the rotor should be even with the top of the pads. If adjustment is necessary, shims can be added or removed.
For ease of maintenance, the...
For ease of maintenance, the top-loading brake pads can be inspected and serviced without the need to remove the caliper from the mount. Standard kits include black calipers; red or polished calipers are also available.
The Strange S/S 31-spline...
The Strange S/S 31-spline axles are held in the housing by a pressed on wheel bearing and a lock ring. If the stock bearing retainer is used it goes on first, then the seal, bearing and lock ring. Strange bearing retainers are U-shaped so they can be installed after the axles are in the housing.
This is one of the reasons...
This is one of the reasons Ford 8 and 9-inch rearends are so popular. The wheel bearings are pressed onto the outer end of the axles and retainers hold them in the housing. If an axle breaks, the wheel stays attached. Later 8.8 and GM 10 and 12 bolt rears use C-clips on the inner ends of the axles, which means the wheel can come off if the shaft breaks.
Strange also supplied the...
Strange also supplied the new rear axle housing. Compared to the OEM unit these are much more rigid, have much more weld area for the axle tubes, and feature a reinforced faceplate.
The Strange center section...
The Strange center section is made from nodular iron (like the highly prized Ford N pieces were) and have additional webs for strength. Resist the temptation to use "regular" nuts and lock washers when installing the center section. Jet nuts (nuts with flanges) or nuts with copper washers should be used to keep gear lube from seeping down the studs.
There are several configurations...
There are several configurations of Ford axle housing ends. Which end you choose will determine the wheel bearings and brake kits required. This is the late-style big Ford design.
This bracket is used to attach...
This bracket is used to attach the parking brake assembly to the axle housing. It also accepts the caliper mounting bracket.
Wilwood's rear disc brake...
Wilwood's rear disc brake kit uses a very effective internal expanding style parking brake.
Here the caliper mount has...
Here the caliper mount has been attached to the parking brake bracket. As in the front, shims can be added or removed to bring the caliper closer to the disc.
The retainer flange on the...
The retainer flange on the axle holds the axle assembly in the housing and secures the parking brake assembly to the axle housing. Access to the nuts is through a hole in the axle flange.
As with the front brakes,...
As with the front brakes, the rear calipers mount on the two studs. Again, to position the brake pads on the rotor, shims are used to move the caliper away from or closer to the centerline of the axle.
Like the fronts, the four-piston...
Like the fronts, the four-piston rear calipers also feature top loading pads. Note the two brake bleeders; they should be at the top of the calipers as shown.
Wilwood's master cylinder...
Wilwood's master cylinder is unique in that it has outlets on both sides and it can be mounted to the firewall or floor bracket via the flange, or to a frame rail by holes at each end of the reservoir. When the plumbing is done a Wilwood proportioning valve will be installed.
For a brake pedal, Woody's...
For a brake pedal, Woody's modified a '68 to '72 under dash assembly. Swing pedals have the distinct advantage of leaving more room under the car for exhaust and other components.
To accommodate the shape of...
To accommodate the shape of the '52 toeboard, the pedal was reshaped and shortened slightly.
The Chevelle pedal bracket...
The Chevelle pedal bracket was shortened and two brackets were added to serve as attachments to the dashboard.
Four bolts secure the bracket...
Four bolts secure the bracket to the dash while two of the original Chevelle studs will be used on the firewall end. Those same studs will also hold the master cylinder in place.
Positioned below the steering...
Positioned below the steering column, the brake pedal can be used with either foot. The stock pad will be swapped for something better looking from Lokar.
A simple clevis attaches the...
A simple clevis attaches the master cylinder push rod to the pedal. A tab on the pedal (to the right of the clevis) activates the stock Chevelle brake light switch.
There's no need to hide Wilwood's...
There's no need to hide Wilwood's stylish master cylinder under the floor. Besides, mounted to the firewall checking the fluid is much more convenient (which means it's more likely to be checked regularly).