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With the new master cylinder, calipers, and rotors installed, I was curious to see what kind of real-world difference the new system made, so I contacted Summit Racing and acquired an Autometer D-PIC. A standard 21?16-inch gauge, the D-PIC is an accelerometer capable of measuring parameters such as acceleration, deceleration, and lateral g's. Since the C3 isn't known for having a lot of extra dash space, and I'd already hidden a nitrous gauge in the ashtray, I looked for a way to mount the D-PIC on the A-pillar. Unfortunately, while Autometer offers a blue million gauge pods, they've inexplicably missed the C3. I did, however, acquire one for an '82-'92 Camaro/Firebird, which I was able to modify with a heat gun to fit my A-pillar and mount using trim adhesive. Wiring it up was simple: Autometer suggests including a 1-amp fuse, so I picked one up at the local auto-parts store and wired that into the positive power, which I got by tapping into the switched-power line going to the electric fuel pump. I similarly tapped into a ground wire that went to the engine block, then wired the third white wire to the headlight circuit. While you technically only need positive power and ground to run the D-PIC, the white wire causes the gauge to dim when the headlights are on, which is a good thing, as it would otherwise be bright enough at night to be distracting. Tuck all the wires out of the way, scrape off the excess adhesive, and off you go. Thanks to the kindness of our local sheriff and chief deputy, I was able to get a section of road closed off to allow for safe testing both before and after the installation of the new brakes. Setting up the D-PIC was easy: First I used the setup menu to make sure it was calibrated properly, then lined up the car to run it.  9 Once bled, install the...  9 Once bled, install the master cylinder, making sure not to drip any brake fluid on your paint. Keeping the bench-bleeding lines in place will minimize the amount of fluid leaking out of the outlets while you're trying to get everything bolted into place. Torque the bolts to 24 pounds.  10 Now, on to the calipers....  10 Now, on to the calipers. This is what we're replacing: a cast-iron four- piston unit that weighs 11.5 pounds. Remove the two 5/8-inch bolts holding it in place (one at the front, one at the rear, both on the other side of the caliper), unscrew the rubber brake hose from its fitting where it joins the hard line, and remove the clip holding it to it bracket.  11 Aside from the dramatic...  11 Aside from the dramatic weight reduction, the advantage of the Wilwood caliper (top) is in its increased clamping force. In addition to having two more pistons, the D8-6 calipers have larger pistons, with 75 percent more clamping surface than a stock caliper. While the D-PIC measures 0-60 times, rear-wheel horsepower, lateral and forward/backwards g's and quarter-miles, the 60-0 feature is what mattered to me. Press the "mode" button on the left until "60-0" appears, and click "enter." The unit will show "cal," then the word "GO." Once you start accelerating, it will indicate speed until you're above 60, when the whole dial will flash and command you to "STOP," and then display the braking distance once you have. I got in six runs with the stock calipers before picking up a nail in a rear tire. Stopping distances averaged 148 feet using threshold braking, with a best of 143 feet and a worst of 153. With the new brakes installed, my best six runs out of 11 averaged 138 feet, with a best of 135, putting the car about halfway between a stock C3 and a C4 or C5, which both stopped in something like 125 feet. I should note, however, that the rear tires locked up before the fronts did, which tells me the bias needs to be adjusted, since it should be the other way around. With that changed, I'd expect to see the stopping-distance numbers drop even more. As it is, the brakes have a much firmer, more responsive feel. While they are by no means grabby, it requires a lighter touch to threshold brake, as the greater clamping force means they tend to lock up quicker than stock brakes, requiring more skill to hold the tires at the limit of traction. This is as it should be. Of course, one of the greatest limiting factors on how quickly you can stop a car is how much road traction the tires give you--and I think it's about time we did something about that next. Special thanks to Bob Ingram, April Owenby, Paul at Arrowood's Automotive, and William Stoner.  12 Remove the sticker covering...  12 Remove the sticker covering the brake-line inlet on the inboard side of the caliper, and screw in the elbow fitting included with the braided-steel brake-line kit. One end of the fitting has an AN thread, while the other has a tapered NPT thread. Screw the tapered end into the caliper and orient the AN side so the brake line can easily mate to it. When that's done, screw on the line.  13 If you're changing rotors,...  13 If you're changing rotors, you'll need to do that now before reinstalling the calipers. After the initial installation, we upgraded ours to Wilwood’s drilled-and-slotted Polymatrix OE units.  14 The Wilwood rotors come...  14 The Wilwood rotors come in front- and rear-axle pairs, and are marked with an arrow to show which way they should turn.  15 Slip the rotor onto the...  15 Slip the rotor onto the wheel studs, and the caliper into its mounting position. After putting red Loctite on the caliper-mounting bolts, torque them to 70 pounds. Make sure the rotor is well seated before torquing the bolts, so it doesn't bind as you tighten things down.  16 With the front rotors...  16 With the front rotors and calipers in place, remove the C-clip that holds the brake-pad mounting pin in place and slide it out. Next, slide in the pads and replace the cross pin and clip.  17 Connect the caliper's...  17 Connect the caliper's braided-steel brake line to the frame hard line, using the included adapter fitting. If you've been letting the brake fluid run through the frame lines to flush them--which you should be--this is going to be a little messy. Be sure to wait until the fluid is running clear before connecting the lines.  18 While the rear Wilwood...  18 While the rear Wilwood D8 calipers have the same piston count (four) as the stock ones, the pistons are bigger, giving the D8s about 48 percent more clamping area. They install the same as the fronts, except the caliper bolts should be torqued to 55 pounds instead of 70. Once they're installed, it's time to bleed the air out of the system.  19 Completely fill the master...  19 Completely fill the master cylinder prior to bleeding. We used Wilwood's own 570 high-performance fluid.  20 Use the plastic lines...  20 Use the plastic lines from the bench-bleeder kit on the calipers; this will help keep fluid from squirting everywhere during the bleeding process. Start with the caliper farthest from the master cylinder and work your way in. Bleed only the top screws, and bleed the outboard screw first, then the inboard.  21 See the bubbles rising...  21 See the bubbles rising at the rear (right side) of the master cylinder? Bleed until those stop forming, and no more air comes out of the calipers. While fluid will not compress under pressure, air will, which means having air in your lines will cushion the force that the fluid would otherwise conduct to the brake calipers. This can result in both a soft pedal and less clamping force.  22 To test the decrease in...  22 To test the decrease in stopping distance with the new brakes, we installed an Auto Meter D-PIC performance meter from Summit Racing.  23 Since no one makes a C3...  23 Since no one makes a C3 Corvette A-pillar gauge pod, I used one from an '82-'92 F-body and modified it with a heat gun to fit my '72.  24 After using a file to...  24 After using a file to clean up the round opening in the face of the gauge pod, the D-PIC slid right into place. Since the included gauge-mounting bracket was a little too long to fit in the pod—it was bearing against the A-pillar itself—I shortened it (and the brass screws) using a Dremel tool.  25 To wire up the D-PIC,...  25 To wire up the D-PIC, I installed an inline 1-amp fuse holder and spliced into 12-volt positive power going to the fuel pump. I then grounded the D-PIC by splicing into a ground wire that went to the engine block, and tapped into the headlight circuit with the white dimmer wire.  26 Once everything was wired...  26 Once everything was wired up and we knew it worked, it was time to permanently mount the gauge pod. While the instructions say to use screws to hold the pod in place, I used an emblem/trim adhesive for a cleaner look, and employed a pair of C-clamps to hold it in place while it cured.  27 Here's the finished product,...  27 Here's the finished product, mounted enough out of the way that it doesn't interfere with the driver's hands on the steering wheel. While the D-PIC comes in several different configurations, I chose the Ultra-Lite because of the silver rim and face, which will come close to matching the white-faced gauges I plan to install later.  28 With the dimmer wire installed,...  28 With the dimmer wire installed, the D-PIC is substantially less bright once the headlights are on (as shown here), which keeps it from being distracting at night.
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