There’s nothing that ruins the sexy look of an upgraded wheel and tire package like a dinky stock disc lurking behind the hub, leaving way too many inches of open space between itself and the outer rim—except perhaps a drum brake. Either way, they’ll distract from the way a good wheel makes the car’s image.
Aesthetics count in hot rodding, but were just picking on vanity here. Big brakes are actually about much more than looks; they have proven stopping benefits for guys who like to drive their cars hard and need repeatable performance. Around town with light braking, the benefits of a big brake package wont be quite as apparent. Good pads and tires will make more of a difference, but when subjected to repeated hard braking the increased thermal capacity (the ability to absorb and transfer heat) of larger diameter rotors will dissipate heat better to help prevent brake fade. As for why six-piston setups are so popular with those same aggressive drivers versus four-piston, its more than bigger equals better. The extra pistons aid in braking consistency by putting a more evenly spread clamping force on the brake pad. That will improve brake pad wear and decrease tapering of the pad at the leading edge.
This is the Challenge Series six-piston brake package for ’70-78 F-bodies (PN 140-12278), which is also correct for our late X-body Nova. The key to affordability here is the newly designed one-piece 12.88 diameter rotor that mounts to OE spindles with forged billet aluminum hubs. The caliper is the same found in the Superlite package, so the braking performance is great. Currently ’60-70s GM and Mopar packages are available, as well as OE Mustang II and Wilwood Mustang II replacement Pro-Spindles, but more are on the way.
But even with all that in mind, when it comes to actually laying down the cash for a full six-piston upgrade on a muscle car, many hot rodders suffer from a bit of sticker shock. That’s because most six-piston systems hover in the $2,000 range. Heck, even a lot of nice four-piston setups are around $1,500.
...many hot rodders suffer from a bit of sticker shock. Thats because most six- piston systems hover in the $2,000 range.
Wilwood recognized the price gap, as well as a huge pent-up desire in the marketplace, and began looking for a way to bring the price down dramatically without sacrificing quality or performance. Their answer is the new Challenge Series six-piston brake kit. What you get is a package with performance that delivers braking on par with Wilwoods next step-up six-piston kit, the Superlite 6, but comes in $700 cheaper with a price of $1,099.99. That makes them by far the least costly six-piston big brake kit that we know of, and you can buy them right now at SummitRacing.com for that price.
Considering the EcoNova was in need of a brake swap to ready it for autocross duty, and, of course, to fill up our 18-inch Boze Pro Touring wheels better, we gave Wilwood a call to get our hands on one of the first kits available. Want to see the whole swap process? Check out Wilwood.com and YouTube.com/PopularHotRodding for the video.
1. Installing a Wilwood big brake kit requires modifying the spindle for a different style caliper mount. Two factory boltholes need to be drilled out to a larger size and re-tapped. This can absolutely be done on the car without pulling the spindle, but the machinists at Wilwood are perfectionists and wouldn't hear of it.
2. Using the diagram included in the Challenge Series instructions, the factory brake caliper mounts get the knife as well. We used a bandsaw, but a Sawzall will work just as well if you decide to perform spindle surgery without removing them from the car.
3. The kits adapter bracket bolts into the newly drilled and tapped boltholes on the front of the spindle, and the caliper bracket bolts to the back side of it. Note that the forged aluminum hub helps minimize the unsprung weight. The kit also includes all necessary wheel bearings and hub seals.
4. The countersunk Allen screws on the rotor are actually there to keep the rotor in place when swapping pads. The wheel studs are burly ½-20, so a new set of front lug nuts may be required. Ours were 7/16-20 previously. The aluminum hub looks long, but its overall height is roughly the same as the stock dust cap.
5. An equivalent size four-piston caliper may have the same swept area on the pad, but the pistons would be spread further apart, resulting in less even pressure application. The different bore size of the pistons is because more force is required on the rear piston in order to counteract the natural tendency of the pad to clamp harder on the leading edge and create tapered wear on the pad. Thats also why calipers like this are directional.
6. To ensure the caliper is centered over the rotor, Wilwood includes shims in each brake kit. This makes up for OEM inconsistencies and allows the caliper to engage equally on both sides.
7. Wilwoods stainless steel braided lines (PN 220-7056) arent included in the brake kit, but are a recommended upgrade. The braid protects the hose from damage, and also will prevent expansion under pressure. Our lines were original and very dry, and probably dangerous.
8. We've never put so much stopping power on a car for so little investment before. We cant wait to bed the pads in and see what these six-piston front disc brakes are worth under hard use.
9. We had no brakes on our Currie 9-inch so we added Wilwoods 12.90-inch rear kit with integrated parking brake for Ford 9-inch rearends (PN 140-9219). The parking brake assembly is the first piece that needs to be installed.
10. Some axles, such as our Currie units, will require this spacer ring. It slips around the center of the axle flange to help center the rotor hat.
11. You can see here that the EcoNovas driver-side rear caliper will be a front-mount style. Thats because the staggered shock arrangement found on most Novas and many F-bodies will interfere with a standard rear-mount-style caliper. No worries though; Wilwood has all the parts in stock to address this common issue. Note that just like the front caliper brackets, the rear is provided with shims to center the caliper on the rotor.
12. Wilwood kits dont include a new parking brake cable, but the brackets should work with original-style cables without issue. The flipped caliper location will require specific adapter parts, however.
13. Currently, a one-piece matching rear rotor isn't available for our application, so we are using Wilwoods two-piece rotor with an aluminum hat. Since Wilwoods four-piston caliper has the same external dimensions as the six-piston, they make a nice match visually.
14. Many problems after a brake upgrade arent from the brakes themselves; theyre from poor biasing on old or cheap proportioning valves. Most older prop valves werent designed to properly bias four-wheel disc brakes, especially not large multi-piston ones. Its a good idea to swap these out for a quality replacement when doing any brake upgrade.
15. Wilwood always recommends upgrading to a matched master cylinder with the right piston size for the brake package. The EcoNovas master cylinder was old and in questionable condition, so the Wilwood swap was a no-brainer. Wilwoods master cylinders also come with this trick bleeding kit that takes the hassle out of the process.
16. There isnt any slicker looking master cylinder out there (PN 260-8555-p). The smart money is to junk the stock prop valve and swap to a Wilwood unit with the bias adjustment built in, like the one we plumbed in here (PN 260-11179). Now we can dial in the brakes for the best balance.
17. We love how the Challenge Series kit fills up the space in the Boze Pro Touring wheels. By the way, since the calipers are the same, if you ever decide you want to upgrade to Wilwood's two-piece rotor, its a simple swap. Want to go 14-inch? A rotor and different caliper mount bracket is all that's required.
