JMS engineered these new caliper...
JMS engineered these new caliper brackets to accompany the slotted and cross-drilled rotors that are about 1-inch smaller in diameter. The kit comes with all the installation hardware as well.
In the last 20 years, wheel and tire choices have evolved tremendously for our Mustangs. We can remember trying to decide whether to stick with 14-inch wheels, or spend the extra $60 and live a little by ordering up 15-inch rims! Boy, have times changed. Even the most inexpensive econoboxes come standard with 16- and 17-inch wheels. What's more, brakes on most cars have grown proportionately, and in a lot of cases, won't even accept a measly 15-inch wheel. But, really, what Mustang driver would even look twice at a puny, little 15-inch wheel anyway?
Well, would you believe, one of the best-selling wheels of all time is a 15- incher. Yep, the 15-inch Weld Draglite is the most popular drag racing wheel out there, and for good reason. A 15x8-inch Draglite weighs in at less than 14 pounds, whereas a stock 17x8-inch aluminum wheel can weigh as much as 50 pounds! Saving that much unsprung weight is huge when it comes to getting your 'Stang down the quarter-mile.
Another advantage of using a 15-inch race wheel is that it enables you to run a taller tire. That means more sidewall and a better grip on the strip. A softer sidewall doesn't shock the tire as hard, and lets the contact patch actually grab the pavement rather than spin. Don't get me wrong--the drag radials do a great job of hooking most street cars, but in bracket racing, consistency is key, and the DOT wrinkle-wall drag tire is a hard act to follow.
The only problem is that the '05-and-newer Mustang has such large rear brakes, a 15-inch wheel won't clear the caliper, so it wasn't an option. Until now…
JMS Chip and Performance in Lucedale, Mississippi, has the solution--the JMS S197 Dominator Rear Brake Kit ($219). It's a kit that allows the mounting of 15-inch drag wheels without degrading your braking performance. The kit comes complete with slightly smaller slotted and cross-drilled rotors, redesigned caliper brackets, ABS sensor brackets, and all the necessary hardware. Performance Solutions in Boise, Idaho, performed this brake swap on a customer's '06 GT, and within a couple of hours, it was ready for the strip.
Horse Sense: JMS Chip & Performance obviously knows a thing or two about tuning, but the company also sells and installs hard parts as well. In fact they offer a number of performance packages that include mechanical and tuning upgrades for a variety of 'Stangs ranging from V-6s all the way up to Shelby GT500s.
Once the car is safely on...
Once the car is safely on jackstands or a hoist, the wheels come off and the calipers are removed. They will safely hang out of the way, so disconnecting the fluid line is unnecessary.
Then the caliper bracket is...
Then the caliper bracket is unbolted and put to the side. Although not shown here, the rear ABS sensors will be unbolted at this point to allow the axles to slide in.
Since the axles have to come...
Since the axles have to come out, the differential cover must be pulled, so the factory Panhard rod is unbolted to gain the necessary access.
The cover pops off and fluid...
The cover pops off and fluid is drained.
Remove the 8mm retaining pin,...
Remove the 8mm retaining pin, and the axle center pin will slide out easily...
...allowing the axles to be...
...allowing the axles to be pushed in and the C-clips to come out. Pretty easy so far, huh?
Unbolt the rotor shield. This...
Unbolt the rotor shield. This will not be reused.
The new caliper mount bolts...
The new caliper mount bolts on using the original hardware with a drop of thread-locking compound.
And the ABS sensor bracket...
And the ABS sensor bracket supplied by JMS will attach to the rear. Ensure that both brackets are seated properly on the housing flange.
All that's left is to reinstall...
All that's left is to reinstall the axles...
...and slide in the C-cli...
...and slide in the C-clips...
...and axle center pin.
The ABS sensor is bolted onto...
The ABS sensor is bolted onto the new rear bracket.
The shiny new rotors slip...
The shiny new rotors slip on. They are directional, so make sure they go on the correct side.
A fresh bead of silicone sealer...
A fresh bead of silicone sealer on the rear cover, and it's ready to slap on.
Then reinstall the calipe...
Then reinstall the caliper...
...housing bracket and......
...housing bracket and...
...caliper onto the new r...
...caliper onto the new rotors.
Bolt up the Panhard bar, and fill the differential with fresh gear oil and friction modifier, and you're all done. The 15-inch wheels fit with a quarter-inch to spare between the caliper and wheel. They fit well and look awesome. This thing is ready to cut some serious 60-foot times!