The rear brakes of the S197...
The rear brakes of the S197 Mustang limit wheel size since smaller wheels won't clear the stock calipers. With JMS Chip and Performance's 15-inch brake kit, running 15-inch rear wheels is no problem.
It's common knowledge that S197 Mustangs are capable of tremendous horsepower. With 700-rwhp GTs becoming a daily occurrence, getting those ponies to the ground is now a struggle, to say the least. Though the overall suspension design of the S197 works and responds well to upgrades, getting big power to the ground isn't possible without the right tires.
Even though huge advancements in tire technology have taken place in the past 20 years and tire companies now offer some of the softest compounds ever available in 16-, 17-, and 18-inch variants, without the ability to fit a smaller diameter wheel around the factory brakes, sidewall height is still limited. Having extra sidewall is necessary to absorb the hit of a drag racing launch, plus most slicks are offered in the popular 15-inch wheel size.
The kit from JMS is simple...
The kit from JMS is simple to install and includes two SN-95 rotors, two laser-cut 3/8-inch caliper brackets, two 1/4-inch laser-cut wheel-speed sensor brackets, and all the associated hardware and instructions.
JMS Chip and Performance now offers a brake kit to fit 15-inch wheels on any S197 (V-6, GT, and GT500). This kit comes with coated, crossdrilled SN-95 rotors; caliper-relocation brackets; wheel-speed-sensor relocation brackets; mounting hardware; and detailed instructions. All of the brackets are laser-cut from mild steel and powdercoated for a super-clean look.
"S197 owners can now take advantage of the various drag radial and slick sizes available for 15-inch wheels," explains Monty Johnson of JMS Chip and Performance. "You can now run a tire with enough sidewall to get even the highest-horsepower S197s down the street or track." Once the kit is installed, most 15-inch wheels will fit, and backspacing can be determined based on how wide of a wheel you plan on running.
Follow along as Roy Snelgrove shows us the finer points of installing JMS Chip and Performance's 15-inch brake upgrade for the S197 Mustang.
The stock calipers don't change...
The stock calipers don't change with the kit. The rotors and brackets, on the other hand, will be replaced.
The JMS kit uses a 10.5-inch...
The JMS kit uses a 10.5-inch SN-95 rear rotor instead of the 11.8-inch S197 unit.
After removing the stock calipers...
After removing the stock calipers and brackets, remove the factory wheel-speed sensor bracket. This will be replaced later in the installation.
Next, Snelgrove removes the...
Next, Snelgrove removes the differential cover and carrier pin. Once the pin is out, the C-clips are removed and the axles slide out.
With the axles out of the...
With the axles out of the way, Snelgrove unbolts the factory dust shields and caliper brackets.
The new caliper bracket simply...
The new caliper bracket simply bolts onto the inside of the factory flanges on the rearend housing. The new bracket moves the caliper inward to accommodate the deeper SN-95 rotor. The smaller-diameter rotors use the stock S197 calipers, and the brake-pad contact patch on the rotor is unchanged.
Next, the new wheel-speed-sensor...
Next, the new wheel-speed-sensor bracket is installed. This also uses one of the holes in the flange as an attachment point.
After the bolts are torqued,...
After the bolts are torqued, the axles are reinstalled and the differential is reassembled.
The wheel-speed sensor is...
The wheel-speed sensor is reinstalled in the new bracket. The contact area of the sensor is still more than enough for an accurate reading.
The caliper mount is then...
The caliper mount is then bolted back onto the new caliper bracket and the caliper is reinstalled.
The finished product is a...
The finished product is a clean factory look with....
....plenty of clearance for...
....plenty of clearance for 15-inch drag wheels.