The Problem
Slipping and sliding is now...
Slipping and sliding is now a thing of the past. And we look good, too, thanks to Ford Racing Performance Parts and Discount Tire.
Let's face it, Fox-body 5L Mustangs have never been known for their stopping prowess. Ten and a half inch rotors up front and 9-inch drums out back just don't cut it in today's world of anti-lock, four-wheel disc braking. And if you have brought your pony to ultra-modern power levels, like we have, you're not only under the gun, you're under the firing squad!
Since supercharging our '90 GT with ProCharger's P-1SC huffer, our horse gained 130-plus rear-wheel horsepower and is hauling its tail like never before. Stopping the pony was a problem prior to the power enhancement, and so we looked to Ford Racing to provide a remedy.
The Solution
In the heart of the Ford Racing Performance Parts (FRPP) catalog, one will find the five-Lug Front/Rear Super Heavy-Duty Cobra Disc Brake Conversion Kit, otherwise known as PNM-2300-K. We went to FRPP for improved braking mainly because it uses all factory equipment. If we need to do a brake job, all we have to do is pay a visit to our local parts store for replacement rotors or pads. We also took into consideration the extensive testing these parts are subjected to before they go on a production vehicle.
The kit is quite inclusive, providing everything you need to convert your failing Fox braking system into a stalwart stopper. Starting at the rear is a new set of 11.65-inch rotors and calipers, new axle shafts, brake lines and hoses. Four parking brake cables are supplied, as two are for '87-92 Mustangs, and the other two are for '93 models. Moving forward, giant 13-inch rotors and Cobra-embossed calipers really toss the anchor out when you step on the negative-G pedal, and new spindles with sealed-bearing hubs make changing rotors a snap. More brake hoses and lines are provided for the front brakes, and dust shields are supplied for all four corners. FRPP also includes a new master cylinder, brake booster, and an adjustable proportioning valve to ensure the four-wheel discs perform at their peak.
We did mention the M-2300-K kit is a five-lug system. This requires a new set of wheels if you haven't already added the additional lug studs. Having the 13-inch rotors up front will also affect your wheel choice; with whatever wheel you choose needing the appropriate backspacing and clearance for the calipers. FRPP recommends a 17x8-inch wheel with a five-hole, 4.5-inch diameter mounting pattern, and 5.75-inch backspacing. This makes things very easy, as many of the factory Ford wheels already have this. Flipping through the FRPP catalog, we counted six different wheel styles that would work, and adding the '94-98 17x8-inch GT wheels would increase the number by two. So you have quite a few wheel choices without even going to the aftermarket, which has an immense number of custom wheels available with that backspacing.
We had originally planned to go with some silver Bullitt-style wheels, but after talking with Dan Meadows at Discount Tire Direct, we opted for a set of Fittipaldi Force rims in a 17x8-inch size. The Fittipaldis are sold exclusively through Discount Tire and are available in 17x8-18x8.5-inch sizes. The Force rims featured a 35mm (5.85 inches) backspacing. Any more and we run the risk of contact with the front lower control arms. The wheels are machine cast and clearcoated for easy cleaning and a shiny finish, and once we checked them out on a Thunderbird in Discount Tire's gallery on its Web site, we knew they would give our pony a unique style and add a little pizzazz to the stock body.
 As you can see, there are...  As you can see, there are a lot of parts to be installed. The good thing is they all fit perfectly because they are factory issue parts. Check out the big, juicy rotors. That's what we're talking about. |  It's Christmas time at Eric's...  It's Christmas time at Eric's Performance! Here, Eric and Assistant Tech Editor John Hedenburg assess the various components. Hedenburg, our resident bracket racing maniac, assisted during the operation. |  Eric began by dismantling...  Eric began by dismantling the rear drum brake components. This included removing the drums, springs, and shoes. |
 In order to remove the stock...  In order to remove the stock axles and backing plates, the C-clips and carrier pin need to be removed from the differential. Then the axles slid out. |  Next, the brake lines were...  Next, the brake lines were disconnected and the backing plates were removed. |  The kit comes with new backing...  The kit comes with new backing plates for the calipers. They bolt on using the stock mounting points, and are supported by moan brackets that bolt to the axle tube. The dust shields can then be installed along with the new, longer axle shafts. The axles are the same 28-spline units found in the '94-98 Mustang. Should your future include sidestepping the clutch with slicks, you may want to use a stronger axle, but for our application, these slightly thicker stock shafts will do fine. |