wanting to run 13" rotors and wilwood calipers

I'm wanting to run 13" rotors and 4 piston wilwood calipers, and would like to get some feedback from others who are running this type of setup.  I have been looking at SACC Pantera Performance Plus Brake Kit (4-13 front 4-13 rear) and am curious if anyone is running this kit, pros and cons, ease of installation. Any info would be appreciated

Original Post

#6018 is equipped with older Wilwood "Superlite" brakes. 12.75 inch diameter disks which are 1-1/4" thick (racing disks). These expensive brakes are part of the reason why I chose to purchase this car.

The disks are the same diameter at all four corners. The calipers have 4 pistons at all four corners. The pads are the same dimensions at all four corners. There's no proportioning valve. The braking has been balanced by varying the front & rear caliper piston diameters. The front pistons are 1-3/4 inch diameter, the rear pistons are 1-3/8 inch diameter. The calipers are mounted towards the middle of the car; front calipers are mounted behind the axle, the rear calipers are mounted in front of the axle.

The way these brakes are configured makes it easy to calculate how the braking force is balanced front to rear. The rear pistons have 62% of the area (braking force) of the front pistons.

#6018 brakes with no nose dive or tail lift, that's at any speed including triple digits. And it brakes hard, stops on a dime! Those experiences occurred while the car was equipped with 245/40ZR17 front tires.

If you think you might ever want to return to using 15 inch wheels on your Pantera, you should consider 12.19 inch diameter disks; the largest disks that will fit within 15" wheels. 12.19 inch disks with 4 piston calipers were standard equipment of the Group 4 Panteras, and were once standard equipment on Indy Racing cars too … they'll stop your street Pantera in short distances.

Scott (SACC Restorations) is on top of the braking situation.

Keep in mind that  you already have 11"+ OD discs and four-piston calipers (in front) as stock, so adding slightly bigger OD rotors of the same thickness gains nothing except weight, unless you remount new (or old ) calipers outboard  to take advantage of the new rotor's extra area. Stock mount pad positions will not touch the added OD of big rotors so no leverage gain. DYI redrilling and tapping a new caliper mount pattern is not as simple as it sounds either, as the stock metric caliper mounting bolts thread into the stock forged steel steering arms. So, many kits use some sort of adapter bracket, which usually need shimming to center the opposing pistons. Shims should be included with the kit. If your area of the country has yearly road- worthiness inspections, there's the parking brake situation to consider...

That said, some Wilwood front calipers fit if you tap a third hole in the steering arms, but if you use an existing hole to make the adaption simpler, the spacing Wilwood uses pushes your new 2nd hole VERY close to the end of the steering arm. Being steel, you can do this, then gas-or-arc-weld a blob of new steel on the steering arm end where the new hole nearly falls through the forging, for safety. Smooth the weld off with a file and paint to look stock, then tap metric as req'd. Using (stock) gr-5 metric  bolts means drilling your new Wilwood mount lugs oversize. SAE Gr-8 bolts fit the calipers but not the stock holes. I did all this to a pair of Wilwood Superlite 2 frt calipers some decades ago, for autocrossing with 11.5" OD adapted Porsche vented rotors, and no further problems. They are manually valve-balanced & will lock 245-50 front tires at any speed in a max-effort stop.

Note these are the widest tires that will fit uncut front narrow-body fenders, regardless if they're 15", 16", 17" or 18" OD tires. If you need more brake than this, you must be currently racing in a pro class & don't need this advice. If you simply want bigger brakes, that's a whole 'nother subject. Go for it!

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