Suggestions for an "OEM Looking" or "Period Correct" Rear Caliper Upgrade

I‘m looking to upgrade the rear calipers. I could change discs and hats if necessary, but would much favour a setup that retains the oem discs and hats. The calipers should mount without brackets, look more or less period correct, not have markings that would blatantly identify them as not oem and preferably be oem on a car. In other words shouldn’t be recognizable as „not oem“ by the untrained eye. I‘m not too keen on aftermarket suppliers. I’m open to suggestions for the handbrake. I know it‘s a tall order, but perhaps some of the more experienced and knowledgeable in the forum can help me out.

Thanks

Original Post

The previous owner of my Cat had aluminum hats made for his idea of making a GR3 replica. Selling everything as I want a big brake kit.

But what I want to show you is that he had no need for a bracket for the rear, just re-drilled the mounting holes.

He also used these Calipers with integrated handbrake.rearbracketora1

Hope this helps. Jochen

Attachments

Photos (2)

Your requirements pretty much restrict you to what you already have. The two-piston calipers shown in above posts are Gr-3 or Mangusta rear calipers, and pads for the pair-of-pliers style e-brake are hard to find; some say impossible. Girling made a number of these for other brands- FIAT, Aston-Martin, Rolls-Royce etc. GT-5 and GT-5S Panteras used a larger variant of the RR brake with a 1.25" thick vented rotors and enormous 3-piston iron calipers.

A few owners use two complete stock rear calipers on each stock upright, hooking up only one e-brake per side. This provides a stock appearing, bolt-on brake system with legal e-brake  that is better than pure-stock but extremely heavy. The stock non-adjustable proportioning valve will not be balanced with 4 rear calipers (actually, its not balanced with stock brakes and modern tires, either!) so should be discarded and brake plumbing reconfigured.

An option requiring machining is to adapt a Wilwood two-shoe drum e-brake that is built into the hat-section of the stock rotor. Early Corvettes also use such things. While not at all 'stock', the parts are completely hidden inside a modified rotor except for the actuating cable.

Stock '71-'76 Panteras had no separate 'hats' on their solid 0.875"-thick rotors. Vented 11.5" OD rotors from early 911 Porsches or some Volvos, with custom built spacers, will fit and markedly reduce weight; paint aluminum spacers black for a 'stock' look. There are some vented one piece late-'60s Mustang rotors - with no 'hats'- that bolt on but are extremely hard to find, as two-piece rotors supplanted the one-piece design several decades ago. Brake mods are serious business! There are a large number of pertinate articles in the POCA Club Archives on brake improvement (membership req'd for access).

Those calipers Jochen posted look to be BG Developments out of the UK, they remake classic and race calipers. The UK in general has some really nice aftermarket integrated and stand alone handbrake calipers that actually work as they have to hold against a rolling road resistance on annual inspection.

If it were me I'd keep the existing calipers and cap the hydraulics off as a parking brake only and add aftermarket calipers to the front side of the upright. Doing that without any adapters will be tough.

The more important factors to take into account are the overall braking system, you should use a brake system calculator that has inputs like master cylinder size, pedal ratio, disc and pad size, proportioning valve impact etc. to engineer a system or you can end up adding too large a caliper on the rear that will turn the car 180 degrees in heart beat.

Fortunately Scott at SACC Restorations (vendor banner at top of page) has done all that work for you and sells a rear brake only upgrade, so why try and reinvent stopping the wheel! You can always get caliper paint and black out the manufacturer name and no one will notice when you are cruising down the Autobahn, but you will be able to stop should the sudden need arise!

eugenioinnocenti posted:

Would love to hear comments on the  2 Willwood kits.  6 piston caliper upgrade for the rear and the kit including the 4 piston caliper upgrade front and rear including 12.19 x 1.25 rotors. You can PM if you prefer.

Thanks

#6018 is equipped with older Wilwood "Superlite" brakes. The disks 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.

#6018 brakes with no nose dive or tail lift, that's at any speed including triple digits. And it brakes hard, stops in very short distances! 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 have all the stopping power your street Pantera needs.

Its an aluminum Ford SVO master, I suspect it was original equipment on some SVO Mustang. Some day I may take it apart, but haven't yet. So I haven't had an opportunity to measure the bore size. We've discussed this master in past threads, you may try a search. I can't remember if we've ever determined a part number. I'm getting to that age where my memory doesn't serve me as well as it once did. If I had to place a wager, I'd bet that the brakes & master were originally sourced from Dennis Quella, you might give him a call. Or give Scott Bell (SACC) a call ... he'll have a recommendation for you.

The brakes are at least 20 years old, the master may not even be available now. Frankly I think anything close to the OEM size will be fine.  If you can't find an off the shelf master, why not use a Wilwood master? They make a nice one.

Sorry I couldn't be more helpful.

Add Reply

Likes (0)
×
×
×
×