I have the tall B-body spindles on both my cars. The 12" rotor under a 15" wheel is nice. One car has stock calipers and stops well. The other has aluminum Willwood single piston type 3 I think calipers and that car also has Camaro rear discs and a Master Power dual diaphram booster and a disc/disc master cylinder. It doesn't stop worth a darn.

Are there any PBR or Vette or Musatng calipers that would work with that rotor and spindle if I made a braket?

What do you guys think. Both cars have adjustable prop valves as well.

I don't think you'll get any kind of Vette/Mustang/PBR caliper under a 15" wheel - it would probably even be tight with 11" discs and even then, wouldn't be worth the effort. As you already know, it's possible to stop just fine with the stock calipers. On your other car, it sounds like you may have a master bore sizing issue - or the rear calipers are sized wrong for the whole system. From what I've read, many people have this problem running 4-wheel disc brakes.

What year Camaro rear discs are you running? Late 70's (2nd Gen)?

Ryan

2nd gen rear discs. I think 10-11". The other car has rebuilt drums in the rear and it will damn near put you through the windsheild. In the wagon I can't even brake torque due to the lousy brakes. It pushes right through it. I have had a couple of master cyls on it and I think I'm running a Vette one now with 1" or 7/8" bore.

I was thinking the twin piston calipers from a 3rd gen Camaro or SN95 Mustang. But your proabaly right about it not fitting under the wheels.

Just curious. What about the Force 10 SuperTwin HD 2-piston aluminum calipers from Stainless Steel Brakes Corporation (SSBC)?

Why not try these;

http://www.stockcarproducts.com/outlaw.htm

They'd look custom but really just be stock.

Peter

Whittaker,
I went thru a lot of trials in doing a very similiar setup to yours on my 71 SS. I put 12" rotors in fromt and the 11" TA rear disks in the back. I could not get good feel or stopping with the stock setup. I knew I was low on vacuum, so I chose to go manual brakes. I got a Corvette manual 4-wheel disk MC and that helped, but was still real hard. I tried the small, dual-diaphram booster, but then found out they actually need a lot MORE vacuum to operate correctly than the larger single diaphram ones. It is recommended that you have at least 15" of vacuum to run one of those. I tried various other MCs and finally settled on the Corvette 4-wheel disk manual MC. I turned to looking at the calipers as possibly the problem...

In investigating the claipers, I found out that the newer PBR style multi-piston calipers do not have as much surface area as the stock single piston calipers. This means that they do not transfer the pressure as well as the single piston calipers do. More surface area means more pressure out for a given pressure in. What I found out is that the PBR style calipers are actually designed to be used on systems that have braking pressures nearly DOUBLE of what the stock disk brake system generates. What that means is that with a stock MC and the PBR calipers, you have to push the pedal real hard to generate enough pressure to properly operate the calipers. By comparison, if you were to dissect say a 2000 Camaro brake system, you would find that it has a power disk brake system that has an MC with very small (about 7/8" diameter) piston bore. It also will have the multi-piston calipers. These calipers have much less surface area, so they require much less fluid to operate and therefore, the MC bore size can be quite a bit smaller. Smaller MC piston bore means more pressure! By comparison, the old, stock, single piston calipers take as much as 900 psi braking pressure to operate fully. The newer calipers can take upwards of 1,600 psi to fully operate!

I actually found some late 70's thu mid 80's suburban calipers that had a bigger single piston in them. They bolt right up to the stock single piston caliper mounts and will provide more output pressure for the same input pressure. These helped pedal feel quite a bit.

For your applications, on the stock caliper car, I'd recommend trying the Suburban calipers and seeing how they feel. I know you said they work good now, but believe me, there is always room for more improvement! If you want to try manual brakes on that car, you could try a MC from a 77 Malibu 6cyl, manual brake car. That MC has a small 15/16" piston bore and will make good pressure. The reservoirs are flopped, so mind that if you try.

For the car with Wilwood calipers, can you measure the vacuum of the motor? Since it has the smaller booster, it will need quite a bit of vacuum. If you think you might not have enough vacuum, i.e. it's under 15", then you might try simply removing the booster and trying the MC you have. The dual-diaphram boosters are really hard to push if you don't have the right vacuum, so you might find the pedal easier to push with it out with the same MC. If not, I'd try the Corvette 4-wheel disk brake MANUAL MC to see how that feels. If pedal feel is still pretty firm, but pretty high, you could try the Malibu MC listed above, but it may not have enough volume to make the prakes work correctly before you run out of pedal travel.

Anyway, sorry for being long winded, hope that helped a little.

Good luck,
Bill C.