More Brake Fun & a Question

[RockyTop]

As you may recall I tried moving my stock front calipers to the rear to get more braking power, but the combination with the Alcon 4 piston front calipers provided too much rear braking force. In my quest to try every braking band aid short of breaking down (pun intended) and purchasing a full system, I am going to try the 2001-02 ABS rear caliper (which is suposedly larger than my 97 stock rear). Does anyone know whether (i) the 2001-02 caliper will bolt up to the stock 97 rear hubs without modification;(ii) as I have 17" wheels, are the 2001-002 rotors the same size as the 1997 rotors; and (iii) will there be adequate clearance ? The last question may be moot as I do have a 1/2 inch spacers and longer studs if needed (thanks again to John Purner).

This idea was provided to me by Erik Messley, who has been very gracious in providing me shock, spring, brake and other advice. Erik is just another reason this club ROCKS !

 

[Chuck 98 RT/10]

Sounds like you're going through a lot of R&D that has already been done by many before you. Save time and headaches and contact StopTech, Roe or Dilusi.

I'm considering the Porsche setup. I hear the pads are an inch thick and last forever, along with the rotor.

 

[Tom F&L GoR]

I tried this for my '94, and here's the problems:

1) The new caliper has a boss at the highest part that will perhaps interfere with the inside of the 17" wheel. You can grind it off... but

2) Then the brake hose end (attaches next to the boss you just ground off) will then be the highest part and you can't grind that off... so

3) you can relocate the brake hose to the unused boss for the bleeder screw. The calipers are cast to work on either left or right side, and only the higher located boss is drilled and tapped. You could tap the unused, lower one for the hose... and

4) then you'll have to disassemble it to clean it. But

5) The new caliper is only $90, but there is an additional bracket that holds the caliper and pads in place. The cost for the bracket is $500... per side. I didn't get that far to see if the bracket bolts to the stock upright. It might be close, but for the material cost and fiddling and machining, there are other ways to get better rear brakes. I'm still game, so if someone has other information, please let me know.

There are other 40 to 45 mm diameter single piston rear calipers with included parking brake... such as certain Corvettes, Camaros, and pieces from "restoration" places that make disc brake conversion kits for old drum brake cars. But without having one in front of me, it's hard to get enough information to know if the particular caliper is in the ballpark or not.

Let me finish by adding that I'm not looking for LeMans endurance rear calipers, just a unit that balances the front to rear braking performance for more rear braking. I mostly autocross, some time trials, and it's my everyday car, so it's mainly the balance I am looking for.

 

[Joe Dozzo]

Hey Rocky,

Your signature suggests you have an adjustable proportioning valve - I assume this is a replacement for the stock unit?

If you are getting too much rear brake action with your current caliper / rotor / pad setup, I would have thought cranking down on the proportioning valve (i.e. less volume and pressure to the rear) would have been the ticket.

We seem to have pretty similar setups (I have 6 piston Baer in front with stock fronts now in back). I opted to go one fairly big step further and added Snake Brakes ABS retrofit. Solves the F/R brake balance and the car stops like no other 3400 lb car I've ever owned - all day long!

 

[GTS Dean]

Joe,

Rocky's problem is that the piston area ratios from front to back are too close to 50/50. He has the 4-piston fronts instead of your 6-puck units and there is too much rear bias for even an adjustable prop valve to take care of. One of our other respected racers sold him something that didn't have a snowball's chance in you-know-where of working properly and he doesn't want to buy another set of new Alcons for the front.