Brakes Again

[Matt_West]

The car is a 1980 sc, which is getting slowly lighter. So far deleted aircon, wevo battery box, ditched spare, tools, and jack. Nothing too radical yet, but headed in the right direction.

So in reading Teo's thread, some people stated that they were thinking about reverting to the SC brakes...

If the SC brakes are being deemed acceptable then are the Boxster monoblocks being viewed as more than a cosmetic upgrade these days?

Here is my thinking:

My calipers will need rebuilding the next time I do pads. Would I not do better to switch to lighter calipers, that do not transfer heat as effectively, offer more pad area, and apply pressure more evenly, while getting slightly larger rotors?

[Eagledriver]

There are a wide variety of opinions on brakes. If you are not racing then your SC brakes may be enough. Ducting air to the fronts will help alot with keeping the calipers from leaking and keeping the fluid from boiling. What makes you think the fronts need rebuilding? My Carrera calipers on my race car have never been rebuilt and they have 5 seasons of racing and are 19 years old. I've seen lots of people have problems after rebuiding calipers with the new seals failing.

-Andy

[Bill Verburg]

If the SC brakes are being deemed acceptable then are the Boxster monoblocks being viewed as more than a cosmetic upgrade these days?

No!
rotors are the component to concentrate on, anything that keeps rotor temps down is the goal.

Some things that are steps in the right direction

• cool air
• less weight
• not using the brake as often
• keeping speed D to a minimum
• longer rest periods between applications
• bigger rotors
• rotor w/ enhanced internal flow
• more open face wheels
• wheels designed to pump air across rotors
  

[JeremyD]

Upgrade the calipers for show - the rotors for true stopping power and heat disapation.

[Todd Simpson]

The Boxster upgrade is an upgrade in your case because it brings 24mm rotors compared to your 20mm.

You could get the same benefit by using carrera rotors and calipers, though the Boxster calipers are lighter than the carreras.

What do you plan for the rear? Have you calculated bias?

[Blanco]

The ultimate brake upgrade page.

[deoxford]

Carrera Brakes will let you move up to the 24mm Rotors, that is all you need

[arrivederci]

Here's what I doing. Hopefully it'll be enough for the thin air and hot track temps we get.

• cool air
  -AJ ducts + blockoff plates + 993 diverters + RSR/IROC front bumper?
• less weight
  -shooting for under 2000 lbs
• bigger rotors
  -24mm carreras
  

This is a relatively inexpensive upgrade over the '72 S calipers and stock 20mm rotors that I have. My biggest issue with my current brake setup is the spongy feel of the S calipers. I have a DE next week where I'll probably know for sure if I'm running out of brake with my 20mm rotors.

There are two keys for my application.

1) Increase thermal reserve without a drastic increase in the weight of the brake package. There's no need to put 'bling' brakes on a lightweight car.

2) Fit in 15" wheels. The vintage racing class I'm building for allows a maximum of 15x8 rims.

[Bill Verburg]

Josh, the sponginess you feel is in all likelyhood the caliper flexing, the Carrera calipers will fix that.

[911-32]

While I agree pretty much with the tech analysis already given, I think if faced with the choice of new 3.2 calipers or Boxster calipers (both over 24mm rotors) I would be sorely tempted to go Boxster. Sure its a little bling, but you do get the lighter, stiffer caliper with bigger pads. Since changing to 964 front brakes on my 3.2 the pads last close to 3 times as long. I also think the 3.2 calipers flex pretty much like the SC calipers.

There are also a number of 3.2 owners (particularly a couple of CSs) who swear that the Boxster caliper alone over std rotors has made a quantifiable difference to both measured braking distances and rotor temps. These are either serious track junkies or racers (the two CS guys anyhow). The science says otherwise but some of the anecdotal evidence is actually pretty compelling.

HTH
Richard

[Bill Verburg]

No one ever said that there is much difference between wide A and Boxster calipers on the 24mm rotors, the caliper may be stiffer(that is debatable as well but we'll leave that) but the extra adaptor allows for some additional flex as well. the only knock was the relative cost of the 2 duifferent setups. i.e. bang for the buck

Yes, an advantage of a bigger pad is to spread the thermal an mechanical loads over a larger area, this does reduce the mech. and thrm. point loads and extends the life of that component. At the expense of increased rotor wear(again a little)

It does not and cannot increase the brake torque except to the extent that the piston area is slightly(but not much,) different

There are also a number of 3.2 owners (particularly a couple of CSs) who swear that the Boxster caliper alone over std rotors has made a quantifiable difference to both measured braking distances and rotor temps

keep thinking good thoughts and it will be so