Lightest Brakes

[Randy Webb]

What are the lightest brakes I can put on a 1973? It's a street car, so I'd like to reduce unsprung wt. rather than put soem gigantic heavy brakes on to dissapate heat that will probably never be much of a factor. The car has Carrera calipers on it now -- I don't know what rotors are on.

I know some people have backdated to the Al "S" calipers. I've also heard that some people have used the REAR calipers from the 951 (944 turbo).


Thanks.

[masraum]

I have heard that the Al S calipers will work with Carrera rotors, but I don't know how certain this is. I think that would be the lightest you could get.

[Bill Verburg]

Monobloks w/ carbon/ceramic rotors only costs about $15,000

[Randy Webb]

Gee, Bill, Thanks! Carbon isn't good on a street car anyway, right?

I do hope to live long enough for ceramic brakes to fall into the $2,000 range and be made for the early cars.... If not then I expect my car to live long enough for someone hwo is just being born now to continue fixing it up over the next century.

[911pcars]

According to Jim Calzia's research (http://www.early911sregistry.org/jcalziaweights-2.htm), the S calipers and the 944 Turbo calipers weigh about the same (6-7 lbs.). The carrera rotors will add a little more weight since they're 3mm thicker.

The lightest setup, except for you guys with carbon-carbon brake budgets, would be the factory "S"/"RS" setup, S calipers with 21mm rotors.

Sherwood Lee
http://members.rennlist.org/911pcars

[Randy Webb]

Hmmm, maybe the question I ought to ask is how much the Carrera calipers weigh? Maybe I won't save much by going to "S" calipers?

[Bill Verburg]

Now we're getting somewhere. Sherwoods answer of the stock S calipers and rotors front and M caliper and rotor rear is of course the lightest(unless you want to backdate to the old solid rotors w/ M fronts and L rears). It is also the most appropriate for most people most of the time, that's why the Porsche engineers used them. But there are always those that push the envelope. Every up grade is heavier because every upgrade relies on mass to enhance thermal properties. All upgrades derive their primary benefits from increased rotor mass. the calipers are just there to accomodate the rotor.

Here are some weights of some others
A caliper 11# w/ pads & hardline
M caliper 8# w/ pads & hardline
965rear cal 8# w/ pads, cal 6.5#, pads 1.5#
S4 front 9.25#w/pads
Bigred 10.25# w/pads

It's not the calipers that are heavy it's the rotors The 930 rotors are almost 2x as heavy as the 911s, the 322x32 is another 5# ea. You do make some savings w/ 2 piece rotors. If you are toasting your brakes any weight penalty is justifiable.

Jim used NLA al. metal matrix rotors in an effort to get the thermal properties of 930 rotors w/o the weight penalty, they didn't pan out

[Eric Coffey]

Don't the AL "S" calipers use thicker pads too?

[Bill Verburg]

"Don't the AL "S" calipers use thicker pads too?"

Depends on the manufacturer. Some S and A pads are interchangeable some are not.

[Chuck Moreland]

Bill,

What more do you know about these aluminum matrix rotors. Who, what when? and why didn't they pan out for Jim?

[Bill Verburg]

The aluminum metal matrix were a great idea that didn't work out. There were problems with friction characteristics and durability. Currently there is an effort to do the same thing w/ Ti in a metal matrix rotor. Haven't heard anything on them yet.

The best that can be done currently is to use the 2 piece w/ al. hats.

[Randy Webb]

Bill, Where does one get the 2 peice rotors with Al hats? And how much do they weigh if you know?

Also, what is the 965rear cal and the S4 that you posted about above?

Thx, - Randy

[TimT]

For a lightweight, less expensive alternative try Wilwood , you could use the billet 6 pot calipers up front, and the billet 4 pot calipers in the rear.

I think the 6 pot calipers are about 325 each. Wilwood can also make hats anbd rotors for you if you dimension and spec out what you need.

p.s. Wilwood is used by some of those Nascar tanks....along with alcon.