Brake upgrade for early 911

carreraplanes · 06-23-2005, 06:54 AM

Q. What simple changes can I make to improve my early ('73)brakes? They are 'S' spec ali. calipers. I don't mean the 'go to the tuning shop and buy a 66 pot brembo type solution'. The pads are standard fit as far as I know. I was thinking of uprating the pads and seeing what it was like then. Does anybody recommend a particular pad for fast road use? If that does not prove to be adequate (as would probably be the case) I would uprate the calipers. I think the early 930 Turbos used 917 style calipers as did the 2.8 RSR. That would mean a set of early turbo calipers would be in keeping with the car if they could be mounted to the axle stubs whilst clearing the 7s and 8s. Anybody have a view on this please?

pwd72s · 06-23-2005, 09:31 AM

Search and ye shall find...there have been lengthy threads on this topic here.

RoninLB · 06-23-2005, 10:23 AM

Quote:

Originally posted by carreraplanes

Does anybody recommend a particular pad for fast road use?

does this mean your pads are cold when applied ?

carreraplanes · 06-23-2005, 11:19 AM

I warm the car up fairly slowly from cold and really do not start to press on until the car is thoroughly warmed through after 8 + miles.

randywebb · 06-23-2005, 11:30 AM

You need to define "simple" and "improve"

What problems are you having?

Carrera calipers will fit the S type mounts.

And -- if "improve" means Maximum Bling Power, then I would go for the 50 lb., 25 piston, Glow in the Dark Neon brake kit. GreaseBall's Garage has it - as well as the shiny Chrome-plated rotor option.

Seriously - the bling factor is an ever present contaminant in upgrades - watch out.

RoninLB · 06-23-2005, 11:31 AM

Quote:

Originally posted by carreraplanes

I warm the car up fairly slowly

I meant the brake pads.

in other words do you occasionally use your brakes as in routine highway driving and are disappointed? or are you disappointed on mountain twisties with warmed up brake pads?

tobluforu · tobluforu's Garage

I have a 72 and "use" to auto-cross the car and bring it to sears point and such for NASA events. The brakes on these old cars are pretty good for just having a little fun. Not good for racing. I put ferodo pads and vented rotors on my car with an updated master cylinder and it works fine for what I do. My car is also very light, one seat, fiberglass bumpers, blah..... so it stops pretty damn good. Unless your going to track the car, I would do what I did or a form there of. Drain all the brake fluid, "maybe" get a new master, some good pads (seat them right) and maybe vented rotors(lots of speculation on these as well).
Have fun.
Oh yeah, don't forget to paint calipers the same color of your car-much better stopping power.

Bill Verburg · Bill Verburg's Garage

The brakes don't warm up unless you use them long and hard.

Sounds to me like a normal street type pad that worrks well when cool to luke warm.

Good choices

PBR metal master
Pagid Blue
Ferodo 2500
textar yellow box
PFC carbon metalic
Jurid
Hawk HPS

Bill Verburg · Bill Verburg's Garage

Oh and if you don't know how warm the brakes are, try using some temp paint

randywebb · 06-23-2005, 12:49 PM

temp paint can be had at Omega Instruments, if not locally

- What pads are in there now?

Back to the problems you were having....

some claim the Al calipers 'flex' -- do you feel that?

Fade?

carreraplanes · 06-23-2005, 03:13 PM

Quote:

You need to define "simple" and "improve"

What problems are you having?

Carrera calipers will fit the S type mounts.

And -- if "improve" means Maximum Bling Power, then I would go for the 50 lb., 25 piston, Glow in the Dark Neon brake kit. GreaseBall's Garage has it - as well as the shiny Chrome-plated rotor option.

Seriously - the bling factor is an ever present contaminant in upgrades - watch out.

Couldn't agree more. In fact bling factor is common in all areas of upgrade (wheels, tyres, brakes, induction, exhaust, you name it)on many different types of car. The truth of it is that a very high number of these mods actually slow cars down over bog standard spec. Bling is not a factor here in fact I'm reluctant to change things too much as I like original looking cars even if what's under the surface is a bit special.

Quote:

I meant the brake pads.

in other words do you occasionally use your brakes as in routine highway driving and are disappointed? or are you disappointed on mountain twisties with warmed up brake pads?

Definitely twisty road driven hard syndrome. I have heard it said elsewhere that the early brakes with ali calipers work ok if you push really hard. This seems to be the problem. Push like hell and they are just that - OK. By virtue of being without a servo I guess. For family driving to the shops they are more than adequate. For fast driving on twisty, uncrowded back roads just OK. It means I am having to brake much earlier than I would normally expect to in a performance car. My previous 911 was an SC and this was quite the opposite. First 911 model to be fitted with a servo? That if anything was over braked with a tendency to lock the fronts if you were any less than super smooth under heavy braking (something that was sorted with a brake bias valve on the later 3.2 cars). It taught me the principles of threshold braking which helped me through sprinting the 911 (a timed run on a closed road, or 1 lap of a race track) and a couple of seasons of saloon (G 40 Polo) car racing.

So I use the car for hard driving on country roads where the brakes have a chance to warm up but I also plan to use it for sprinting where the brakes need to be fairly instant from cold. Perhaps I would need to change the pads when doing competition work.

Quote:

I have a 72 and "use" to auto-cross the car and bring it to sears point and such for NASA events. The brakes on these old cars are pretty good for just having a little fun. Not good for racing. I put ferodo pads and vented rotors on my car with an updated master cylinder and it works fine for what I do. My car is also very light, one seat, fiberglass bumpers, blah..... so it stops pretty damn good. Unless your going to track the car, I would do what I did or a form there of. Drain all the brake fluid, "maybe" get a new master, some good pads (seat them right) and maybe vented rotors(lots of speculation on these as well).
Have fun.

My car has vented discs. Pads are standard. I think your strategy sounds to be at about the level that I would pitch my first attempt (Turbo calipers are quite a costly mod and might be a little over the top, still unsure as to whether they would fit under the 15" rims anyway). What is the updated master that you use? And what spec Ferodo? With your auto X events do you warm the brakes over the course or just hit the pedal from cold?

The early 930 turbos apparently used the calipers that I have. I wonder if those cars used the same master cylinder or an upgrade to deal with the extra weight and performance?

Thanks to you all for your interest

randywebb · 06-23-2005, 03:19 PM

Given what you already have, I'd first try the 993 air deflection shields; and if you need more (or are not going fast enough to get much air) then you'll have to go with Carrera calipers or something else. How wide are your rotors?

And... are the calipers in good shape internally?

Bill Verburg · Bill Verburg's Garage

Sounds to me that you will just need to learn how to push harder.

You have a lighter car with exactly the same spec brakes as on your SC, except they are not boosted and the front caliper is aluminum. Neither makes much difference in your situation. It's hard to imagine an early car pushed to the limits of it's brakes in this country on public roads.

An early RS w/ your brakes will not experience brake related troubles on track.

randywebb · 06-23-2005, 08:32 PM

Actually, he's in the UK -- so the Calif. heat wave and twisty uphil/dnhill road experience does not apply.

Do you feel like the pedal effor has gotten harder over time?

Or if the car is new to you, what are you used to driving?

Rod.911S · Rod.911S's Garage

There's an article in the June '05 issue of Panorama that says "adding larger brakes will not necessarily stop the car faster...since a well maintained Porsche will probably stop no faster... since the brakes are plenty adequate to lock up the wheels already, at least from several stops made sequentially from high speed."

"The only ways to make your Porsche stop faster are to lower the car's center of gravity, fit higher coefficient large contact patch tires, lower the car's weight and make sure the brake bias is optimized, not fitting larger brakes."

"This point may be particularly applicable to autocross where adding the rotating, unsprung weight of a larger brake system is usually of no advantage."

Makes sense to me.

YMMV,

304065 · 06-24-2005, 06:11 AM

I have a '71E with the S package- aluminum S calipers, iron M's, SS lines, pagid Orange, Castrol SRF. No ducts, scoops, or that stuff.

No problems. No fade. No overheat. (No checkered flag, though!)

As Bill V posted elsewhere, the tires are often the limiting factor, not the brake torque.

Bring your stock system up to "S" specs with some Pagid Blues for the street and see if that works. Big Brembos both increase unsprung weight (not good) and decrease cash level (not good) and make you run larger wheels besides.