School me about a brake upgrade please

[irl]

I have a 74 with stock everything brakes. If i upgrade to something better like S calipers, what upgrade do you recommend that wont be off the chart expensive and what else changes, rotors?,master cylinder?

Thanks,

[Bill Verburg]

Originally Posted by irl

I have a 74 with stock everything brakes. If i upgrade to something better like S calipers, what upgrade do you recommend that wont be off the chart expensive and what else changes, rotors?,master cylinder?

Thanks,

if you change to S calipers form M you first need to change the struts.

S and almost all upgrades will use 3.5" caliper mounts, M uses 3". The only 3" upgrade is a BMW caliper.

never go to a larger m/c unless you have changed to calipers w/ much larger caliper swept volume. All M, S & A setups use the same 19mm mc for unboosted aps and 20.6mm for boosted apps. When you go to 930/0964/993 calipers then you need the 23.8 or 25.4 mm m/c's

[Dr.Benzin]

S and almost all upgrades will use 3.5" caliper mounts, M uses 3". The only 3" upgrade is a BMW caliper.



Witch BMW has 3" caliper mounts who would be an upgrade on a old 911 with M calipers ?

[RWebb]

many "upgrades" are really downgrades

big brakes (unless you use ceramic rotors!) add wt. to your suspension - larger, heavier brakes are the last thing to do even if you change your system

are your brakes overheating?
- change your corner entry style
- duct air to the brakes
- lighten the car
- find a new track
- last, put heavier brakes on

[cfries]

I have the BMW upgrade. The mechanic in south Florida who put them on stated they were from a 7 series BMW, but couldnt remember what year. They work great on my '75 and were a direct bolt on. I havent replaced the pads yet, but when I do, I'll find out.

[Flieger]

Contact Eric Shea at PMB Performance. He restores and sells the 3" spacing Brembos. (the BMW caliper) They are a little lighter than the S caliper.

Brembo AM-Caliper: The "ULTIMATE" M-Caliper Up-Grade!!

[H-viken]

Originally Posted by RWebb

big brakes (unless you use ceramic rotors!) add wt. to your suspension - larger, heavier brakes are the last thing to do even if you change your system

Is there a site with weight comparisons between the different calipers and rotors?

[hesaputz]

Brakes

[Flying Toaster]

Does anyone know what year / model BMW had these calipers? TIA. -John

[Eric_Shea]

The only 3" upgrade is a BMW caliper.

Ya gotta stop saying that...

These are the best I've found.







Here's the low-down: These Brembos have a 3" bolt spacing and the exact same offset as the M-Caliper. This means they'll simply bolt right on. When I say bolt on I mean... all the way. They even fit with the standard dust shields. The fluid inlet is aimed right up at the tab on the strut for a direct in.

They have the same 48mm piston as the M-Caliper, S-Caliper and the later A-Caliper. What's cool about this is, they are the later "cup" type piston with no knock-back mechanism to deal with. The cup design offers better cooling with much more surface area than the standard M and S-Caliper pistons. Also nice is the fact that this won't throw off your fluid dynamics with your current Master Cylinder. Again, Bolt on!

The pad size is much larger than the M-Caliper pad. They are the same width as the A and S-Caliper pads but not as tall... (only slightly, like 2mm or so). If anyone is familiar with the BMW 320i pad size, these are the same. Another nicety, as I mentioned that these add up in all areas as a true bolt-on upgrade is; with this basic pad size (which has been proven with the S-Caliper and A-Caliper) there is no over stress of the standard 20mm rotor which obviously lived on all 911's through 1983.

They weigh in a full 4lbs lighter than the M-Caliper so there goes a good chunk of un-sprung weight (yes, they're aluminum!). Did I say "Bolt on upgrade!"?

You simply take your M-Calipers off and stick them on the shelf (in a plastic bag of course) for posterity sake, bolt these on, bleed the system (you know you should do that this year anyway) and you'd be good to go!

[winders]

Originally Posted by Bill Verburg

never go to a larger m/c unless you have changed to calipers w/ much larger caliper swept volume.

Isn't the real test for the master cylinder change the area change in pistons? You could go to a caliper with much larger pads ("larger caliper swept volume") yet have the same piston area.

Eric_Shea's post is a perfect example of what I am talking about.

Scott

[Bill Verburg]

Originally Posted by winders

Isn't the real test for the master cylinder change the area change in pistons? You could go to a caliper with much larger pads ("larger caliper swept volume") yet have the same piston area.

Eric_Shea's post is a perfect example of what I am talking about.

Scott

never go to a larger m/c unless you have changed to calipers w/ much larger caliper swept volume

that is what I said you are misreading and confusing volume w/ area.

caliper swept volume is the piston area x piston excursion which is the volume of fluid the m/c needs to provide, a bigger m/c pushes more fluid,

caliper swept area is the the annular area swept by the pad, this has nothing to do w/ the m/c

[winders]

Originally Posted by Bill Verburg

that is what I said you are misreading and confusing volume w/ area.

caliper swept volume is the piston area x piston excursion which is the volume of fluid the m/c needs to provide, a bigger m/c pushes more fluid,

caliper swept area is the the annular area swept by the pad, this has nothing to do w/ the m/c

I am not confusing the two. I just misread what you wrote. For some reason I read "area" instead of "volume". My mistake.....

Scott

[JeremyD]

Also depends on what you use the car for. Mine sees the track - and I am planning on a bigger motor in the future... So - and yes even with 3" caliper spacing - also a 74 - I switched to 993 front calipers - the machined down caliper and hat from Steve Weiner - rennsport systems (the wilwood rotors work too) - 965 rear calipers over a 930 rear rotor. I also installed a 23.3 Mercedes Benz non boosted truck MC (but be advised that you need a longer brake plunger pin)

Listen to Bill Verburg - he can definitely steer you in the right direction.

[T77911S]

if your brakes can lock up the wheels, and they dont fade out due to heat, (vented rotors with plenty of air), is there really any brake improvements that will shorten your stopping distance until you put on a tire that has more grip?

when i was looking at brakes for the BWM, which dont even come close the 911, someone said if the brakes can lock up, i am wasting money with bigger calipers/pads.

[RWebb]

that person gave you xlnt. info - big bad boy bling brakes are heavy and inhibit suspension action

you DO want to ensure that they will not fade under all conditions you will encounter in the future, given new fluid and any air ducting, yada yada...

[Eric_Shea]

What Randy said...

I restore a lot of brakes and the word "upgrade" is visiously tossed around by the online "Bigger is Better" crowd. A full 95% of the people who "have to have" an "upgrade" do not need it. When pressed they "might do an occasional auto-x now and again".

BMW calipers? Most are basically the ATE A-Caliper casting with a 3" spacing. Those are the absolute heaviest caliper Porsche ever put on a 911 at 9lbs 4oz each! Go with the Carrera version... add a 24mm (not needed) rotor to your early 911... say hello to nearly 20lbs of unsprung weight on a car that would be damn near impossible to get "fade" out of in stock trim.

Those Brembo's come in at 4lbs 8oz.

Want a break on brakes? Get yourself a full set of Porterfield R4S pads... bed them in properly and enjoy your new found stopping power. There's your upgrade.

[paulgtr]

ok, I am interested in trying these porterfield pads. any recommendations for where to get them?

[UrQuattro]

This might be a stupid question, but how are the porterfields when it comes to dust.
My wheels are the bbs basket weave style, and I can't take it anymore with the stock compound.

What would be a great pad that has minimal dust? Primarily street, occasional track.

Thanks. Hope this doesn't count as a hijack.

Micjael

[Flieger]

Originally Posted by paulgtr

ok, I am interested in trying these porterfield pads. any recommendations for where to get them?

I got mine from Eric. They do not seem to make any more dust than the normal Textars/ATE combo I had.

I think it is silly to ask brake pads to stop and not make any dust. It is like running while holding your breath.