911SC frotn brake upgrade recommendations

[francesconyc]

While replacing my brake pads, I noticed one of the pistons was hard to squeeze and may be seized. I was able to make it work but made me think that maybe I can use this opportunity to replace the calipers (love to add an accent color with some red brakes)

which brands or models are recommended? I also have brand new Zimmerman discs and new Ate fluid so maybe while I'm there I give my brake fresh start.

[Bill Verburg]

There are numerous ways to change the appearance of the brakes but to improve then not so many

The primary deficiency of 911 brakes is the limited scope of the thermal envelope, not brake torque

to address this you need some combination of the followingg
reduce weight
use the brakes less
bigger front rotor

better fresh fluid
pads w/ a higher operating range

if you also change to front calipers w/ bigger pistons you will also need t address the rear and m/c

The only change that avoids the later is to use 3.2 Carrera front calipers and rotors, these are a bolt on. and you don't need to do anything else If you want red paint them.

Beyond that it gets very expensive very fast and there are numerous pitfalls that will need to be avoided.

The best bolt on solution is the Elephant Racing 930 set up , the price is eye watering

[PeteKz]

Francesco: I'm in a similar situation, considering upgrading the brakes on my 1973T to handle the additional energy my 3.2 engine provides over the OE 2.4. I'll probably settle for 3.2 Carrera brakes too, both because my car is light, and it's not a race car.

Are you racing your car? I recall from other threads that you use it as a street car. If you are not racing it, just rebuild and repaint the calipers you have. Simple, cheap, and fast. As Bill has advised, getting really better brakes gets expensive quickly. It also takes a LOT more time to order, get everything installed, set up, and adjusted.

One other option to consider: Wilwood now offers a brake setup that has more braking capacity than the 3.2 setup, is less expensive than Elephant's 930 setup, and looks really cool. If you're "looking" for eye-candy, this would be your top choice.

https://www.wilwood.com/Porsche/Index

[Bill Verburg]

As I said many pitfalls

The Willwood 4/4 kits move bias to the front, not in a good way. It's not awful but it does waste thermal resources.

you can keep the stock m/c but would be far better off w/ a 930 m/c

As is usual for Wilwood there is no mention of dust seals, very desirable to have these.

[ahh911]

franc,

I received good advice on this board several years back. My front left caliper was sticking, advice was to work them in and out a few times (wood spacer when pushing on pedal).

Having just replaced the pads about two weeks ago where it's been two years perhaps and around 10k miles since I loosened that side, the caliper retracted very nicely and it stops straight as an arrow. Just saying, may be from lack of use or what have you.

Phil

[francesconyc]

Thanks guys. Yes im using it as street car.

It sounds like probably rebuilding them and maybe painting them is the easiest way to go…

[dannobee]

The Wilwood kit in the link has 1.38" pistons in front and 1.12" pistons in the rear, which would move the bias slightly more toward the rear than the stock SC brakes. Pedal effort would be slightly less than the stock SC brakes.

I looked at some Wilwood kits years ago, and it looks like they updated their offerings.

[Queefchief]

Every Porsche person is gunna tell you leave them stock and leave well enough alone.

I chose to run Wilwood and have loved them. No dust seals but that has also been a non issue if serviced and inspected like they should. Brakes are the most important piece on your car, that's why stock is the easiest choice.

If interested the Wilwoods I run upfront. Part# 120-11128

[Bill Verburg]

Originally Posted by dannobee

The Wilwood kit in the link has 1.38" pistons in front and 1.12" pistons in the rear, which would move the bias slightly more toward the rear than the stock SC brakes. Pedal effort would be slightly less than the stock SC brakes.

I looked at some Wilwood kits years ago, and it looks like they updated their offerings.

correct premise wrong conclusion, the hyd. ratio does stay close to stock and is a little more rear but the bigger diameter of the front rotors moves brake torque forward from 1.491(nearly perfect most of the time) to 1.754

[Jonny042]

Originally Posted by Queefchief

Every Porsche person is gunna tell you leave them stock and leave well enough alone.

I chose to run Wilwood and have loved them. No dust seals but that has also been a non issue if serviced and inspected like they should. Brakes are the most important piece on your car, that's why stock is the easiest choice.

If interested the Wilwoods I run upfront. Part# 120-11128

Are those bolt-on? I see the center to center distance for the mounting ears is 3.5"...

[Bill Verburg]

Originally Posted by Queefchief

Every Porsche person is gunna tell you leave them stock and leave well enough alone.

....... No dust seals but that has also been a non issue if serviced and inspected like they should. .....
If interested the Wilwoods I run upfront. Part# 120-11128

There's the issue, 99.99% of all street users will rarely if ever inspect their brakes

dust seals are there for a reason on every street car and most track cars

[Locker537]

Send your original calipers to PMB for restoration. Top quality work at a very reasonable price.

Or, rebuild them yourself because you want to. It's not a hard job. Painting will take the most time.

If you want an upgrade, replace all 4 calipers with those from a 3.2 Carrera as Bill suggests. That is what I have on a 99% track car with cooling ducts on the front.

[dannobee]

I was talking about their kits with the stock diameter front and rear rotors. Braking would be nearly identical to the stock setup.

I have no idea why they don't offer bigger diameter rear rotors to match their 12.19" front rotor. There should be a ~12.5" diameter rear to match the 12.19" fronts.

The thermal mass of the wilwood kits is still inferior to the 930 brakes, albeit at a much lower cost. Again, no idea why they went with relatively thin rotors when they could have stepped up to 930 sized rotors, unless it's all about "the look" with stock type performance.

[jac1976]

Originally Posted by Locker537

Send your original calipers to PMB for restoration. Top quality work at a very reasonable price.

Or, rebuild them yourself because you want to. It's not a hard job. Painting will take the most time.

If you want an upgrade, replace all 4 calipers with those from a 3.2 Carrera as Bill suggests. That is what I have on a 99% track car with cooling ducts on the front.

Not sure this is exactly what Bill recommends without a few other changes.

[shoooo32]

Running Porterfield R4S pads, my full weight SC targa with a 3.2ss could build enough heat to get the pedal mushy in the canyons (especially at altitude). Switching out to Carrera calipers with wider rotors seemed to help. The pedal stayed noticeably firmer. This is an extreme use case for a street car - I don't see why anyone would need more (beyond just wanting the appearance of big brakes).

[Bill Verburg]

Originally Posted by jac1976

Not sure this is exactly what Bill recommends without a few other changes.

If you go w/ the 3.2 Carrera calipers only use the fronts. The rears have pistons that are too large(though some A/Xers may like them to rotate the car better at slower speeds) and you don't need to increase the rear thermal envelope.

[Bill Verburg]

Originally Posted by shoooo32

Running Porterfield R4S pads, my full weight SC targa with a 3.2ss could build enough heat to get the pedal mushy in the canyons (especially at altitude). Switching out to Carrera calipers with wider rotors seemed to help. The pedal stayed noticeably firmer. This is an extreme use case for a street car - I don't see why anyone would need more (beyond just wanting the appearance of big brakes).

add 993 or GT3 cooling scoops to the A-arms and use Castrol SRF

[Bill Verburg]

Originally Posted by dannobee

I was talking about their kits with the stock diameter front and rear rotors. Braking would be nearly identical to the stock setup.

I have no idea why they don't offer bigger diameter rear rotors to match their 12.19" front rotor. There should be a ~12.5" diameter rear to match the 12.19" fronts.

The thermal mass of the wilwood kits is still inferior to the 930 brakes, albeit at a much lower cost. Again, no idea why they went with relatively thin rotors when they could have stepped up to 930 sized rotors, unless it's all about "the look" with stock type performance.

If you use the stock rotors than you haven't addressed the real issue, In fact you have made it worse because the total piston area of the Willwoods is now bigger it more desirable to change the m/c to a 930 version. You don't have to but the pedal is going to be softer and have longer travel, both are bad things. Additionally the larger piston area makes it possible to put more heat into the already stressed rotors. nd the equal sized pistons will cause pad tapered pad wear, 930s overcome this w/ stepped pistons which Willwood doesn't use. All other brake manufacturers went to staggered pistons to address that issue decades ago.

as i said pitfalls galore

[mike sampsel]

Originally Posted by Bill Verburg

There's the issue, 99.99% of all street users will rarely if ever inspect their brakes

dust seals are there for a reason on every street car and most track cars

https://www.wilwood.com/calipers/CaliperList?subname=FNSL4R-Dust%20Seal

Looks like these wilwoods have dust wiper/seals.

Looks to be the same calipers in the kits too, but they are not stated as DS type. Need to ask wilwood if you are interested. The kit caliper and the DS caliper in the link above have the exact dimensions. So .. ask wilwood about the dust seals and the kits for 911.
You can get lots of colors too.

https://www.wilwood.com/Calipers/ColoredCalipers

[Queefchief]

Originally Posted by Jonny042

Are those bolt-on? I see the center to center distance for the mounting ears is 3.5"...

Very minor modification to mount. But yes pretty much bolt on my SC