Best brake upgrade for 15" wheels?

GT2BH · 03-12-2015, 09:52 AM

I just received my 15x7 and 15x8 fifteen52 outlaws for my 1983 911sc project. I want to upgrade the current brakes, and I was wondering what would be the best setup for a street/track car that will fit under the 15" wheels..

KTL · 03-12-2015, 10:04 AM

930 brakes front & rear are the most popular and fairly easy. A bit expensive but very very good in terms of fit and performance.

A "poor man's" version of that would be to use 930 front calipers, Wilwood 11.75"x1.25" GT rotors & flat 1/4" hats. On the rear use Carrera 3.2 calipers and Carrera 3.2 rotors. This 930 want-to-be setup performs very well and retains the original master cylinder. We've used a similar setup with 964/944T calipers adapted by VCI, the required '86 944T front rotors (spindle spacers needed too) and the Carrera 3.2 rear brakes. 911 Brake Upgrades using 964/944T calipers Also performs very good and retains original master cylinder

H-viken · 11:46 AM

Has anyone tried the Wilwood or A.P Racing calipers?

Would they fit?

KTL · 03-12-2015, 11:59 AM

Wilwoods (forged superlite, I believe) are offered in 3.5" mount spacing and bolt right up. I've seen people use them on stock rotors.

The AP racing calipers also fit on the 3.5" mount spacing. I've seen them on Jerry Woods Enterprises Spec 911 cars.

H-viken · 12:36 PM

These maybe? Wilwood Billet Narrow Dynalite Brake Caliper Side Inlet Lug Mount | Demon Tweeks

KTL · 03-12-2015, 02:24 PM

Do a search for "wilwood" and username jpahemi. He use the forged superlites them on SC rotors (20mm = 0.81") which really doesn't address more heat sink capability that is gained when using a larger rotor. Not to mention the straight-vaned SC and Carrera rotors aren't very good at "pumping" air thru their vanes.

Interesting new Porsche/Wilwood brake option

Here's the AP calipers used on the SP911 car I previously mentioned. They're also on stock size rotors (Carrera 24mm in this case) so I suspect the gain there is reduced unsprung weight with the aluminum alloy calipers?

The fronts look like radial mount, so they had to make adapter blocks to fit them to the struts. I rears are probably lug mount too

Fronts? https://www.apracing.com/product_details/road_car_upgrades/road-aftermarket_brake_calipers/4_piston_calipers/cp6600_family-130mm_mounting_centres-suits_%C3%B8330mm_disc.aspx

Rears? https://www.apracing.com/product_details/road_car_upgrades/road-aftermarket_brake_calipers/4_piston_calipers/cp7600_family-130mm_mounting_centres-suits_%C3%B8295x24mm_disc.aspx

78-911SC · 03-12-2015, 04:31 PM

Kevin I've read that you can get the turbos under 15" wheels but not sure what widths. Have you ever heard of anyone getting them under 15" steelies?

GT2BH · 03-13-2015, 12:53 AM

KTL, do you suggest I hunt for the 930 calipers or go for the AP calipers on stock rotors? Will these AP fit under the 15" wheels with no modification?

3literpwr · 04:07 AM

I have these in my basement for my build. The H calipers are used in many rally applications and gravel tires only come in 15"

Alcon brakes & clutches

KTL · 03-13-2015, 09:44 AM

I do know for certain the 930 calipers fit inside the 15" Fuchs. There are pictures here on the site and they've typically been shared by Bill Verburg.

I haven't heard of them going under steel wheels. If you have a picture of the back side of a steelie, we could look at it's profile compared to the typical inner barrel of the Fuchs.

Regarding the 930 calipers, they are a bit expensive but worth it IMO. They fit perfectly over the larger rotor and you'll have a "native" caliper and a robust rotor to handle the heat. The deficiency in the stock rotors is their thermal mass is in need of more mass to better handle the heat

The AP calipers are nice (AP is among the best in brakes) but you'd have to get caliper adapters made and also the brake pad selection is a bit more challenging to find the pads you like to use. Whereas the 930 size pad is very common and you can get pretty much any make of brake pad compound for them.

Those Alcon calipers are nice. I've got a connection with Alcon in case you need anything in the future. I work for cstreit on his alconkits.com site and we deal with Alcon USA directly when "loose" parts are needed. Let me know if you need pads. We can get the Hawk HB107 pad in whatever compound you prefer within a week's time and we can also source the Pagid U1265 pad shape from our USA supply chain. Sometimes we have to go direct to Alcon UK for misc. Alcon stuff and that takes at least 4 weeks since they're on their own timeline and seems like we get our stuff shipped out to us via the slow boat around Greenland!

GT2BH · 03-13-2015, 10:09 AM

Thanks for the input Kevin.

So, lets say I go with the 930 calipers. I'm assuming these are the 930 turbo calipers? what would your full shopping list be for brakes? what about the cooling kits that our host sells?

jpnovak · 03-13-2015, 10:34 AM

What is it about your stock brakes that is the reason for the upgrade?

Do you track the car?
Do you overheat the brakes (unlikely on the street)?
Do you have stock brakes in perfect working order?
Do you want cosmetics?

The stock SC brakes are great. My order of upgrades would be the following...

1. Driver Technique.
2. Cooling Ducts
3. Really good brake pads
4. Carrera 3.2 brakes on front for 24mm rotor width
5. Brake upgrade. (Yes, this is last on the list).

The 930 brakes will need 4X calipers, Early (78-79) front rotor hats, Early front rotors (non-offset), rear 930 rotors, 23mm Master Cylinder, modified actuator pin (not sure on vacuum boost cars), new hard lines at strut and trailing arms.

Front installation is bolt-on. Rear requires trimming brake dust cover mount trimming.

The 930 is a great braking system on a standard 911. Just make sure you need it.

LJ851 · 03-13-2015, 11:10 AM

Quote:

Originally Posted by jpnovak

3. Really good brake pads

What are the current top choices for a "really good brake pad"

Mostly street use .

Driven97 · 03-13-2015, 11:11 AM

I just want to see a photo of the OP's wheels.

KTL · 03-13-2015, 12:28 PM

Agreed on Jamie's analysis of approaching improving the brakes. Technique is a big problem for a lot of people. Driving on the street creates bad habits that translate to the track and it takes awhile to learn to unlearn the street braking.

Cooling is something the brakes do indeed lack. The Fuchs are great wheels but do not do much to help cooling. Removal of the splash shields helps get the rotors better exposed to the air. Ducts are a great approach but the routing of the hoses is often not very straight and that kills the velocity of the air. Ducts also like to have suitable backing plates with a hose spigot in the plate to direct the cooling air into the rotor eye.

A suitable alternative to ducting is scoops like the 993 has in the front. They work quite well and are cheap & easy to install with a drill and some zip ties. Do a search- i've participated in a few of the scoop discussions.

Stock brakes are quite capable but their shortcoming is the seals and the iron caliper body is a good heat sink (and not as good at releasing the heat). The Ate or FTE brand seals for these calipers are not very heat tolerant. Hence the point that getting the brakes cooled is important since you're attacking the problem at the source along with using the necessary retardants (higher temperature fluid, race pads) to combat the heat.

Carrera brakes are good but they're still wanting a bit more in really hard use. They still require periodic caliper rebuilds (pressure seals eventually leak -dangerous- and the dust boots turn to dust- both indicative of considerably high brake temps) and rather frequent pad & rotor replacement.

I'm not saying upsized expensive brakes are an absolute must. The stock brakes can be managed well, perform well and are very durable for years and years. But the upsize in brakes does come with notably improved performance. Pads and rotors last much much longer, caliper seals don't fail, brake fluid bleeding before each track event is no longer an absolute must (but certainly a good practice especially if you ever feel the pedal getting soft)

The list for the 930 setup that Jamie provided is spot-on. But it can be enhanced a little bit IMO.

Quote:

The 930 brakes will need 4X calipers, Early (78-79) front rotor hats, Early front rotors (non-offset), rear 930 rotors, 23mm Master Cylinder, modified actuator pin (not sure on vacuum boost cars), new hard lines at strut and trailing arms.

Front installation is bolt-on. Rear requires trimming brake dust cover mount trimming.

930 front calipers are great and bolt right on the SC strut with the factory 3.5mm spacing washers. You do need to install a longer hard brake line and the original 930 line is direct fit. Or you can bend your own.

The rotor does not have to be the 78-79 floating style. A few examples of alternative rotors are the really nice Wilwood GT (i'm disappointed Wilwood appears to be discontinuing the HD line) or the fantastic AP racing 60 vane rotor. The AP disc is kickass disc and a great value at $165 each. I'll be giving those a try at my next rotor replacement.

Wilwood High-Performance Disc Brakes - Rotor No: 160-11837

Essex - AP Racing J Hook

Both the above rotors use a common 8 x 7.00" hat circle and that allows use of Rebel's very nice 8 bolt mounting hats. (1/2 way down the page)

brake system components Rebel S Racing Products

This bolted/fixed rotor & hat combo is a much cheaper and very good alternative to the factory floating $etup. But if you really feel like you want floaters for best performance in heavy duty environment, floating is indeed the better the way to go. OEM Zimmerman, Sebro rotors are excellent and Brembo also makes a copy of this rotor. However, $350 per rotor is NOT cheap

1979 Porsche 930 Turbo Coupe - Brake Pads & Rotors - Page 2

To make the OEM floating rotors work, you can use the Rebel 12 bolt hats in the above link and use Coleman Racing T-locks with the hardware of your choice. Beware, these truly floating rotors are freakin' noisy once they loosen up & are cold

T-Lock, Floating Rotor Mount

Jamie is indeed correct that the 930 calipers require the 23.8mm 930 master cylinder. On vacuum boosted cars, the '78-'89 930 master cylinder is a direct bolt in no modifications necessary installation.

The rear 930 calipers are not a must. You can cut costs there by using a more common small Brembo rear caliper from the 964, 993, 928, 944T, etc. The 28/30 piston sizing of the 964/944T/968/928 is a cheap alternative to the 30/30 sized 930 caliper in terms of cost to buy and adapting to the 911 rear axle. Use of these calipers with the 930 fronts gives you 964-like hydraulic bias which is pretty decent. However these calipers need to be widened inside to allow the 930 rotor to fit.

It's not that hard 993 Caliper Mods- Grinding and Drilling

Actually the 993 or 964T rear caliper with its larger 30/34 pistons is a great choice for the hydraulic bias it creates. Its a bit aggressive in the neighborhood of 993RS type bias. So a well set up car with limited slip diff would be important to tame the more aggressive rear brake bias. 964T caliper is the best choice because it's already the proper internal width for the 930 309x28mm rotor and doesn't require widening. Routing the fluid feed line to these common Brembos is also easier than the 930 caliper. Simply re-bend the existing line from your SC caliper.

So as you can see, you can go pure 930 front and rear but it's pretty expensive. Like Jamie said, do you really need this. Or you can change things up a bit and mix & match things to create a Frankenstein 930-like combo. Frankenstein 930 brake setup is not bargain basement cheaper but it is a considerable savings over pure 930. The cost savings in calipers alone is $800 on average (used 930 rears are typically $1000 whereas you can get common Brembo rears all day long off eBay for ~$200 or ~$400 for the 993 or 964T) and you also save a bit more in the simpler adapting of the common Brembos. You can DIY the adapting of the common Brembos if you have a drill press and some patience. Or give it to a machinist and they'll knock it out for a decent price. The 930 adapting should be undertaken by a machinist for sure.

billewizz · 03-13-2015, 12:33 PM

If all porsche items are your choice boxster calipers 930 turbo discs and adaptor brackets from fvd in Germany, i know of a race car here in the uk that has this set up and it has proved to be very effective with porterfield pads running under 15" wheels.

GT2BH · 03-14-2015, 03:07 AM

So much useful info, its going to take me a while to digest. The purpose of the question is that I am rebuilding my car to a very high spec so I wanted the best investment for the future. Maybe I'll stick to rebuilding the stock calipers and going for good pads and rotors for the time being. I think cooling is important and that I might as well do something while I have the suspension out (converting to coilovers).

Pics of wheels as requested

3literpwr · 03-14-2015, 03:35 AM

Thanks for the offer on future assistance KTL. I may need it at some point. From a pad perspective, I have really liked Carbotech (xp10) in previous applications. I had actually got the Alcon units when I was running my old open class Galant VR4 but had good results with the factory Mitsu stuff for some time.

Also, those wheels look killer!

Quote:

I do know for certain the 930 calipers fit inside the 15" Fuchs. There are pictures here on the site and they've typically been shared by Bill Verburg.

I haven't heard of them going under steel wheels. If you have a picture of the back side of a steelie, we could look at it's profile compared to the typical inner barrel of the Fuchs.

Regarding the 930 calipers, they are a bit expensive but worth it IMO. They fit perfectly over the larger rotor and you'll have a "native" caliper and a robust rotor to handle the heat. The deficiency in the stock rotors is their thermal mass is in need of more mass to better handle the heat

The AP calipers are nice (AP is among the best in brakes) but you'd have to get caliper adapters made and also the brake pad selection is a bit more challenging to find the pads you like to use. Whereas the 930 size pad is very common and you can get pretty much any make of brake pad compound for them.

Those Alcon calipers are nice. I've got a connection with Alcon in case you need anything in the future. I work for cstreit on his alconkits.com site and we deal with Alcon USA directly when "loose" parts are needed. Let me know if you need pads. We can get the Hawk HB107 pad in whatever compound you prefer within a week's time and we can also source the Pagid U1265 pad shape from our USA supply chain. Sometimes we have to go direct to Alcon UK for misc. Alcon stuff and that takes at least 4 weeks since they're on their own timeline and seems like we get our stuff shipped out to us via the slow boat around Greenland!

3literpwr · 03-14-2015, 03:36 AM

Thanks for the offer on future assistance KTL. I may need it at some point. From a pad perspective, I have really liked Carbotech (xp10) in previous applications. I had actually got the Alcon units when I was running my old open class Galant VR4, but had good results with the factory Mitsu stuff for some time and never installed them.

Also, those wheels look killer!

Quote:

I do know for certain the 930 calipers fit inside the 15" Fuchs. There are pictures here on the site and they've typically been shared by Bill Verburg.

I haven't heard of them going under steel wheels. If you have a picture of the back side of a steelie, we could look at it's profile compared to the typical inner barrel of the Fuchs.

Regarding the 930 calipers, they are a bit expensive but worth it IMO. They fit perfectly over the larger rotor and you'll have a "native" caliper and a robust rotor to handle the heat. The deficiency in the stock rotors is their thermal mass is in need of more mass to better handle the heat

The AP calipers are nice (AP is among the best in brakes) but you'd have to get caliper adapters made and also the brake pad selection is a bit more challenging to find the pads you like to use. Whereas the 930 size pad is very common and you can get pretty much any make of brake pad compound for them.

Those Alcon calipers are nice. I've got a connection with Alcon in case you need anything in the future. I work for cstreit on his alconkits.com site and we deal with Alcon USA directly when "loose" parts are needed. Let me know if you need pads. We can get the Hawk HB107 pad in whatever compound you prefer within a week's time and we can also source the Pagid U1265 pad shape from our USA supply chain. Sometimes we have to go direct to Alcon UK for misc. Alcon stuff and that takes at least 4 weeks since they're on their own timeline and seems like we get our stuff shipped out to us via the slow boat around Greenland!

blucille · 03-14-2015, 04:57 AM

I've bren very happy with porterfields that I've run on various cars