Rear brake Upgrade

[yellow03vert]

I already have the Stoptech big brake kit on the front, but now I want to upgrade my rear brakes. I am mostly doing it for the look because the rear looks tiny compared to the front and the brakes already work great. I seen that Bear made a 13" kit for the Gt's but I can not find any for the Cobra without spending 3k+. Does anyone know of any rear upgrade kits? Thanks

 

[mu22stang]

This thread has some good information on a rear brake upgrade kit, starting at post #25...http://www.svtperformance.com/forums/suspension-258/627369-two-piece-13-cobra-front-rotors-soon-available-two-versions.html#post8710738

 

[yellow03vert]

Thanks for the link I have searched a lot and it never came up. Anybody else know of any kits for the rear?

 

[cobraracer46]

Here is a brembo GT 13'' rear brake set up on a 2003 Mach 1 mustang. The parking brake is the same as the Ford GT. A shop in Washington state wants $3000 for this kit. Brembo does not offer this kit for a Mustang, but after doing some research, I've come to the conclusion that the un named shop in washington simply got a rear brembo kit originally designed for an import vehicle and adapted to work on a mustang. I know that there are some import vehicles with the same lug nut spacing as a Ford, so one day I will just get all of the fancy Brembo parts used and fab up a bracket for the Calipers. another thing to look out for is the caliper piston sizes as they must by smaller than the front caliper piston sizes.

 

[mu22stang]

Here is a brembo GT 13'' rear brake set up on a 2003 Mach 1 mustang. The parking brake is the same as the Ford GT. A shop in Washington state wants $3000 for this kit. Brembo does not offer this kit for a Mustang, but after doing some research, I've come to the conclusion that the un named shop in washington simply got a rear brembo kit originally designed for an import vehicle and adapted to work on a mustang. I know that there are some import vehicles with the same lug nut spacing as a Ford, so one day I will just get all of the fancy Brembo parts used and fab up a bracket for the Calipers. another thing to look out for is the caliper piston sizes as they must by smaller than the front caliper piston sizes.

Wow! You would never be able to balance the brakes when you put those Brembos on the rear of an SN95, which look to be the 4-piston '00 R calipers. You'd have to put oil on the pads to dial off enough bias.

 

[sprstr1000]

brakes

Wow! You would never be able to balance the brakes when you put those Brembos on the rear of an SN95, which look to be the 4-piston '00 R calipers. You'd have to put oil on the pads to dial off enough bias.

Hey I have never heard the term balance the brakes???
Are you talkin like balancing a wheel?????

 

[sprstr1000]

bear

I already have the Stoptech big brake kit on the front, but now I want to upgrade my rear brakes. I am mostly doing it for the look because the rear looks tiny compared to the front and the brakes already work great. I seen that Bear made a 13" kit for the Gt's but I can not find any for the Cobra without spending 3k+. Does anyone know of any rear upgrade kits? Thanks

Im running the bear 14inch rotor with the 6S calipers in the front and am havin a hell of a time finding a kit for the rear and being able to retain my parking brake

the conclusion I have come to is Im just gonna order a 13ich two peice rotor for the front and install it on the rear and order a bear 4 piston caliper an have a bracket fabbed up for it

I was lookin at the ebrake kit from the pic above but it is over priced so im gonna run a hydraulic ebrake

 

[cobraracer46]

Wow! You would never be able to balance the brakes when you put those Brembos on the rear of an SN95, which look to be the 4-piston '00 R calipers. You'd have to put oil on the pads to dial off enough bias.

You are incorrect.

The rear brembo kit I posted up uses a Brembo GT2 caliper that is designed to work with the Brembo F50 front caliper like the one I have on my 2001 Mustang Cobra. No bias adjustments are needed.

Brembo piston sizes here:
Second Digit: Caliper Type Piston Sizes
0 = No Caliper in Kit
1 = Lotus-Type 4-Piston 36 - 40
2 = F40-Type 4-Piston 38 - 44
3 = F50-Type 4-Piston 40 - 44
9 = Porsche 4-Piston 36 - 44
A = GT2 4-Piston (Lotus-Type) 36 - 40

 

[mu22stang]

Hey I have never heard the term balance the brakes???
Are you talkin like balancing a wheel?????

Think of the balance in terms of force. For example: 70% of the braking force comes from the front, 30% from the rear. This balance determines the efficiency of the braking system and changes in the vehicle's stability under various braking conditions.

You are incorrect.

The rear brembo kit I posted up uses a Brembo GT2 caliper that is designed to work with the Brembo F50 front caliper like the one I have on my 2001 Mustang Cobra. No bias adjustments are needed.

Brembo piston sizes here:
Second Digit: Caliper Type Piston Sizes
0 = No Caliper in Kit
1 = Lotus-Type 4-Piston 36 - 40
2 = F40-Type 4-Piston 38 - 44
3 = F50-Type 4-Piston 40 - 44
9 = Porsche 4-Piston 36 - 44
A = GT2 4-Piston (Lotus-Type) 36 - 40

A brake balance in the hydraulic system would definitely need to take place, especially if you are saying the same calipers would go on the front and rear. In fact, an entire system redo would probably need to take place. I'm not sure how well the front rotors clamp, but the rear tires would likely flatspot (or ABS flutter) long before the fronts could ever even get to their maximum performance. There is a reason Mustang rear brakes are so puny.

This seems like a nice piece of eye candy, but I don't think it would provide justifiable performance. Doesn't seem like anybody that tracks SN95's uses this kit. Overpriced? Lacks performance? I don't know...

 

[cobraracer46]

Think of the balance in terms of force. For example: 70% of the braking force comes from the front, 30% from the rear. This balance determines the efficiency of the braking system and changes in the vehicle's stability under various braking conditions.



A brake balance in the hydraulic system would definitely need to take place, especially if you are saying the same calipers would go on the front and rear. In fact, an entire system redo would probably need to take place. I'm not sure how well the front rotors clamp, but the rear tires would likely flatspot (or ABS flutter) long before the fronts could ever even get to their maximum performance. There is a reason Mustang rear brakes are so puny.

This seems like a nice piece of eye candy, but I don't think it would provide justifiable performance. Doesn't seem like anybody that tracks SN95's uses this kit. Overpriced? Lacks performance? I don't know...

First off, the F50 brembo caliper has larger pistons than the Brembo GT2.

Second, Brembo has enginnered the GT2 caliper to work with the F50 front caliper. No hydralic brake balancing is needed as the GT2 caliper pistions are sized smaller than the front F50 caliper pistons.

Third, there is a perfomance benifit to running a larger rear brake on a mustang
Quoated from Maximum Motorsport:
MM Wilwood IRS Rear Racing Brake Conversion Kit, floating rotor

[click for larger image]
$1,597.00
Part #: MMBAK-16
Manufacturer: Wilwood

Note:
Actual product may differ from photo.
Add:


MM IRS Racing Brake Kit, 1999-2004 Cobra IRS, Full-floating rotor hat

Click here for a much larger product image.

IRS Racing Brake Kits

MM developed these IRS brake kits on our own American Iron racecar because we found the temperature of our standard Cobra rear rotors exceeded 1,200 degrees at the end of a track session. Once we installed this kit our rotor temperatures were reduced to less than 900 degrees, and the rigid four-piston caliper greatly improved brake pad life and pedal feel by eliminating taper wear of the pads.

The lower center of gravity, longer wheelbase, better weight balance, and improved suspension of a racecar reduces forward weight transfer during braking, which gives the car the ability to utilize more rear brake bias than a street-oriented Mustang suspension can tolerate. Dialing in more rear brake with an adjustable proportioning valve will overwhelm the thermal capacity of the stock Cobra rear brakes. The larger rotors of the MM kit provide more thermal mass, allowing an increase in rear brake bias while keeping temperatures lower than with the stock Cobra rotors.

The increase in thermal capacity provided by this MM kit allows increasing the rear brake bias. This allows a more proper match of the rear brake capacity to upgraded front brakes. A better balanced, better performing brake system not only shortens stopping distances, it inspires driver confidence, which leads to lower lap times.

Two versions of the kit are available. Both kits utilize a two-piece hat and rotor assembly. The MMBAK-15 kit includes fixed hat rotors, while the MMBAK-16 kit has floating hats. Our exclusive mounting brackets easily attach the Wilwood calipers to the standard Cobra IRS spindle.

The MM IRS Racing Brake Kit should only be installed with properly matching front brakes. The appropriate minimum size front rotor is the standard Cobra 13" rotor. The thicker rotors of a StopTech front brake kit are much more desirable. The stock Cobra aluminum PBR sliding-bridge calipers are the minimum suitable front caliper choice. Fixed-mount four-piston front calipers provide a much more balanced match with the Wilwood calipers of this MM kit.

The MM IRS Racing Brake Kits include
Two-piece, directional, 12.72" x 1.25" vented and slotted rotors for increased brake cooling and stopping power. Rotors are larger diameter and thicker than stock rotors, increasing thermal capacity. They have larger cooling vanes and asymmetric slots to improve cooling.
Rotor hats are machined from aluminum for reduced weight. Hats are available in either fixed or floating versions.
Four-piston forged aluminum Wilwood calipers are lightweight; yet provide high brake torque for maximum stopping performance. Calipers utilize larger-than-stock pads. The increase in friction material volume prolongs pad life.
Stainless steel brake hoses are included, replacing the stock rubber hoses for improved pedal feel and increased reliability under the extreme stress of open track use.
Important Notes
This kit does not include a parking brake. Installation of this kit will disable the stock parking brake, making it non-functional.
The four-piston calipers require more clearance to the wheel spokes than the stock Cobra Varga rear caliper. Wheels that clear 4-piston front calipers from Brembo and StopTech will clear these Wilwood calipers.
Brake pads are not included with this kit because they should be chosen to complement the front pad compound on your racecar. Contact a MM Tech Associate to discuss your performance brake pad needs.
MM carries high performance brake fluid, found here.

 

[mu22stang]

First off, the F50 brembo caliper has larger pistons than the Brembo GT2.

Second, Brembo has enginnered the GT2 caliper to work with the F50 front caliper. No hydralic brake balancing is needed as the GT2 caliper pistions are sized smaller than the front F50 caliper pistons.

...The lower center of gravity, longer wheelbase, better weight balance, and improved suspension of a racecar reduces forward weight transfer during braking, which gives the car the ability to utilize more rear brake bias than a street-oriented Mustang suspension can tolerate. Dialing in more rear brake with an adjustable proportioning valve will overwhelm the thermal capacity of the stock Cobra rear brakes. The larger rotors of the MM kit provide more thermal mass, allowing an increase in rear brake bias while keeping temperatures lower than with the stock Cobra rotors....

I'd like to see some literature on the engineering Brembo did on the F50 front/GT2 rear on a SN95 Mustang...

As far as the article from MM. See the highlighted red. You don't add more clamping force unless you intend on 1) adding rotor mass to dissipate the increase heat load and 2) reevaluating the brake bias through modifications to the master cylinder. There is no way around it.

Furthermore, the OP stated this was for aesthetics. The MM article is for a racecar. If you want bigger rotors to look cool on the street, bigger rotors and a caliper relocation bracket is the way to go.

 

[cobraracer46]

I'd like to see some literature on the engineering Brembo did on the F50 front/GT2 rear on a SN95 Mustang...

Look here: http://www.racetechnologies.com/images/medialibrary/Brembo_Racing_Catalog_2009.pdf

reevaluating the brake bias through modifications to the master cylinder. There is no way around it.

Incorrect. The bias in the Brembo system as well as the MM kit is accomplished with larger front caliper piston sizes and smaller rear caliper piston sizes. No modifications to the master cylinder are needed. Another thing, On a SN95 mustang, there is no real place to put a brake bias valve as there are two hard lines going to the rear unlike the old Fox body cars that have a singe line going through the engine compartment and then out to the rear.

 

[mu22stang]

I retract my statement as I interpreted that paragraph incorrectly. The theory that increasing the rear rotors mass will allow you to dial in more brake bias with a stronger rear caliper clamping force is indeed there.

I still don't know who in their right mind would do this. I mean, last time I checked, Bruce was using 13" rotors with the stock single piston caliper to compliment his 14" fronts. There's no way this is "necessary" on anything less than an AI car or the sort.

 

[sprstr1000]

Think of the balance in terms of force. For example: 70% of the braking force comes from the front, 30% from the rear. This balance determines the efficiency of the braking system and changes in the vehicle's stability under various braking conditions.



A brake balance in the hydraulic system would definitely need to take place, especially if you are saying the same calipers would go on the front and rear. In fact, an entire system redo would probably need to take place. I'm not sure how well the front rotors clamp, but the rear tires would likely flatspot (or ABS flutter) long before the fronts could ever even get to their maximum performance. There is a reason Mustang rear brakes are so puny.

This seems like a nice piece of eye candy, but I don't think it would provide justifiable performance. Doesn't seem like anybody that tracks SN95's uses this kit. Overpriced? Lacks performance? I don't know...

Thanks I just have never heard the word balance to describe it
Ive only heard BIAS

 

[SlowSVT]

yellow03vert

If this more as an appearance upgrade then just get the system you like but you may loose the parking brake in the process.

If you feel you need to upgrade the rears to improve the ability for the car to stop and delay fade I wouldn't sweat the size of stock rear discs which are bigger then the fronts on some cars. If you are road racing it that would be a different story. For the street they are more then adequate and will provide less unsprung mass compared to big discs which will compliment the IRS.

On motorcycles the rear disc role in stopping the bike takes on less important the harder you stop as more of the weigh shifts forward. I run a tiny titanium disc on one of my bikes which is next to worthless for stopping but it only weighs 8 oz compared to the massive dual iron full floaters up front. I rarely use the rear brake on a bike anyhow other then trail braking.

The best mod for you IMO is a lightweight two piece stock replacement rotors and a set of steel lines and decent pads plus your get to keep the parking brake.

Once in a while I see cars with huge rotors out back which kinda has me scratching my head why are they adding all that brake mass where the fronts will be fading long before the rears. Compounded by the fact that the driver is more likely to get a second visit from the tooth fairy long before they overheat their discs. The stock Terminator brake system is designed to bring the down to a stop from 150 mph. Lets just say for simplicity the added mass of the big Stoptech binders will now haul your convertible down to stop from 170

 

[yellow03vert]

I am mostly wanting bigger rears for the look, but I do plan on taking the car to the auto-x this year once or twice. I really want to keep my parking brake because I park on a hill. Maybe I will just get the two piece bear rotors to keep the unsprung weight down. I was hoping to find a good 13" two piece kit that uses the stock calipers. Stage 3 motorsports sells a Alcon/Roush kit that uses the stock caliper but it uses a a one piece rotor and I can not find anybody that has used it to get feedback.

 

[MWR]

Look here: http://www.racetechnologies.com/images/medialibrary/Brembo_Racing_Catalog_2009.pdf

Incorrect. The bias in the Brembo system as well as the MM kit is accomplished with larger front caliper piston sizes and smaller rear caliper piston sizes. No modifications to the master cylinder are needed. Another thing, On a SN95 mustang, there is no real place to put a brake bias valve as there are two hard lines going to the rear unlike the old Fox body cars that have a singe line going through the engine compartment and then out to the rear.

:lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol::lol:

 

[LoudToy948]

Here is a brembo GT 13'' rear brake set up on a 2003 Mach 1 mustang. The parking brake is the same as the Ford GT. A shop in Washington state wants $3000 for this kit. Brembo does not offer this kit for a Mustang, but after doing some research, I've come to the conclusion that the un named shop in washington simply got a rear brembo kit originally designed for an import vehicle and adapted to work on a mustang. I know that there are some import vehicles with the same lug nut spacing as a Ford, so one day I will just get all of the fancy Brembo parts used and fab up a bracket for the Calipers. another thing to look out for is the caliper piston sizes as they must by smaller than the front caliper piston sizes.

This car actually belongs to a friend of mine. I know the shop and person that did the work. This car has close to 75K in mods with under 10k on the odometer. He actually tracks this car, and now has a new Shelby that he is doing some crazy work too.

Anyhow, this brake kit was actually designed for Panoz. It bolts right up to an IRS system, and requires some serious upgrades if its a stick axle. It is actually two brake kits. It is a 13" Brembo Grand Touring kit, and the small caliper is by Mclaren and is used for parking brake only. For a stick axle application, you would need a torsen diff, new axles, and a specific bracket that the unnamed shop had designed specifically for this Mach 1.

I have driven this car once, and I can tell you, when you hit the brakes hard, it stops like a roller coaster. It takes all you have to keep yourself from kissing the steering wheel.

 

[ac427cobra]

This car actually belongs to a friend of mine. I know the shop and person that did the work. This car has close to 75K in mods with under 10k on the odometer. He actually tracks this car, and now has a new Shelby that he is doing some crazy work too.

Anyhow, this brake kit was actually designed for Panoz. It bolts right up to an IRS system, and requires some serious upgrades if its a stick axle. It is actually two brake kits. It is a 13" Brembo Grand Touring kit, and the small caliper is by Mclaren and is used for parking brake only. For a stick axle application, you would need a torsen diff, new axles, and a specific bracket that the unnamed shop had designed specifically for this Mach 1.

I have driven this car once, and I can tell you, when you hit the brakes hard, it stops like a roller coaster. It takes all you have to keep yourself from kissing the steering wheel.

Although that rear brake set-up may 'look' cool and stop well, it goes against most principals of 'increasing' performance. :read:

Performance minded people are always looking for ways to reduce unsprung weight along with reducing rotating mass. Not bolting on a caliper that weighs twice as much as the OEM, having to add an additional second caliper for an emergency brake and adding approximately 9# for a pair of those big honking ass 1.100" thick 13" rear rotors!!! :idea: People spend $500 PER WHEEL (and more) to reduce rotating mass 4.5# on each corner of their car.

The OEM rear Cobra rotor weighs 11.7#

The 1.100" thick 2 pc rear rotor weighs approximately 16.1#

Someone might do that for a 'looking cool' factor but I doubt you'll find anyone doing that to 'increase' actual performance.

FWIW

:thumbsup::coolman::beer: