Brakes?

94slowbra1

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the front is by far the meat of the braking system.
yes i am limited to 18" wheels up front and 17s out back once i throw the 13" kit on. my car isnt set up for drag racing so a nice 17" wheel with a decent tire will work for me if i want something to grip. i am very stable at high speeds and want my brakes to be ready when i need them. no drag set ups for me
 

ac427cobra

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Bruce whats your take on the 2000 cobra R front brake kit? I had that on my 2003 cobra vert. Was night and day for braking performance. I always thought the stock 03/04 cobra brakes were very under performaning for the speed and weight it had.

The 13" Y2KR 4 piston Brembos are a very nice upgrade over the 13" OEM Cobra 2 piston floating PBR calipers. You have to remember that auto manufactures only spend the minimum amount of cash layout when it comes to brakes, suspension or even creature comforts for that matter. If you want the 'good stuff' you have to opt for the better/higher performance model or performance options, otherwise you're just going to get the bare minimum. The four piston Brembo calipers are infinitely more efficient than the PBR calipers because not only do they have twice as many pistons, they also don't have to rely on a poor floating caliper design to stop the car. This translates into more clamping power for the pads on the rotor with less pedal effort at the same time. In addition, when you hammer on the brakes you will feel a significant difference in your seat of the pants 'dyno'. Floating calipers are fine on the front of your mom's or your wife's grocery getting mini-van but not on something you would call a performance car. This is why high performance cars today have a fixed four, six or more piston caliper on the front of the vehicle. Look no further than Shelby, Corvette, or Porsche brakes and you'll see what I'm talking about.
 

ac427cobra

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i dont have any factual data, cones, measurements ect... but i would definitely say yes. my car reels back in very quick. to me the braking confidence and feel is the best part about the 14" set up. it never feels like its on the edge, i just seems easy

You are one of the few Mustang guys that can truly appreciate the braking efficiency of the 14" front Brembo brake kit because you have personally experienced it. That kit is one of my three favorite mods to my SN-95 vehicles.

once broken in i noticed a big difference when laying into the brakes. they are down right violent when warm and you stab them. paired with good pads, good fluid and stainless lines.

"Down right violent" is a pretty good description comparing that 14" front Brembo kit to the 13" OEM PBR set-up! I just hope it doesn't scare some people! LOL

i cant see a better set up except for maybe adding his 13" rear kit to compliment it.

Our 13" rear kit is a very nice compliment to the 14" fronts. But the change in braking will be significantly more subtle than what you experienced on the front.

if you do eventually step up to a bigger rotor i highly suggest a 2pc design. a 1pc 14" rotor is going to be heavy

We put this 14" Wilwood kit together for Mustang people that are on a budget. Hence the one pc rotors included in the kit. We are working on some variations of 2 pc rotors but that is honestly going to add about $650.00 to the price of the kit. They will be available in three weights, light weight drag race, street and heavy duty road race.
 

Avispa

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Don't want to hijack the thread, but what would be a good choice for keeping 13" front rotors so stock SVT wheels will fit? Would any of the 4 or 6 piston aftermarket kits or the Cobra R conversion give a seat of the pants improvement in braking over the stockers?
 

ac427cobra

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Don't want to hijack the thread, but what would be a good choice for keeping 13" front rotors so stock SVT wheels will fit? Would any of the 4 or 6 piston aftermarket kits or the Cobra R conversion give a seat of the pants improvement in braking over the stockers?
The Cobra R 13" front brakes are a nice upgrade over the OEM 2 piston floating PBR Cobra calipers. You will definitely feel a difference in braking efficiency.
 

Avispa

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Thanks! That's exactly what I needed to know. The answer seemed intuative, but you can't substitute actual experience. No point in spending the $ if there isn't going to be a noticeable benefit.

Just to clear up a couple of things in the thread, if by "braking efficiency" you mean braking force with respect to pressure on the brake pedal, yeah if everything else is equal, 4 piston calipers will brake harder for the same pedal pressure (and resulting brake fluid pressure) as 2 piston, depending on the total piston area for each kind of caliper. It looks like the Cobra R calipers have four pistons that are about the same size as the 2 pistons in the PBR calipers, so the clamping force would be about twice that for the same fluid pressure in the Corbra R caliper as the PBRs. Is that gonna mean the proportioning valve needs to be changed? The factory set it up proportioning for the relative braking force front/rear for the calipers and rotors actually used. Seems like the car is going to dive under hard braking unless the rear brakes get increased fluid pressure for the same amount of pedal force - unless the required increase in brake fluid volume to the front balances things out. Any comment on that?

If you mean the Cobra R brakes give total higher braking torque that can by applied to the rotor, no. Total braking torque depends on surface area of the brake pads, where relative to the center of rotation on the rotor the pad area is and the coefficient of friction between the pad and the rotor surface. So yeah, for the same pad area and caliper force, putting the pad area on the outside of a 14 inch rotor will give more torque than a similar setup on a 13 inch rotor. A Cobra R caliper won't have twice the maximum braking torque of a stock 2 piston PBR caliper. If by "clamshell" you mean the caliper tends to spread apart when clamped, that by itself isn't related to whether the caliper has pistons on one side or both. On one-sided calipers, the clamping force generates the same reactive force on the other side of the caliper. It's the total force that spreads the caliper, not where it comes from. If you mean the Cobra R calipers have a thicker bridge between sides, that's another matter altogether.

Thanks again!
 

04torchred

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The Cobra R 13" front brakes are a nice upgrade over the OEM 2 piston floating PBR Cobra calipers. You will definitely feel a difference in braking efficiency.

The only negative to the Cobra R kit is the rotor is still the same thickness as a stock rotor so when its heated on the track they will still warp quickly like the OEM rotor does?

The 13" Brembo kits and Stoptech all run a thicker rotor so you should get improved rotor life at the track is my understanding even if you don't go up to a 14" kit(for people that really want to stay on 17's)
 

ac427cobra

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The only negative to the Cobra R kit is the rotor is still the same thickness as a stock rotor so when its heated on the track they will still warp quickly like the OEM rotor does?

The 13" Brembo kits and Stoptech all run a thicker rotor so you should get improved rotor life at the track is my understanding even if you don't go up to a 14" kit(for people that really want to stay on 17's)

The OEM 13" Brembo one piece rotors, even at the 28mm thickness are actually quite stout and will suit the needs of 95% of the people running them. The same rotors are used for the Y2KR 13" kit and the 13" OEM PBR floating 'Cobra' calipers. They will even suit about 85-90% of the people running these rotors on track.

However, if you are looking to make a significant brake upgrade for your SN-95 vehicle, the 14" kit really is the way to go.
 

99 KOBRA

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I'm on my second set of Stop Tech 13" two-piece front vented rotors. I wore out the first set and they never warped or needed turning.
 

04torchred

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The OEM 13" Brembo one piece rotors, even at the 28mm thickness are actually quite stout and will suit the needs of 95% of the people running them. The same rotors are used for the Y2KR 13" kit and the 13" OEM PBR floating 'Cobra' calipers. They will even suit about 85-90% of the people running these rotors on track.

However, if you are looking to make a significant brake upgrade for your SN-95 vehicle, the 14" kit really is the way to go.

Good to know I had just heard of people who put frequent heat into the 28mm rotors vs the 32mm that they were consumed far quicker. That was from a tech guy at brembo, but who knows if they actually had Cobras and raced them to back up that statement.
 

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