This is for 94-04 cars only!!

OK so the big thing is to upgrade to cobra brakes to get the 13" rotor with dual piston calipers. Now my car is getting to the point where i need to upgrade or freshen up the stock brakes. So i wanted to see how the stockers compair to cobra brakes.

Stock GT brakes on a coupe stop the mustang in 135 feet from 60mph.
Stock 2003-2004 cobra brakes do it in 116 feet from 60mph.

Thats a 19 foot difference, which is just over the length of your car (about 16 feet total for us), but still a large improvement.

Bullit kits are listed as 125 feet from 60mph. Even less of a difference. This is due to the bullit not having the exact same caliper as the 03-04 cobra which is said to have bigger pistons and gives more stopping power.

So considering all of this is it worth it to upgrade for a mear 10-19 feet of stopping power?

I think so, it gives you over an entire nother length of your car plus some with the 03-04 cobra kit. This could be the difference of a truck rear end or stopping and not hitting them.

Now some of the difference comes from the fact that the cobra,bullit,mach1 cars have 13" rotors, which give you more levrage to stop the car. Here are stock Sizes for all cars.

99-04 GT rotors are 10.8" Front and 10.5" rear
03-04 Cobra's are 13" front and 11.65" rear.
Bullit rotors are 13" front Cobra Spec Rear.
Mach 1's are 13" front Cobra Spec Rear.

The cobra's do have larger rear rotor's but the gain in stopping distance is none. The biggest benifit is the vented rotor (unlike all other cars) and the larger rotor cools off faster and make brake fad less.

When upgrading to 13" new front rotors you will need the fallowing:
13" rotors (two)
2 new calipers (this is where cobra,bullit,mach1 comes in)
2 cobra,bullit,mach1 brake lines (Gt will not work)
New Caliper brakets (GT will not work with new calipers)
New Banjo Bolts for calipers.

Of course you can buy these all used also. Most kits are anyhwere from $360-$450 new for front kits.

For the Rear Cobra rotor upgrade all you need is as fallows:
new 11.65" rotor (two of them)
New caliper mounting braket (two again)
thats it.

Any more info anyone has please share. I wanna make this into a starting point for brake upgrades and possibly a sticky.

READ DOWN FOR MORE INFO ON BRAKES

 

Interesting. Would it be safe to assume that 03-04 conversion to a GT would perform better than a stock Cobra because of the difference in weight? With the GT being lighter. Of course when I say perform that's in regards to stopping distances.

 

Yes you would assume so since you are likely what 300lbs lighter or more? Not sure what the 02 GT's weigh; plus you have alot less weight on the nose of your car than I do on my 03 cobra.

I upgraded to Ferodo pads and that was a huge difference from the stock pads not to mention I am adding stainless brake lines to the front which will help with feel and provide even better performance.

Alot of people open track with the 03-04 cobra front brake setup since it is an outstanding system for likely 90% of the mustang population outside of the very serious open trackers that will go with a 4 or 6 piston setup. The right pad choice and stainless lines make a HUGE difference as well.

 

Spike the only thing I can add is that you cant really compare them car to car as they all weigh different weights, and all have completely different suspension setups. You should notice a nice difference though as you have a lighter car than the cobra, and Ive heard its a great upgrade anyhow. I would suggest you get stainless lines and Hawk or a better than stock (not autozone-trust me) pad. Ive thought about the upgrade, and maybe Ill do it if I keep the car for a long time, but I dont know that I need it, but who knows. Maybe in January...

 

IMO Big breaks = good looks

and nothing more..it's not worth it

 

Just as Spike said, 19 feet could be the difference between you rearending some one or not. IMO the bigger breaks not only = good looks but also seem like a good insurance policy! "I just saved a bunch of money by switching to 03-04 Cobra brakes!, uh I mean GEICO!" LOL!

 

no way... i noticed a huge difference in how fast my car can stop when i changed my brakes. it was definitely worth the money. especially if you do any kind of racing events like autox or road courses, which i love to do. the stock brakes just cant hold up in that kind of environment. thats the whole reason i had to change them in the first place.

 

Not only are the upgrade well worth for the purposes mentioned above but if I can improve my car's ability to stop then why not? Also have to remember that the engineers that designed our cars used the breaks they chose for a reason. Cobras are considerably faster than GT's so therefore,among other reasons, they have a better brakin system. Once you start modding the car for speed then I think it'll be a good idea to mod the brakes to help it stop. One hand washes the other.

 

from my stock gt rotors, calipers, and pads all around then changing to 10th ann cobra front and back rotors, calipers, and pads, with SS lines, I noticed a huge difference. Next time around I need brakes, itll be probably be hawk pads and probably some powerslot rotors.

 

i did the khobra upgrade...deff worth it!

 

Ive had my brakes become useless at a road course (Road America). Imagine how your bowels move trying to brake from the 3 in a 5 sign corner approaching a 70 degree turn and 3 cars tail to tail at about 50 mph. Yeah, it sure isnt a good feeling.

Upgraded brakes are a GREAT thing to have. Im very glad I upgraded to the 10th ann cobra package with SS lines, and dont regret the purchase one bit.

 

Yea, Id never go so far as to say upgraded brakes are a waste. I dont care if I never went on a road course, its still worth it with the crappy brakes our cars come with stock.

 

i think our brakes are prety damn good stock.

As for the weight issue a 99-04 GT coupe weights ruffly 3317lbs. (no mach 1000 stock non bullit wheels.) a cobra weights in at 3664lbs.

Which i forgot to mention. So the Cobra brakes, depending on avaliable traction will stop you even faster.Because of the factr our cars weight less, give or take your options.

On anthoer note. The size od tire and traction you have play a big role, by simply going to somewhat larger tire say 255 or stock 245 can also help brakeing by giving a larger contact pacth for the tire to grabe the road. This is also another key point. You can only brake as hard as traction permits.

I am not here to talk about modding my car by the way i was looking for solid good info on aftermarket or upgraded brakes for others to see.

 

Sorry i made that comparison of our brakes sucking by comparing it to my moms pontiac G6's brakes. To me, Mustang brakes feel slow responsive, where as her car damn near breaks your neck when you stomp em. Now, I may look at a G6's numbers and see the mustang outperforms it, but im basing it off of feeling. Carry on

 

Here is a good Link with info on Mustangtuning.com on rotors,pads,stainless steel lines etc..

https://mustangboards.com/redirect-t...guide-101.html

 

Everyone needs to understand that brakes work similar to a wrench.

If you have small rotors with a large number of calipers, you wont be doing any better than if you had a small rotor with a single piston caliper. Why is this?

Think of the center of the axle where the rotor bolts up as a rusty nut. Now, when you get a REALLY rusty nut that just wont seem to budge, how do you loosen it? Do you take the shortest socket and wrench you have and try to break the nut loose? Or do you get a breaker bar and go from a further distance away?

You should be getting a breaker bar and going from a further distance away. You can put more force on the nut if you are pushing from further away than if you are closer to the nut.

Same holds true with a rotor. Think of the diameter of the rotor as your wrench. Smaller rotor = closer caliper to the center = less torque applied = longer stopping times. On the contrary, larger rotor = caliper further away = more torque applied = shorter stopping times.

 

Yeah i was getting to that point thank you chris.

ALso i got rid of some posts to clean up the thread, like side talk and other random convo's that were going on.

 

First get the car to stop, then get the car to go! I went with the Mach brake upgrade with the SS lines (liked the running stang on the side) and I noticed a huge difference in stopping power. Make sure you break the brakes in properly or you'll warp your rotors. They had a great write up in one of the mustang magazines about marrying your pads to your rotors. Can't seem to find it but if someone knows the link, throw it in!

 

I think the only reasons to upgrade brakes are A) looks, or B) if you auto-x etc

Saying that a car needs better brakes because it has more hp is not good logic, a car is going to stop just as fast if you have 100hp or if you have 1000 hp, your 60-0 will not change. So if your stock brakes were good when you were stock, then they are just as good now, no matter how much power you have (assuming your going just as fast when your stopping)

and as spike said, your can only stop as fast as traction permits, i dont care if you have brembo brakes 10piston calipers whole nine yards, if your running bald 195's in the front your not going to stop nearly as fast as a guy with stock brakes and 245's. better tires > better brakes


It was mentioned that a cobra upgrade kit might be the diffrent between rearending that truck or not, but being an aware and responcable driver is far more important than good brakes. Nothing can replace being a good driver and being aware of your surroundings.

oh and big brakes will make you go slower (more weight = SLOWSTANG)

 

I think the only reasons to upgrade brakes are A) looks, or B) if you auto-x etc

Saying that a car needs better brakes because it has more hp is not good logic, a car is going to stop just as fast if you have 100hp or if you have 1000 hp, your 60-0 will not change. So if your stock brakes were good when you were stock, then they are just as good now, no matter how much power you have (assuming your going just as fast when your stopping)

This is true, but a car with 10 times more power is gonna most likely be braking 10 times harder. So yes you'll need something more than just your stock brakes

and as spike said, your can only stop as fast as traction permits, i dont care if you have brembo brakes 10piston calipers whole nine yards, if your running bald 195's in the front your not going to stop nearly as fast as a guy with stock brakes and 245's. better tires > better brakes

I'll leave this alone as i agree 100%

It was mentioned that a cobra upgrade kit might be the diffrent between rearending that truck or not, but being an aware and responcable driver is far more important than good brakes. Nothing can replace being a good driver and being aware of your surroundings.

Nothing can replace being a good driver is true. But fact is we all make mistakes and i would much rather have a 6 piston big brake kit from anyone rather than a single or 2 piston stock kit

oh and big brakes will make you go slower (more weight = SLOWSTANG)
This is asinine, its like saying adding a blower will add more weight and slow you down...Its a necessity to upgrade your brakes as they are the most under rated thing!

 

So would you assume that a mustang with 100 HP weighs the same as one that is pushing 1000 HP? Sure with todays technology (carbon fiber, aluminum) you can get hellified HP and lighten the car up at the same time. But it's proven, the stopping distances with stock GT brakes and Cobra upgrades are different. For the most part beefin' up the engine, tranny, etc. your gonna be heavier.

Some one mentioned previously that more contact surface from bigger tires help brake also which is true. bigger rotors and pads relate to this as well. More surface area on the larger rotor for the larger pad to grab.

Sure being an aware and great driver can prevent you from rearending someone but accidents happen. That's why they are called "accidents".
Besides what about the "other" guy? The guy that's doing 60 in front of you and slams on his brakes (he has Cobra upgrade by the way) and you slam on yours with your stockers. Then what happens?

 

This is true, but a car with 10 times more power is gonna most likely be braking 10 times harder. So yes you'll need something more than just your stock brakes

what does braking harder have to do with anything? assuming all things are equal (tires wieght dist etc) the cars are going to stop just as quickly if the only diffrence is horsepower. I only argue this point to combat the people that say you need bigger brakes when you have more horsepower when in fact the two are unrelated.


Nothing can replace being a good driver is true. But fact is we all make mistakes and i would much rather have a 6 piston big brake kit from anyone rather than a single or 2 piston stock kit

I suppose on an ABS car, but my car only stops as fast as it stops when the tires are locked up, doesnt matter if the tires locked up with 4 pistons or 1.


This is asinine, its like saying adding a blower will add more weight and slow you down...Its a necessity to upgrade your brakes as they are the most under rated thing!

how much weight do you think each roter adds? if going from say v6 brakes to cobra brakes maybe you gain ~10lbs total from all 4? (im just guessing) thats about .1 in the 1/4 mile. And blower vs. brakes is a horrible comparrason. a blower adds power, brakes in no way make you faster or add any power (all they can do is slow you down.)

 

"So would you assume that a mustang with 100 HP weighs the same as one that is pushing 1000 HP? Sure with todays technology (carbon fiber, aluminum) you can get hellified HP and lighten the car up at the same time. But it's proven, the stopping distances with stock GT brakes and Cobra upgrades are different. For the most part beefin' up the engine, tranny, etc. your gonna be heavier."

Now your talking wieght, not horsepower, when was the last time someone said "oh well your car weights more now, you better get big brakes"

no, people allways say "man you better upgrade your brakes with that much hp"

 

So do you think the engineers that put the Cobra together used those breaks just cause they look nice? honestly?

 

And eventually stop. Exactly. that's what they are supposed to do. You know what? Why not try to "upgrade" your brakes by modding and installing some Honda Civic brakes. I'm sure that they are smaller and lighter so you'll go a lot faster.

 

I think they put those brakes on there because

A) the car is heavier, if it has stock GT brakes it wouldnt stop as fast as a stock GT

B) They put them on there in part im sure because it is what is expected, immagine the buyer when he was told that his 3Xk$ cobra has the same brakes as the 2Xk$ GT With better brakes they can justify a higher price tag

and
C) they look good

 

if i could find some brakes that are of the same quality as stock but are lighter i would, but im not going to spend money and put forth the effort for honda civic brakes. However, i bet Civic brakes would stop just about as fast as my stock brakes.

Lets face it, on a car without ABS, all brakes can do is lock up the tires, so it doesnt matter what brakes you have on your car as long as it can lock up the tires

 

LMAO, i'm not gonna go back and forth!

 

This is not true. What if I have a stock mustang GT racing in the 1/4 against a stock mustang GT with a built motor. The only difference between these 2 cars is the fact one engine is making 600RWHP the other is making 250RWHP and they both have the factory brakes. Now when the car that has 600RWHP crosses the finish line and starts to apply its brakes its stopping distance will be alot further than the stock 250RWHP GT from the sheer fact one car just crossed the traps at well over 130mph and the other one crosses at 100mph. The fact of the matter is the higher HP car gets to its speed in a much shorter distance(time and feet). Hence why the more HP you add to a car you should also add to braking capacity since you accelerate much faster in the same given distance so your stock binders wont cut the mustard.
Just my thoughts.

 

you are correct, a car going from 130-0 will take longer then 100-0, this is a no brainer. But that doesnt have to do with hp (other then you can get there faster with more hp)

a 600hp car will go from 60-0 as fast as a 200hp car

as far as the 1/4 mile goes, yes it will take you longer to stop trapping higher speeds, but for our cases (street cars) your not going to have a problem running out of track to stop.