Brake kits

[A4_cabrio]

I was wondering what would a reasonably priced solution would be to improve my stopping power of my A4

I was looking at this kit:

http://www.ecstuning.com/Audi-B7_A4-Quattro-2.0T/Braking/Big_Brake_OEM/ES4523/

Any thoughts or other recommendations ?

[joker_2.0]

I have that, its great, add in some stainless steal brake lines and some good pads and you're set.

[mec]

S4 brakes , or 18z

[moyenecorniche]

Increasing your rotor diameter size isn't going to do anything other than separate you from $400. You'll still be using the stock caliper which means your braking strength will be the same as before..... better rotors and better pads will improve braking performance, but just moving the caliper outward and increasing rotor size is not worth the expense.. it is mostly cosmetic...

Do upgrade rotors and pads but the only reason to add that bracket would be if/when you went to a better caliper than the stock A4 such as a 4 or 6 piston ( Porsche / Brembo ) then you would need larger rotors....
But for now... just get better rotors and pads.... A much better cost to performance value.

As for the S4 Caliper.... It is a single piston caliper, unless you can source an entire kit ( rotors/calipers/ss lines ) for $500 or less than that would be a justifiable cost for performance, but if not just hold on until you can spec a BBK for a bargain.... It's possible, they are out there...

[A4_cabrio]

You're totally right. It would actually make the car brake worse - due to the potential increased weight. I hadnt noticed it didn't come with S4 calipers. I guess I was expecting too much for under 400 bucks. So maybe choose a pair of rotors some ceramic pads - I liked the Akebono I put on my Z4 shortly before the car got totaled. Great once warmed up but a little scary at the first application ;-)



Increasing your rotor diameter size isn't going to do anything other than separate you from $400. You'll still be using the stock caliper which means your braking strength will be the same as before..... better rotors and better pads will improve braking performance, but just moving the caliper outward and increasing rotor size is not worth the expense.. it is mostly cosmetic...

Do upgrade rotors and pads but the only reason to add that bracket would be if/when you went to a better caliper than the stock A4 such as a 4 or 6 piston ( Porsche / Brembo ) then you would need larger rotors....
But for now... just get better rotors and pads.... A much better cost to performance value.

As for the S4 Caliper.... It is a single piston caliper, unless you can source an entire kit ( rotors/calipers/ss lines ) for $500 or less than that would be a justifiable cost for performance, but if not just hold on until you can spec a BBK for a bargain.... It's possible, they are out there...

[drumnjuny]

i disagree. if you move the caliper further from the center of the hub, that is an increased surface area that it is hitting per rotation of the wheel. The reason it doesn't come with S4 calipers is that they're the same as ours, if i'm not mistaken.

so actually, that kit would increase your stopping power due to the carrier upgrade, as well as the coefficient of friction being higher with upgraded rotors. I wouldn't suggest getting it for $400. but you can surely pick up the carriers off of a totalled S4 for 50$, and buy a set of whichever rotors you want for $150-200...

you can also buy a full S4 brake set off a totalled car for like $500 lol. including the calipers. but that will be used rotors, i would try to find the calipers and carriers off a totalled car and buy new pads and rotors if you're really into it. probably cost you about the same $4-500


if you go BBK, beware it is hard as F to find wheels that fit over them without spacers.

[Mister W]

Call it snake oil, but I do find I have better braking with that setup. I felt the rotating weight difference too tho.

Sent from my Nexus 7 using Tapatalk

[Charles.waite]

i disagree. if you move the caliper further from the center of the hub, that is an increased surface area that it is hitting per rotation of the wheel. The reason it doesn't come with S4 calipers is that they're the same as ours, if i'm not mistaken.

so actually, that kit would increase your stopping power due to the carrier upgrade, as well as the coefficient of friction being higher with upgraded rotors. I wouldn't suggest getting it for $400. but you can surely pick up the carriers off of a totalled S4 for 50$, and buy a set of whichever rotors you want for $150-200...

you can also buy a full S4 brake set off a totalled car for like $500 lol. including the calipers. but that will be used rotors, i would try to find the calipers and carriers off a totalled car and buy new pads and rotors if you're really into it. probably cost you about the same $4-500


if you go BBK, beware it is hard as F to find wheels that fit over them without spacers.

Agreed.

Now having said that the overall stopping distance won't change. Getting better tires is the only thing that will noticeably affect stopping distance (unless you're on a racetrack).

That ECS kit is decent' You get the larger 345mm rotors from the S4 and the larger carriers from the S4, making your front brakes the same as the S4. Honestly I doubt you'll notice much of a difference. Get better pads (Hawk HPS, Akebono Ceramic, etc), stainless lines, and a Tyrolsport caliper stiffening kit before you bother upgrading to the S4 fronts. $400 is a lot for a 24mm larger rotor...

[drumnjuny]

yeah your money is definitely better spent on pads and SS lines

[LoKisSpYdR]

yeah your money is definitely better spent on pads and SS lines

Agree with everything CP and Arjun said.

[Xaero]

Increasing your rotor diameter size isn't going to do anything other than separate you from $400. You'll still be using the stock caliper which means your braking strength will be the same as before..... better rotors and better pads will improve braking performance, but just moving the caliper outward and increasing rotor size is not worth the expense.. it is mostly cosmetic...



This is pretty much dead wrong. Basic physics proves that moving a caliper further away from the axle proportionally increases stopping power.

The equation is Torque = Force x Distance.

Torque is what we are slowing the car down with.
Force is the amount of friction between the pad and rotor.
Distance is how far from axle center-line the brake pad is.

[Xaero]

Increasing your rotor diameter size isn't going to do anything other than separate you from $400. You'll still be using the stock caliper which means your braking strength will be the same as before..... better rotors and better pads will improve braking performance, but just moving the caliper outward and increasing rotor size is not worth the expense.. it is mostly cosmetic...



This is pretty much dead wrong. Basic physics proves that moving a caliper further away from the axle proportionally increases stopping power.

The equation is Torque = Force x Distance.

Torque is what we are slowing the car down with.
Force is the amount of friction between the pad and rotor.
Distance is how far from axle center-line the brake pad is.

[aluthman]

This is pretty much dead wrong. Basic physics proves that moving a caliper further away from the axle proportionally increases stopping power.

The equation is Torque = Force x Distance.

Torque is what we are slowing the car down with.
Force is the amount of friction between the pad and rotor.
Distance is how far from axle center-line the brake pad is.

You beat me to it. In addition to the increased area mentioned above, it basically increases "leverage" applied by moving the caliper away from the hub. Same principle as using a cheater bar to break something loose. You may not be able to break a bolt loose with a 12" long wrench, but add a 3 ft cheater bar to it and the same force applied to that will pop it free easily (or snap the bolt off). Same thing happens with your brakes, only we're talking a few mm instead of inches or feet. Stopping distance however will only improve if your tires can handle it. If your ABS is going nuts because the tires are at their limit, no increase in braking will make you stop faster.

That being said, you would probably be happy with new rotors, good pads, SS lines, and fresh fluid. The B7 has pretty good brakes from the factory.

[pule333]

I believe this is the best value for money BBK for our cars! And possible to find for around 500.
http://img.tapatalk.com/d/14/01/22/a6ynybe2.jpg

[moyenecorniche]

Moving the caliper outward on a bigger rotor does not increase the caliper's footprint ( so to speak )... Since it is the same caliper, it retains the same pad area of pressure. No gain there..
Speaking of physics.... If the equation ( Torque = Force x Distance ) applies...... and the analogy of the pry bar being lengthened .... Neither apply for this application..

(1) the caliper is relocated outward... But the mechanics are the same.. The piston is still pressured by hydraulics, none of the calipers mechanicals have changed, there is no increased leverage being applied by outward relocation as far as the caliper is concerned... It is still fluid being pushed thru a hose...
For sake of the argument.... If in it's stock location the caliper is pressuring @ 200lb / psi , moving it outward 20mm will not change it's operation.

(2) because none of the leveraging forces on the piston have changed, the prybar analogy also doesn't apply..

I will agree to other forces entering the equation such as increased friction and heat resulting from a faster rotating surface due to an increased distance from the hub center...
But wether that results in better grip from the pads due to increased heat is open to debate....

Just the replacement of new pads and rotors will improve braking.... I'm not convinced of the outward relocation method resulting in justifiable brake performance increase...
When the most important components ( caliper/pistons ) have not changed.... Nope... expensive upgrade with questionable results....

[mec]

I believe this is the best value for money BBK for our cars! And possible to find for around 500.
http://img.tapatalk.com/d/14/01/22/a6ynybe2.jpg

For the calipers perhaps. but then you have to buy rotors and pads, hardware, lines, it adds up...

[aluthman]

Moving the caliper outward on a bigger rotor does not increase the caliper's footprint ( so to speak )... Since it is the same caliper, it retains the same pad area of pressure. No gain there..
Speaking of physics.... If the equation ( Torque = Force x Distance ) applies...... and the analogy of the pry bar being lengthened .... Neither apply for this application..

(1) the caliper is relocated outward... But the mechanics are the same.. The piston is still pressured by hydraulics, none of the calipers mechanicals have changed, there is no increased leverage being applied by outward relocation as far as the caliper is concerned... It is still fluid being pushed thru a hose...
For sake of the argument.... If in it's stock location the caliper is pressuring @ 200lb / psi , moving it outward 20mm will not change it's operation.

(2) because none of the leveraging forces on the piston have changed, the prybar analogy also doesn't apply..

I will agree to other forces entering the equation such as increased friction and heat resulting from a faster rotating surface due to an increased distance from the hub center...
But wether that results in better grip from the pads due to increased heat is open to debate....

Just the replacement of new pads and rotors will improve braking.... I'm not convinced of the outward relocation method resulting in justifiable brake performance increase...
When the most important components ( caliper/pistons ) have not changed.... Nope... expensive upgrade with questionable results....

[headbang]

Prybar analogy does apply, you just aren't looking at it correctly. If I wasn't on my phone, I'd draw a picture.

[drumnjuny]

Moving the caliper outward on a bigger rotor does not increase the caliper's footprint ( so to speak )... Since it is the same caliper, it retains the same pad area of pressure. No gain there..
Speaking of physics.... If the equation ( Torque = Force x Distance ) applies...... and the analogy of the pry bar being lengthened .... Neither apply for this application..

(1) the caliper is relocated outward... But the mechanics are the same.. The piston is still pressured by hydraulics, none of the calipers mechanicals have changed, there is no increased leverage being applied by outward relocation as far as the caliper is concerned... It is still fluid being pushed thru a hose...
For sake of the argument.... If in it's stock location the caliper is pressuring @ 200lb / psi , moving it outward 20mm will not change it's operation.

(2) because none of the leveraging forces on the piston have changed, the prybar analogy also doesn't apply..

I will agree to other forces entering the equation such as increased friction and heat resulting from a faster rotating surface due to an increased distance from the hub center...
But wether that results in better grip from the pads due to increased heat is open to debate....

Just the replacement of new pads and rotors will improve braking.... I'm not convinced of the outward relocation method resulting in justifiable brake performance increase...
When the most important components ( caliper/pistons ) have not changed.... Nope... expensive upgrade with questionable results....

so is the pressure on the disk the stopping force? or is the torque on the wheel? and it does increase the surface area of the rotor that the pad is in contact with

you're a funny guy doe

[Charles.waite]

Also the increased swept area from the larger rotor makes a difference. the increased weight allows for more heat absorbtion and the greater surface area disperses heat more effectively.

None of this will give you greater clamping pressure, but nobody was arguing that. Braking is about creating friction, turning it into heat, and dispersing the heat as efficiently as possible. More clamping pressure will just cause ABS to kick in sooner, which really does nothing. If the OEM single-pot caliper doesn't reach its threshold under normal or extreme (Autocross for instance) conditions, which I'd wager it doesn't, then more/larger pistons are pointless. The pads and the rotors matter more than the calipers when your calipers are as good as ours are stock.

You should have driven my b6 before I upgraded to B6 S4 brakes (same as B7S4). The stopping distances likely haven't changed but the braking feel is so so so muchbetter. It was absolutely terrifying before, and my fluid was in good shape. Just driving my b6 and b7 back to back was night and day different.

I will argue this till the sun goes down, but pads are more important than anything else for the b7. The b6's brakes were god awful though and a full system upgrade was necessary. There are a shitload of variables affecting braking. And there are a shitload of subjective criteria that each person uses to judge "better" brakes. Some people LOVE pads with bite. Others love more linear pads that require a bit more pedal effort but have a more progressive feel. Some people love to spend $5k on a BBK because racecar even though the only place where you will find measurable benefits to a massive Brembo BBK are on a racetrack where the systems ability to dissipate heat is what matters most.

If you want shorter stopping distances, get better tires. If you want better brake feel, get better pads and possibly stainless lines and a brake stiffener kit.

All this arguing using misinterpreted physics is amusing though by all means lets continue the discussion...

[:D]

[Operator]

For the calipers perhaps. but then you have to buy rotors and pads, hardware, lines, it adds up...

THIS!!!! An your choice of wheels goes down....

[Operator]

OP check out EBC Redstuff pads, ABT D&S rotors, Goodridge SS lines, and some Pentosin Racing brake fluid, it's a nice bang for your buck upgrade. Add some caliper paint if you want some Pizzazz.

[J.Owen]

this thread makes my head hurt.

[eMacPaul]

Moving the caliper outward on a bigger rotor does not increase the caliper's footprint ( so to speak )... Since it is the same caliper, it retains the same pad area of pressure. No gain there..
Speaking of physics.... If the equation ( Torque = Force x Distance ) applies...... and the analogy of the pry bar being lengthened .... Neither apply for this application..

(1) the caliper is relocated outward... But the mechanics are the same.. The piston is still pressured by hydraulics, none of the calipers mechanicals have changed, there is no increased leverage being applied by outward relocation as far as the caliper is concerned... It is still fluid being pushed thru a hose...
For sake of the argument.... If in it's stock location the caliper is pressuring @ 200lb / psi , moving it outward 20mm will not change it's operation.

(2) because none of the leveraging forces on the piston have changed, the prybar analogy also doesn't apply..

I will agree to other forces entering the equation such as increased friction and heat resulting from a faster rotating surface due to an increased distance from the hub center...
But wether that results in better grip from the pads due to increased heat is open to debate....

Just the replacement of new pads and rotors will improve braking.... I'm not convinced of the outward relocation method resulting in justifiable brake performance increase...
When the most important components ( caliper/pistons ) have not changed.... Nope... expensive upgrade with questionable results....

The torque in this case is the frictional force applied by the pads to the rotor, multiplied by the distance from the center at which that force is applied. Even if the brake pad/rotor combo has the same friction coefficient as the original combo, if the distance it is applied from the center is increased, the stopping torque applied to the wheels is increased.

[swoardrider]

I was wondering what would a reasonably priced solution would be to improve my stopping power of my A4

I was looking at this kit:

http://www.ecstuning.com/Audi-B7_A4-Quattro-2.0T/Braking/Big_Brake_OEM/ES4523/

Any thoughts or other recommendations ?

In layman's terms, the increased torque and friction of this kit needs to exceed the drawback of increased weight of a larger rotor. I'm going out on a limb here to say that Audi designed the S4 brakes to stop a heavier, more powerful B7 chassis. Assuming Audi did their homework, this kit should stop your lighter, less powerful car quicker. But, these are not OEM S4 rotors. These are aftermarket. Therefore the friction needs to be at least the same as an OEM S4 rotor for my statement to be 100% accurate. I'm assuming ECS did some testing before they marketed this products as an improvement. If not, shame on them. The better option may be to increase torque/friction, while decreasing weight. Something like this is stock size:http://jhmotorsports.com/shop/catalog/front-rotorspair-jhm-piece-lightweight-for-b5-s4c5-a6b7-a4-p-349.html?cPath=21_62_65_244_252 Or this:http://www.racingbrake.com/AUDI-S4-QUATTRO-FRONT-99-02-A6-2-7L-TURBO-FRONT-p/2021.htm