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Old 05-28-2003, 08:56 AM   #1
Luke@tirerack
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Default Brakes ...

Thinking about new brake pads and rotors? Or a big brake kit that'll show through your new wheels?

First decide what feature(s) are most important to you:

-- cleaner wheels

-- less brake fade

-- less noise

-- increased stopping power

And then, at tirerack.com, select your vehicle and pick one or more of the performance categories we've developed to make it easy for you to buy the right products:

-- Premium

-- Performance Street

-- Autocross/Light Track

Let me know if you need product or performance recommendations and I'd be happy to help you out.

Link to brake page

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Old 05-29-2003, 05:19 PM   #2
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Default Rotors

Rotors ...
Slotted or drilled ????
slotted rotors maintain approx. 96% of the friction surface
drilled rotors maintain approx. 85-93% of the friction surface
drilled and slotted only maintain 80-91% of the friction surface

For many years most racing rotors were drilled. There were two reasons - the holes gave the "fireband" boundary layer of gasses and particulate matter someplace to go and the edges of the holes gave the pad a better "bite".

Unfortunately the drilled holes also reduced the thermal capacity of the discs and served as very effective "stress raisers" significantly decreasing disc life. Improvements in friction materials have pretty much made the drilled rotor a thing of the past in racing. Most racing rotors currently feature a series of tangential slots or channels that serve the same purpose without the attendant disadvantages.

the process of drilling rotors and slotting rotors was done for 1 reason and 1 reason only it is to disipate the gases that build up between the pad and the rotor which occurs under extreme heat ( when braking very aggressively like on a road course) and it has absolutely nothing to do with heat disipation. the only way to transfer more heat away is by using a larger heat sink which means use of a larger rotor whether in diameter or thickness. Since the caliper will only allow for a certain rotor thickness that solution is not very applicable because, if you are changing tha caliper opening width you might as well get a larger rotor diameter at that time

1) The brakes don't stop the vehicle - the tires do. The brakes slow the rotation of the wheels and tires. This means that braking distance measured on a single stop from a highway legal speed or higher is almost totally dependent upon the stopping ability of the tires in use - which, in the case of aftermarket advertising, may or may not be the ones originally fitted to the car by the OE manufacturer.

2) The brakes function by converting the kinetic energy of the car into thermal energy during deceleration - producing heat, lots of heat - which must then be transferred into the surroundings and into the air stream.

The amount of heat produced in context with a brake system needs to be considered with reference to time meaning rate of work done or power. Looking at only one side of a front brake assembly, the rate of work done by stopping a 3500-pound car traveling at 100 Mph in eight seconds is 30,600 calories/sec or 437,100 BTU/hr or is equivalent to 128 kW or 172 Hp. The disc dissipates approximately 80% of this energy. The ratio of heat transfer among the three mechanisms is dependent on the operating temperature of the system. The primary difference being the increasing contribution of radiation as the temperature of the disc rises. The contribution of the conductive mechanism is also dependent on the mass of the disc and the attachment designs, with disc used for racecars being typically lower in mass and fixed by mechanism that are restrictive to conduction. At 1000oF the ratios on a racing 2-piece annular disc design are 10% conductive, 45% convective, 45% radiation. Similarly on a high performance street one-piece design, the ratios are 25% conductive, 25% convective, 50% radiation.

3) Repeated hard stops require both effective heat transfer and adequate thermal storage capacity within the disc. The more disc surface area per unit mass and the greater and more efficient the mass flow of air over and through the disc, the faster the heat will be dissipated and the more efficient the entire system will be. At the same time, the brake discs must have enough thermal storage capacity to prevent distortion and/or cracking from thermal stress until the heat can be dissipated. This is not particularly important in a single stop but it is crucial in the case of repeated stops from high speed - whether racing, touring or towing.

4) Control and balance are at least as important as ultimate stopping power. The objective of the braking system is to utilize the tractive capacity of all of the tires to the maximum practical extent without locking a tire. In order to achieve this, the braking force between the front and rear tires must be nearly optimally proportioned even with ABS equipped vehicles. At the same time, the required pedal pressure, pedal travel and pedal firmness must allow efficient modulation by the driver.

5) Braking performance is about more than just brakes. In order for even the best braking systems to function effectively, tires, suspension and driving techniques must be optimized
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Old 05-29-2003, 05:20 PM   #3
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Default Brake Fade

Brake fade ... what is happening to my stopping power ???

there are a couple of causes of brake fade

#1.)
When the fluid boils in the calipers, gas bubbles are formed. Since gasses are compressible, the brake pedal becomes soft and "mushy" and pedal travel increases. You can probably still stop the car by pumping the pedal but efficient modulation is gone.

#2.)
Pad fade is when the temperature at the interface between the pad and the disc exceeds the thermal capacity of the pad, the pad loses friction capability due partly to out gassing of the binding agents in the pad compound. Pad fade is also due to one of the mechanism of energy conversion that takes place in the pad. In most cases it involves the instantaneous solidification of the pad and disc materials together - followed immediately by the breaking of bonds that releases energy in the form of heat. This cycle has a relatively wide operating temperature range. If the operating temperature exceeds this range, the mechanism begins to fail. The brake pedal remains firm and solid but the car won't stop. The first indication is a distinctive and unpleasant smell that should serve as a warning to back off.

In either case temporary relief can be achieved by heeding the warning signs and letting things cool down by not using the brakes so hard. In fact, a desirable feature of a good pad material formula is fast fade recovery. Overheated fluid should be replaced at the first opportunity. Pads that have faded severely should be checked to make sure that they have not glazed and the discs should be checked for material transfer. The easy permanent cures, in order of cost, are to upgrade the brake fluid, to upgrade the pads, or to increase airflow to the system (including the calipers). In marginal cases one of these or some combination is often all that is required.
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Old 05-30-2003, 12:03 PM   #4
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Default Warped Rotors

Directly from Stoptech ...

The term "warped brake disc" has been in common use in motor racing for decades. When a driver reports a vibration under hard braking, inexperienced crews, after checking for (and not finding) cracks often attribute the vibration to "warped discs". They then measure the disc thickness in various places, find significant variation and the diagnosis is cast in stone.

When disc brakes for high performance cars arrived on the scene we began to hear of "warped brake discs" on road going cars, with the same analyses and diagnoses. Typically, the discs are resurfaced to cure the problem and, equally typically, after a relatively short time the roughness or vibration comes back. Brake roughness has caused a significant number of cars to be bought back by their manufacturers under the "lemon laws". This has been going on for decades now - and, like most things that we have cast in stone, the diagnoses are wrong.

With one qualifier, presuming that the hub and wheel flange are flat and in good condition and that the wheel bolts or hat mounting hardware is in good condition, installed correctly and tightened uniformly and in the correct order to the recommended torque specification,

Here are more common problems found with rotors
cracked discs, (FIGURE 1)

discs that had turned into shallow cones at operating temperature because they were mounted rigidly to their attachment bells or top hats, (FIGURE 2)

a few where the friction surface had collapsed in the area between straight radial interior vanes, (FIGURE 3)

and an untold number of discs with pad material unevenly deposited on the friction surfaces - sometimes visible and more often not. (FIGURE 4)

pic #1


Pic#2


Link to pic #3

Pic #4


Pic#5


In fact almost all cases of "warped brake disc" , whether on a racing car or a street car, eventually turns out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.
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Old 05-30-2003, 12:10 PM   #5
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THE NATURE OF BRAKING FRICTION

Friction is the mechanism that converts dynamic energy into heat. Just as there are two sorts of friction between the tire and the road surface (mechanical gripping of road surface irregularities by the elastic tire compound and transient molecular adhesion between the rubber and the road in which rubber is transferred to the road surface), so there are two very different sorts of braking friction - abrasive friction and adherent friction. Abrasive friction involves the breaking of the crystalline bonds of both the pad material and the cast iron of the disc. The breaking of these bonds generates the heat of friction. In abrasive friction, the bonds between crystals of the pad material (and, to a lesser extent, the disc material) are permanently broken. The harder material wears the softer away (hopefully the disc wears the pad). Pads that function primarily by abrasion have a high wear rate and tend to fade at high temperatures. When these pads reach their effective temperature limit, they will transfer pad material onto the disc face in a random and uneven pattern. It is this "pick up" on the disc face that both causes the thickness variation measured by the technicians and the roughness or vibration under the brakes reported by the drivers.

With adherent friction, some of the pad material diffuses across the interface between the pad and the disc and forms a very thin, uniform layer of pad material on the surface of the disc. As the friction surfaces of both disc and pad then comprise basically the same material, material can now cross the interface in both directions and the bonds break and reform. In fact, with adherent friction between pad and disc, the bonds between pad material and the deposits on the disc are transient in nature - they are continually being broken and some of them are continually reforming.

There is no such thing as pure abrasive or pure adherent friction in braking. With many contemporary pad formulas, the pad material must be abrasive enough to keep the disc surface smooth and clean. As the material can cross the interface, the layer on the disc is constantly renewed and kept uniform - again until the temperature limit of the pad has been exceeded or if the pad and the disc have not been bedded-in completely or properly. In the latter case, if a uniform layer of pad material transferred onto the disc face has not been established during bedding or break-in, spot or uncontrolled transfer of the material can occur when operating at high temperatures. The organic and semi-metallic pads of the past were more abrasive than adherent and were severely temperature limited. All of the current generation of "metallic carbon", racing pads utilize mainly adherent technology as do many of the high end street car pads and they are temperature stable over a much higher range. Unfortunately, there is no free lunch and the ultra high temperature racing pads are ineffective at the low temperatures typically experienced in street use.

Therefore - there is no such thing as an ideal "all around" brake pad. The friction material that is quiet and functions well at relatively low temperatures around town will not stop the car that is driven hard. If you attempt to drive many cars hard with the OEM pads, you will experience pad fade, friction material transfer and fluid boiling - end of discussion. The true racing pad, used under normal conditions will be noisy and will not work well at low temperatures around town.

Ideally, in order to avoid either putting up with squealing brakes that will not stop the car well around town or with pad fade on the track or coming down the mountain at speed, we should change pads before indulging in vigorous automotive exercise. No one does. The question remains, what pads should be used in high performance street cars - relatively low temperature street pads or high temperature race pads? Strangely enough, in my opinion, the answer is a high performance street pad with good low temperature characteristics. The reason is simple: If we are driving really hard and begin to run into trouble, either with pad fade or boiling fluid (or both), the condition(s) comes on gradually enough to allow us to simply modify our driving style to compensate. On the other hand, should an emergency occur when the brakes are

cold, the high temperature pad is simply not going to stop the car. As an example, during the mid 1960s, those of us at Shelby American did not drive GT 350 or GT 500 Mustangs as company cars simply because they were equipped with Raybestos M-19 racing pads and none of our wives could push on the brake pedal hard enough to stop the car in normal driving.

Regardless of pad composition, if both disc and pad are not properly broken in, material transfer between the two materials can take place in a random fashion - resulting is uneven deposits and vibration under braking. Similarly, even if the brakes are properly broken, if, when they are very hot or following a single long stop from high speed, the brakes are kept applied after the vehicle comes to a complete stop it is possible to leave a telltale deposit behind that looks like the outline of a pad. This kind of deposit is called pad imprinting and looks like the pad was inked for printing like a stamp and then set on the disc face. It is possible to see the perfect outline of the pad on the disc. FIGURE 5

It gets worse. Cast iron is an alloy of iron and silicon in solution interspersed with particles of carbon. At elevated temperatures, inclusions of carbides begin to form in the matrix. In the case of the brake disk, any uneven deposits - standing proud of the disc surface - become hotter than the surrounding metal. Every time that the leading edge of one of the deposits rotates into contact with the pad, the local temperature increases. When this local temperature reaches around 1200 or 1300 degrees F. the cast iron under the deposit begins to transform into cementite (an iron carbide in which three atoms of iron combine with one atom of carbon). Cementite is very hard, very abrasive and is a poor heat sink. If severe use continues the system will enter a self-defeating spiral - the amount and depth of the cementite increases with increasing temperature and so does the brake roughness. Drat!
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Old 05-30-2003, 12:11 PM   #6
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PREVENTION

There is only one way to prevent this sort of thing - following proper break in procedures for both pad and disc and use the correct pad for your driving style and conditions. All high performance after market discs and pads should come with both installation and break in instructions. The procedures are very similar between manufacturers. With respect to the pads, the bonding resins must be burned off relatively slowly to avoid both fade and uneven deposits. The procedure is several stops of increasing severity with a brief cooling period between them. After the last stop, the system should be allowed to cool to ambient temperature. Typically, a series of ten increasingly hard stops from 60mph to 5 mph with normal acceleration in between should get the job done for a high performance street pad. During pad or disc break-in, do not come to a complete stop, so plan where and when you do this procedure with care and concern for yourself and the safety of others. If you come to a complete stop before the break-in process is completed there is the chance for non-uniform pad material transfer or pad imprinting to take place and the results will be what the whole process is trying to avoid. Game over.

In terms of stop severity, an ABS active stop would typically be around 0.9 Gs and above, depending on the vehicle. What you want to do is stop at a rate around 0.7

to 0.9 G's. That is a deceleration rate near but below lock up or ABS intervention. You should begin to smell pads at the 5th to 7th stop and the smell should diminish before the last stop. A powdery gray area will become visible on the edge of the pad (actually the edge of the friction material in contact with the disc - not the backing plate) where the paint and resins of the pad are burning off. When the gray area on the edges of the pads are about 1/8" deep, the pad is bedded.

For a race pad, typically four 80mph to 5 and two 100mph to 5, depending on the pad, will also be necessary to raise the system temperatures during break-in to the range that the pad material was designed to operate at. Hence, the higher temperature material can establish its layer completely and uniformly on the disc surface.

Fortunately the procedure is also good for the discs and will relieve any residual thermal stresses left over from the casting process (all discs should be thermally stress relieved as one of the last manufacturing processes) and will transfer the smooth layer of pad material onto the disc. If possible, new discs should be bedded with used pads of the same compound that will be used going forward. Again, heat should be put into the system gradually - increasingly hard stops with cool off time in between. Part of the idea is to avoid prolonged contact between pad and disc. With abrasive pads (which should not be used on high performance cars) the disc can be considered bedded when the friction surfaces have attained an even blue color. With the carbon metallic type pads, bedding is complete when the friction surfaces of the disc are a consistent gray or black. In any case, the discoloration of a completely broken in disc will be complete and uniform.

Depending upon the friction compound, easy use of the brakes for an extended period may lead to the removal of the transfer layer on the discs by the abrasive action of the pads. When we are going to exercise a car that has seen easy brake use for a while, a partial re-bedding process will prevent uneven pick up.

The driver can feel a 0.0004" deposit or TV on the disc. 0.001" is annoying. More than that becomes a real pain. When deposit are present, by having isolated regions that are proud of the surface and running much hotter than their neighbors, cementite inevitably forms and the local wear characteristics change which results in ever increasing TV and roughness.

Other than proper break in, as mentioned above, never leave your foot on the brake pedal after you have used the brakes hard. This is not usually a problem on public roads simply because, under normal conditions, the brakes have time to cool before you bring the car to a stop (unless, like me, you live at the bottom of a long steep hill). In any kind of racing, including autocross and "driving days" it is crucial. Regardless of friction material, clamping the pads to a hot stationary disc will result in material transfer and discernible "brake roughness". What is worse, the pad will leave the telltale imprint or outline on the disc and your sin will be visible to all and sundry.

The obvious question now is "is there a "cure" for discs with uneven friction material deposits?" The answer is a conditional yes. If the vibration has just started, the chances are that the temperature has never reached the point where cementite begins to form. In this case, simply fitting a set of good "semi-metallic" pads and using them hard (after bedding) may well remove the deposits and restore the system to normal operation but with upgraded pads. If only a small amount of material has been transferred i.e. if the vibration is just starting, vigorous scrubbing with garnet paper may remove the deposit. As many deposits are not visible, scrub the entire friction surfaces thoroughly. Do not use regular sand paper or emery cloth as the aluminum oxide abrasive material will permeate the cast iron surface and make the condition worse. Do not bead blast or sand blast the discs for the same reason.

The only fix for extensive uneven deposits involves dismounting the discs and having them Blanchard ground - not expensive, but inconvenient at best. A newly ground disc will require the same sort of bedding in process as a new disc. The trouble with this procedure is that if the grinding does not remove all of the cementite inclusions, as the disc wears the hard cementite will stand proud of the relatively soft disc and the thermal spiral starts over again. Unfortunately, the cementite is invisible to the naked eye.

Taking time to properly bed your braking system pays big dividends but, as with most sins, a repeat of the behavior that caused the trouble will bring it right back.
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Old 08-06-2003, 08:25 AM   #7
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A majority of this info was found at the Stoptech technical information page

www.stoptech.com
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Old 05-04-2005, 01:42 PM   #8
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Here's another link with an article I found particularly helpful in making sense of how brakes work, the relationship between the various components and what actually stops the car!

http://www.ffcobra.com/FAQ/brakes3.html
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Old 05-04-2005, 01:53 PM   #9
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This is good stuff, someone should sticky it...
If only I could afford to buy new brake components and actually use this info!
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Old 05-04-2005, 02:23 PM   #10
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Quote:
Originally Posted by Luke@tirerack

1) The brakes don't stop the vehicle - the tires do. The brakes slow the rotation of the wheels and tires. This means that braking distance measured on a single stop from a highway legal speed or higher is almost totally dependent upon the stopping ability of the tires in use - which, in the case of aftermarket advertising, may or may not be the ones originally fitted to the car by the OE manufacturer.

It's amazing how many people don't comprehend this.

I know I need bigger brakes when there is enough fade to keep me from locking up the wheels.
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Old 05-04-2005, 04:02 PM   #11
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Thanks Luke!
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Old 05-10-2005, 09:38 AM   #12
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Quote:
Originally Posted by psuknak05
This is good stuff, someone should sticky it...
If only I could afford to buy new brake components and actually use this info!
It is stickied, sort of. This thread is referenced in the FAQ thread.
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Old 06-09-2006, 07:29 PM   #13
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I know I'd appreciate a similiar description of braided brake lines, considering the difference they've made on MY car...
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Old 09-06-2006, 05:22 PM   #14
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bump!
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Old 11-02-2006, 03:46 PM   #15
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That Stoptech article says that vibrations during braking are not caused by warping. Instead, it gives the reason as "friction pad material transferred unevenly to the surface of the disc". My question now becomes: What caues the friction pad material to transfer unevenly to the surface of the disc? I couldn't find the answer to that anywhere.

Another question I had regarding that article is this: Does the article imply that warping (ie misshapen rotors due to excessive heat) doesn't exist, or does it imply that it exists, but it just doesn't cause vibrations during braking.
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Old 11-02-2006, 04:49 PM   #16
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^^^I think what the article is saying that rotors do not warp, rather they develop inconsistencies in the surface of the rotor that cause the rotor to vary in friction across the surface.
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Old 11-02-2006, 04:52 PM   #17
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Quote:
Originally Posted by chuckywang View Post
That Stoptech article says that vibrations during braking are not caused by warping. Instead, it gives the reason as "friction pad material transferred unevenly to the surface of the disc". My question now becomes: What caues the friction pad material to transfer unevenly to the surface of the disc? I couldn't find the answer to that anywhere.
One way is to come in after a track session with your brakes glowing and then sit on your brakes in grid waiting for the next heat to go out

You get the jist - clamping your pads to the rotor when they are really hot is the easiest way to do it.

Quote:
Originally Posted by chuckywang View Post
Another question I had regarding that article is this: Does the article imply that warping (ie misshapen rotors due to excessive heat) doesn't exist, or does it imply that it exists, but it just doesn't cause vibrations during braking.
They are not claiming that warping doesn't exist, as they make clear with this caveat here:
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
Quote:
With one qualifier, presuming that the hub and wheel flange are flat and in good condition and that the wheel bolts or hat mounting hardware is in good condition, installed correctly and tightened uniformly and in the correct order to the recommended torque specification,
They are just saying that most of the time someone complains about warped rotor feel, it's uneven pad deposits, not actual warped rotors. You can still warp your rotors in the conditions they describe.

john
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Old 11-02-2006, 05:08 PM   #18
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Quote:
Originally Posted by ButtDyno View Post
They are not claiming that warping doesn't exist, as they make clear with this caveat here:
http://www.stoptech.com/tech_info/wp...rakedisk.shtml


They are just saying that most of the time someone complains about warped rotor feel, it's uneven pad deposits, not actual warped rotors. You can still warp your rotors in the conditions they describe.

john
and for those of you who have wondered - this is one of the top reasons why people freak out on here when someone mentions using an airgun to tighten the lugs.
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Old 11-02-2006, 07:34 PM   #19
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Quote:
Originally Posted by Turn in Concepts View Post
and for those of you who have wondered - this is one of the top reasons why people freak out on here when someone mentions using an airgun to tighten the lugs.
Of course, if you are not a complete potzer, you can do the initial tighten with the impact driver - but you are a schmuck if you don't tighten them down with a torque wrench. Most shops use the snap-type, but it's amazingly easy to over-torque something with one of those, to the tune of 5-10 foot-pounds over! By far the most accurate type of torque wrench is the "beam" kind that bends... Torque sticks are a pretty unreliable way of torquing as well, of course.
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Old 11-02-2006, 11:26 PM   #20
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Quote:
Originally Posted by chuckywang View Post
That Stoptech article says that vibrations during braking are not caused by warping. Instead, it gives the reason as "friction pad material transferred unevenly to the surface of the disc". My question now becomes: What caues the friction pad material to transfer unevenly to the surface of the disc? I couldn't find the answer to that anywhere.
.

Material transfer back and forth between the pad and rotor is always happening as you use your brakes - it's how they work and is called ADHERENT FRICTION. My analogy is you are 'painting' a thin layer of pad on the rotor using heat and pressure to do so. Take a 'brush' full of paint ( a hot brake pad) and hold it in one spot and you will get excess paint in that area so each time you run over it again you will feel that 'bump'

Another way that you can develop an UNEVEN transfer layer is if a cold pad that is in ABRASIVE mode strips off a portion of what was a uniform layer. This might occur for example if you go on track and hit the brakes really hard before they are warmed up - the pad strips off part of athe layer and you have the same issue - a 'bump' that the pads hit eash time the rotor comes around


Quote:
Originally Posted by chuckywang View Post
Another question I had regarding that article is this: Does the article imply that warping (ie misshapen rotors due to excessive heat) doesn't exist, or does it imply that it exists, but it just doesn't cause vibrations during braking.
Of course rotors CAN warp - it's just much more likely that an uneven transfer layer is the cause of judder. So if you are experiencing judder - rebedding the pads - sometimes more than once - is the first and easiest possible solution. I have instructed people to do this numerous times with success.

One key is to look at the specs for rotors.

Disc thickeness variation specifications are measured in the ten thousandths of an inch....runout is measured in thousandths. An uneven transfer layer is more felt in the pedal - the pads are 'going in and out' pushing fluid back up the line to your foot.

Warping might be felt more in the steering wheel as you move the entire caliper 'in and out' shaking the wheel.

And you could very well have both scenarios of course.
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Old 11-03-2006, 11:16 AM   #21
hyperdrink
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Quote:
Originally Posted by cellobro View Post
I know I'd appreciate a similiar description of braided brake lines, considering the difference they've made on MY car...
Just because there ought to be something about them here, I'll write something :P

The purpose of steel braided brake lines is twofold. The less-important reason is that the steel braid protects the brake line from abrasion damage, but this is usually not a problem (except when your car is seriously damaged, of course.) More importantly, the braided metal jacket is there to prevent undue expansion of the brake lines.

Nearly all brake systems utilize a flexible line (usually called a "flex line") to deliver brake fluid pressure to the brake caliper, as the caliper is mounted at the wheel, which itself is moving on the suspension. This flexible line is made out of rubber and during hard braking, it can actually expand. You don't necessarily think of this while you're pressing the pedal, but Boyle's law says that the pressure throughout a closed system will be the same no matter where you measure it; at the master cylinder (M/C), the brake caliper, or in the line. This can result in a "mushy" pedal feel that can be quite disorienting during performance (or even regular) driving.

The solution is to run a reinforced line. While you can get reinforced rubber hoses, which use belting to avoid expansion in much the same way your tires or your radiator hose does, they are inferior to the type that is wrapped with a steel braid. You should be aware that even this type of line has some expansion, but it is dramatically less than the other type. As a bonus, this will prevent you from bursting your brake lines in almost any situation.

While there are really no drawbacks to having braided lines beyond having to pay for them, you do need to check them periodically for damage. If the steel braid is somehow severed, the ends of the strands of wire from which it is woven can potentially cut through the hose. If your braid is damaged at all, you should replace the line. Be careful while checking the lines for damage; if you run your hand over a damaged section you can easily end up with bits of stainless steel wire stuck in your skin, which is not a fun experience - trust me. They also make the pedal feel much firmer, which can be worrying for someone used to driving stock vehicles if they don't know it's supposed to feel that way.
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Old 11-03-2006, 01:38 PM   #22
bigsky92x
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Luke,

Thanks for a well written thread. It answered a lot questions I had about brakes and braking.
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Old 11-03-2006, 02:51 PM   #23
waktasz
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Where's the 2006/2007 WRX brakes?!
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Old 07-17-2009, 06:05 AM   #24
subi400
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Hi, I have a 1996 subaru impreza outback and I bought a pair of cross drilled rotors for the front of my car. Well, they worked fine at first as i did do the break in part, then I started to get some chatter no only from the brake pedal but also from the steering wheel. So I am wanting to upgrade the brake system for my car with new rotors, calipers, pads and stainless steal brake lines. The wheels on there right now are 15's.

So do you think it could be deposits on the rotor surface or warped rotors or both? Let me know as I need to take care of this as soon as possible
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Old 07-20-2009, 01:38 PM   #25
subi400
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Bumpin it to the top
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