Originally Posted by KJSmitty

Depending on the severity of rotor "warpage",,, you may/will feel a pulsating sensation in the brake pedal, a shimmy-back and forth motion in the steering wheel, and usually a "surging" motion or feel in the entire vehicle. Overall this is most noticable at moderate to heavy braking coming from say highway speeds. I tend to also notice it when I am just creeping up behind someone in traffic at slow speeds (less than 5mph) while slightly riding the brake. The car surges like you are slowly "pumping" the brakes.

Originally Posted by apwalsh

3Putt: All that boiling water and heated metal is true, but isn't the heat generated by the brakes caused by friction? And by reducing the surface area on which heat will be generated by friction would allow the rotors to remain cooler longer.

Originally Posted by Sherlock

I too have had the issues with Honda/Acura and warping brakes. I had my 98 Accord turned twice in the first 2,000 miles due to this. Honda puts the "just barely acceptable" braking power in their standard cars (brembo excluded). Hence why they have nearly the worst 60-0 and 70-0 stopping times. My 04 TL was turned in the first 1,000 miles.

Anytime you have an "incident" and have to use the ABS, you'll most likely warp them, mine have vibrated anytime I've had to jam on the brakes for an idiot Atlanta driver and the ABS kicks in. Figure at that point you're at maximum pressure and usage, minus only the pulses from the computer.

Along with the letting off the brakes at redlights, I read on this forum years ago about stopping a car length or more from the next car, and just creeping towards them during the light so that the rotor can get out from under the pads and cool a little more evenly.
Another one I read on here is not to go home and wash the car within say, what, 15-30 minutes. Splash them with the hose and you cool them unevenly and too quickly.

I've had Honda cover the rotor turns under warranty, I think they know that they are subject to it and are just used to it.

And you think that it would be in their "best interest" to torque them correctly so that they don't have to come back in ?? Honda reimburses them for labor, and the shop still makes their money, why wouldn't they ruin your cars on purpose (or just hap-hazardly) so that they get more work and labor ? If they argue 90% of the people that warpage isn't covered, and 50% balk and they cover that many, they've still made money on the other 50%.

I love it when the salesmen come off with telling people that the service shop in their dealership isn't the same "company" and they can't speak for the work "over there". A customer thinks that two buildings, adjoined, with the same banner on both, IS the same company and would expect and respect the same quality (or maybe not) service from both.

Honda puts on crap for stock brakes, most of us have just come to expect it over the years. Especially now that they're up to 270hp 3500lb cars, and have 70--0 braking in the 180-210 foot range ?? gimme a brake (on purpose)

Originally Posted by 3PUTT

just to quote another member's (dcarlinf1) comments:

Separating fact from fiction



I and many of my autocrossing and road racing friends have been trying to separate the marketing hype from the product and explain the existence of Eradispeeds or any cross drilled and/or slotted brake rotors. Mostly, there seems to be a misunderstanding of the reasons for drilling holes in a perfectly good rotor. Cross drilled rotors have somehow become the "magical cure" for your brakes. Many would like you to believe that they will help you stop faster, they will wear better, stay cooler, and they can magically avoid warping. Unfortunately all of these things are false. But, since the guys who make these products spend more on advertising than I do (ok, I don't), it is easy to fall into that trap.



Broken down to the most basic physics (don't worry, no serious math involved here). You will begin to see the reasons they can't do the things they are touted to do.



The "basic" lesson:

Ok. If I am trying to boil a pot of water with 2 gallons of water in it. It will take a lot of heat to get all of that water up to boiling temperature. Right? Now, if I remove 1/2 the water and with it, 1/2 the mass used to absorb heat, it will now be easier to get that water to boil since there is less mass to absorb heat. Make sense?

Ok, If I take a 3 lb chunk of metal and a 6 lb chunk of metal and set them both over a small torch, which one do you think will heat up first? The lighter mass will see a more rapid temperature rise (it will get hotter, quicker). Correct?

Now, if I take a brake rotor that weighs 20 lbs and begin making "panic stops" with it, it's temperature will increase. Easy enough.

If I now take the same rotor, drill holes in it reducing its weight to 17 lbs and make the same "panic stops", would it not make sense (from the above examples) that the lighter rotor will end that stop with a higher temperature? Less mass to absorb heat will cause a more rapid temperature rise.

Many will say "cross drilled rotors cool better". Hmmm. If you really look at it, how much air do you think can blow through those little holes? Add the fact that they are spinning at a reasonably high speed and the cooling argument becomes even less believable. In fact, the holes could, in theory, disrupt the natural draw of air from the center of the rotor to the outside edge. That is the flow that actually cools the rotors.

The reason:

Rotors were originally drilled to eliminate something known as "green fade". The best way to explain "Green fade" is to relate it to an air hockey table. The puck is suspended on a cushion of air that prevents it from touching the table, this reduces the friction between the puck and the table.

A long time ago, pads were made with the best resins we had available. Many of those resins would produce gas as they cured. When a pad was used the first few times, the heat would "cure" the resin which would cause it to produce vapors. This was known as "out gassing". The vapors would build up between the pad and the rotor and lift or "force" the pad away from the rotor (like the puck in air hockey). This caused the brakes to be very ineffective, even though they were not yet at the maximum rated operating temperature. The holes were drilled to allow that gas a place to escape. So, it is correct to say that rotors were cross drilled to eliminate fade, but not for the reasons you would think. The good news is that today's resins no longer suffer from these problem and the modern race pads are so good that this is really no longer an issue. So, by cross drilling rotors, you will only manage to shorten the lifespan of that rotor (it now has less surface area to wear against the brake pad and will wear more quickly as well as a reduction in weight that will cause the brakes to operate at a higher temperature).

Another problem with cross drilled rotors is the potential for cracking around the holes. The holes become a stress point in the cast iron that can more readily allow cracks to form in the rotor surface. This requires that you pay close attention to the rotor surface for signs of cracking. Some small cracks, known as "surface checking" are acceptable, but anything that resembles a crack would be a reason to replace that rotor. When looking at slotted rotors keep in mind that the slots should not be milled off of the edge of the rotor. This is a great place for cracks to form, and they will. The slot should be ball milled in the rotor face and originate and terminate on the surface of the rotor without exiting the rotors edge. The goal is to eliminate sharp edges that cause stress risers on the rotor surface. This will reduce the possibility of cracking. If you see slotted rotors with slots that are milled off the edge of the rotor, shop for another brand. Slots that are not cut through the edge of the rotor are a good sign that the manufacturer of that rotor knows what they are doing. This is a good indicator of parts made by a brake company and not a machine shop that happens to drill and slot rotors.

Many years ago, when I ordered my first brake kit from Baer Racing, they told me that drilled rotors would typically last 20% less than an equivalent solid rotor. This was why they always recommended solid rotors for extreme use. Baer has changed their stance on this since discovering there was a large amount of money to be made selling "Eradispeeds" (they are very pretty brake rotors). This change in their marketing strategy has caused me to feel that they have gone from "supporting the racing community" to "making maximum money". And, I guess I can't blame them.....

If you are truly looking for upgraded braking performance for your car. I suggest, as a first upgrade, that you leave the stock size rotors and upgrade the pads. Try a set of Hawk HPS pads or something from Larry at Carbotech Engineering (www.carbotecheng.com). You'll think you put "big brakes" on all 4 corners (compared to stock).

If you must go bigger, look at the G-stop kit from LG Motorsports. It will let you use a C5 Corvette rotor. Bang for the buck, the LG kit is an excellent choice. There are larger kits and they increase in both cost and braking ability. Only your needs and your budget are the limit.


Tires:

I'd also like to take a moment to address the impact that tires have on braking performance.

While it is true that the tires have the "last word" with the pavement when it comes to how the car accelerates, turns, and brakes. There are a few things that tires can and can't do. While it is true that a car on wide, sticky tires should and will out brake the same car on thin, non-grippy tires (all other things being equal). And, while tires are extremely important. They become less important on the 5th or 8th stop or the 3rd lap of a road course. By then the brakes (depending on rotor size, cooling, pads, etc) may be so hot that they can't lock up the skinny little tires, much less the wide, grippy ones. This is where upgrading the brakes pays dividends. This is not meant to minimize the tires role in braking performance. Simply, you must remember to weigh the tires limits against the brake systems limits. You are working with a "package" and changes in one can impact the other. So, while tires will be the limit on the first few stops, they will play a less important role as the brake system temperatures increase. Remember, just because you can lock up the tires on the first stop does not mean that you can't benefit from brake system upgrades.

Originally Posted by 3PUTT

If you are truly looking for upgraded braking performance for your car. I suggest, as a first upgrade, that you leave the stock size rotors and upgrade the pads. Try a set of Hawk HPS pads or something from Larry at Carbotech Engineering (www.carbotecheng.com). You'll think you put "big brakes" on all 4 corners (compared to stock).

If you must go bigger, look at the G-stop kit from LG Motorsports. It will let you use a C5 Corvette rotor. Bang for the buck, the LG kit is an excellent choice. There are larger kits and they increase in both cost and braking ability. Only your needs and your budget are the limit.

Originally Posted by ndnboy

I believe your rotors become warped or don't spin in a true straight fashion from heat, they become warped but sometimes its not very noticable to the eye, so when the calipers apply the pad on the rotors to stop the cars the warp or the unevenness of it cause the front brakes to "shimmy" or vibrate, my old honda had gotten so bad it was almost violant, then you get the rotors "turned" or "cut" they take away a small fraction of the braking surface from the rotor hopefully revealing a once again true spinning rotor or non warped. I think thats the best way I can describe it but I 'm not exactly a mechanically inclined kinda guy!

Originally Posted by 3PUTT

just to quote another member's (dcarlinf1) comments:


The "basic" lesson:

Ok. If I am trying to boil a pot of water with 2 gallons of water in it. It will take a lot of heat to get all of that water up to boiling temperature. Right? Now, if I remove 1/2 the water and with it, 1/2 the mass used to absorb heat, it will now be easier to get that water to boil since there is less mass to absorb heat. Make sense?

Ok, If I take a 3 lb chunk of metal and a 6 lb chunk of metal and set them both over a small torch, which one do you think will heat up first? The lighter mass will see a more rapid temperature rise (it will get hotter, quicker). Correct?

Now, if I take a brake rotor that weighs 20 lbs and begin making "panic stops" with it, it's temperature will increase. Easy enough.

If I now take the same rotor, drill holes in it reducing its weight to 17 lbs and make the same "panic stops", would it not make sense (from the above examples) that the lighter rotor will end that stop with a higher temperature? Less mass to absorb heat will cause a more rapid temperature rise.

Many will say "cross drilled rotors cool better". Hmmm. If you really look at it, how much air do you think can blow through those little holes? Add the fact that they are spinning at a reasonably high speed and the cooling argument becomes even less believable. In fact, the holes could, in theory, disrupt the natural draw of air from the center of the rotor to the outside edge. That is the flow that actually cools the rotors.