OK..Here goes a loaded question... The "lifetime" rotors I installed last year are starting to exhibit signs of warping. I'm considering asking the manufacturer about their warranty. All in all, considering how I drive, these are some of the best rotors I've ever used. So, I am considering going back to conventional rotors. The "whirring fan" sound from the drilled and slotted rotors gets a little old at times. My dilemma is do I go to ceramic pads or stay with the performance semi's that I have?
Heat is a concern, not dust. The pads I got don't give off brake dust like the typical semi pads do. My wheels stay pretty darn clean. So, back to the heat issue. I know that heat from heavy braking is the leading cause of rotor warp. Also, the generation of heat is the byproduct of solid braking..IE the energy of motion turned into heat energy through the friction material to stop the car. My experience with ceramics in the past has not been the best. They definitely didn't warp rotors, but the brake performance was pretty lack. They don't generate heat like semi or full metallic pads do. So, you would think I had made up my mind..
The thing is the S has much better calipers than the "generic" cars I've had in the past. So, considering the dual piston calipers will I get sufficient performance from ceramic pads? Now, I know there are some people that swear by inexpensive ceramics. That reference, while appreciated, doesn't apply here. My driving style is WAY more aggressive than most, hence the reason I noticed the lack of bite on ceramics installed on my Accord. I just brake real hard and late into turns and such. Again, this is my style, and saying "drive differently" is a mute point and doesn't really answer the question. So, any other "enthusiastic" drivers out there use ceramics with any luck????

 

Jeff,

I'm running ceramics on stock solid rotors... They work well, better than the stock pads, they squeak a bit especially at low speed / creeping on the brakes type stuff - pulling into a garage or parking space.

It's all a tossup here. Ceramics are harder pads, worse on rotors, and slower to warm up. But much better bite when up to temp, and much less brake fade. Also much quicker to scrub off heat. Ceramics most definitely can and DO warp rotors. They also wear rotors at a faster rate. Especially when driven hard.

Think about it for a second, The hydraulic pressure remains the same, but now you have a harder surface being pressed into the metal disc. The rotor takes much more of the wear than the pad does.

The key to ceramics is if you're an a aggressive driver, you need to get them warmed up and keep them warm. You need to make an effort to stop a bit hard to get some heat in the brakes. Almost as if you're trying to warm up tires.

Now on the street, semi metalics are probably a better overall choice as far as daily driving braking performance. I.e. panic stops with the brakes cold. But they make a mess. It's not the pad that warps rotors.. It's the driving style. Any pad will warp a rotor eventually.

I am not a fan of drilled / slotted rotors, - there is NO need for them on the street other than for show. First they are much more prone to cracking / warping. Second, they basically act as if you're running a cheese grater over the pad. Solid vented discs work just fine. The whole drilled / slotted rotor thing is a byproduct of racing technology, but are designed with a pad so hard that until its warmed up would barely stop.

George

 

Just a technical point- the amount of heat generated has nothing to do with the type of pad or rotor being used, it's directly related to how quickly the car is being stopped.

I've got OEM pads on the front and Raybestos ceramics on the back of mine and experience no problem with spirited driving. I'll be switching to ceramics in the front when the time comes.

 

No, it absolutely has to do with the composition of the materials being used. Yes the quicker the stop, the more friction being generated, and the quicker kinetic energy is being converted to friction. BUT how much gets converted into ground material (pad and rotor), and how much is retained in the materials as heat, is completely dependent on the combination of materials, their thermodynamic properties, and their yield rates.

George

 

Which is true if the temperature is being measured out to the seventh decimal place. The volume of pad material loss from one type to another on a single stop is negligible.

 

We're not talking about pad material loss, we're talking about heat retention. And yes the volume of pad material loss does vary greatly between pads. Run race compound pads, and beat on them. You'll kill a set in a weekend. But it will stop harder (once they are warm).. Then run semi-metallics, and make the same stops, and the pad will look brand new at the end of the weekend.

Soft pads stop great, make a mess, and last 10k miles... Everything is a compromise. Hard pads stop meh, but last longer, and take a set of rotors with them when they go... And yes, the amount of heat generated varies greatly too.

Energy is morphed into two forms when braking a) material loss, and b) heat. The more a pad gives up material, the less will be stored as heat. The amount of overall instantaneous energy also varies (and heat) greatly depending on the pad and the material's coefficient of friction. From 60mph to zero requires a fixed amount of energy. How long it takes to stop determines how much energy the brakes are dissipating at any instantaneous moment.

George

 

The OP does not mention heat retention, he mentions heat generation. That is the point I was clarifying.

 

Your point is still completely flawed. The amount of heat generated (generated is a flawed term, really its energy converted to heat) is not a function of how quickly the car stops independent of pad / rotor combination.

The amount of energy the brakes dissipate at any given moment is. How much of that energy is shed as pad / rotor material loss, and how much is converted to heat varies greatly based on the pad / rotor combo.

George

 

We're now going in circles. I guess we'll agree to disagree.

 

So now I'm scratching my head. I'm sorry if I didn't get my point across well enough. I meant to describe what George is talking about. The conversion of energy to heat and how the different materials handle them. Now, my most recent experience with ceramics was on the Accord. I did not like how they bit in a panic stop...Yes, if I was out "playing" they would heat up and bite nice plus they never faded. Also, I never warped a rotor with them... But, many times I would be doing highway driving and have a situation that called on some serious sudden braking...Lets just say that the Accord would cause some serious "butt pucker". Now fast forward to the S...Same situation on the highway and it feels like my face is gonna peel off...As far as the drilled rotors go..Mine are perfect as far as cracks go..They have really held up well. They show minimal wear and the only time I get any vibration is under moderate to heavy breaking, and then it is very slight. It may not be the rotors at all...I've done my "light brake while driving" test at speeds of 40, 60, and 80 and only at the 80mph mark can I get just a hint of vibration. So, I think they did a good job of dissipating the heat generated from heavy braking real well..And, the Centric brand pads work real good...I'm just afraid that I'll shake my fillings loose real soon if I switch back to solid rotors and use the same low dust semi-metallic pads I am using now...And when I say "low dust" I mean it...Remember the pictures of the new center caps? Those wheels have not been washed, other than the pressure washer car wash, since last fall!

 

Keep your current rotors and semi-metallic pads. For braking under the majority of road conditions, I think you'll be happier overall. If your lifetime rotors are indeed warping, then call the vendor to the front of the class on the warranty and get them replaced at no cost to you....

 

So you're more interested in cold vs. hot performance, and also pedal effort/feel for a given stopping rate? Can't offer too much to help there.

My best 'stopping' car is an old Corvette with stock rotors and standard GM organic pads. Next is the S type with the mixed pads as noted above, I note no difference in cold vs. hot performance. Worst car is an old Infiniti with brand X semi-metallic pads. Won't stop worth a **** under any condition.The GFs Honda with OEM pads stops just like a Honda. Boring.

The conclusions I could draw from the above would just muddy the waters even more.

I agree with George on the slotted/drilled rotors, waste of money.

 

I basically agree that your better off with semi-metallics for aggresive street driving under most real-world situations. I would stick with solid rotors.. But that's just me. You should run a runout dial on the rotor and see if it is indeed the rotor warped that's causing your vibration. How bad is it? and can you feel it in the wheel and the pedal or just the pedal? My wheels were caked black with brake dust (which I still can't get all off) when I got the car, so I jumped into ceramics to try to avoid dust. I hate the low speed creeping squeals.
I'm going to run them till they wear, and then I'm going to try to find a real low dust semi like you have.

Are you just looking to get rid of the vibrations, or is it time for pads as well? The biggest thing that I have heard that warps rotors is aggressive driving when wet out. Supposedly the heat /cooling cycle when ambient temp water hits the brakes tends to cause warping.

I think the solid rotor is the way to go to get the most overall bite out of the pad, the rotor least likely to warp etc..

Oh btw - I picked up a set of staggered 18" 06 STR wheels... Hopefully there will be no drama with them.

George

 

See, one of the reasons I'm thinking about going back is the loud fan like noise they make at higher speed braking... Like an exit ramp..That I do multiple times a day, every day.. So, I'm looking for feedback from other people that might also be hard on brakes....If it looks like the only way I'm going to get the performance I'm after is to stay with what I have, I will. I just know I'm not the only one that brakes hard. I will definitely put up with the "industrial fan" if that is the safest way to go..

Mikey: So, how long have you been running the OEM pads on the front? How hard are you on the brakes? Last but not least, and the reason for posting, why are you going to switch to ceramics?

 

I Still think the best braking with semi-metallics is going to be on a solid rotor. Plus u get rid of your whirring noise as the pad skips over the slots in the rotor... Almost like a tiny version of putting a playing card in your bicycle spokes when you were a kid.

You can also get better braking by compromising pad life and making a mess... Think EBC green pads here Or Mintex Red's.

Hawk also make HPS's for the S.

OEM Jag pads are TRW. Not the best, not the worst.

George

 

I am looking to get rid of the vibration. That is new. I haven't checked for runout, ect. I only feel it under braking through both the pedal and the steering wheel...Also, some of the steering wheel vibration is the tires, I'm certain. It doesn't vibrate through the wheel just driving so I'm not ready to throw out the tires, yet. None of this is a major issue, yet. I just like to replace stuff as I feel it going instead of being in the "I gotta do it this weekend" situation. I've heard that wet cycles and even "full stop/sit" cycles can cause the rotor to warp. Full stop then sitting with the brakes on can cause the rotor to dissipate heat differently where the pad is resting on the rotor. So, you think the same brand semi I was using with solid rotors?

BTW: I can get you the Centric part numbers if you want...Those semi pads have been real clean for me! And, Congrats on the new wheels..What type are they? I know there two different wheels that cam on the STR. Are the ones you got the Vulcan wheels?

 

I am looking to get rid of the vibration. That is new. I haven't checked for runout, ect. I only feel it under braking through both the pedal and the steering wheel...Also, some of the steering wheel vibration is the tires, I'm certain. It doesn't vibrate through the wheel just driving so I'm not ready to throw out the tires, yet. None of this is a major issue, yet. I just like to replace stuff as I feel it going instead of being in the "I gotta do it this weekend" situation. I've heard that wet cycles and even "full stop/sit" cycles can cause the rotor to warp. Full stop then sitting with the brakes on can cause the rotor to dissipate heat differently where the pad is resting on the rotor. So, you think the same brand semi I was using with solid rotors?

BTW: I can get you the Centric part numbers if you want...Those semi pads have been real clean for me! And, Congrats on the new wheels..What type are they? I know there two different wheels that came on the STR. Are the ones you got the Vulcan wheels?

 

If your happy with the performance of the pads, and the dusting - then why not...
Those Centric pads are a decent value - they are the posi-quiet series right? I would do a solid rotor, if for nothing else, less noise.. I don't think there is a performance benefit to them.

As far as the wheels, I don't know the name but here's a pic of an STR with them.

18x8 front, 18x9.5 rear.

George

 

I've had great experience with semi-metallic pads and OEM (solid) rotors... As noted above, a little squeaking at slower speeds, but great braking with minimal dust on hot or cold stops.

 

Those STR wheels look like Vulcans