Anyone have any experience with Brembo cross-drilled or slotted brake rotors for a tC? Tirerack. com claims to have rotors for tC but Im wondering if you can just buy the rotors and they will work with stock brakes and pads. Tirerack implies that you can but Im not sure I buy it. Thoughts?

 

Obviously you want this for looks, in which case I'd say go all out and get the pads/calipers too. Just get a "big brake kit". As far as performance, it's not necessary and in actuality cross-drilled rotors vs. non-drilled rotors of the same diameter will offer less braking power than the latter.

 

First ask yourself why you want to upgrade your brake rotors. If your answer is "to stop faster"...look elsewhere

 

Actually you will stop quicker because drilled and/or slotted rotors reduce brake fade and help to dissipate the gases built up from friction between the pads and rotors. But there are a few draw backs to crossdrilled rotors 1) if you warp em you're done they cannot be turned 2) if they get too hot they may crack( this is a common problem but not usually on street cars). The brembo crossdrilled rotors are good rotors and will work with the stock pads and bolt right up. But you're talking about $459 + shipping when stop tech has slotted rotors, pads,SS brake lines, & Motul brake fluid for like $549 which one seems like a better deal. Personally if i were in your shoes i'd either do like Rivulent said and big brake it or get the stop techs.

 

Nope, sorry...brake fade is not the same as stopping faster.

If you can stop hard enough to activate your ABS, then installing larger rotors will not help you stop faster. Remember, the thing touching the ground are your tires. If you are exceeding the limit of adhesion of your tires, then you are only going to stop as fast as your tires can take you. Changing tire compound, increasing your contact patch, or decreasing your overall weight will increase your limit of adhesion and make you stop faster.

Unless you are tracking your car, you will not stop the car hard enough and in fast enough succession to experience brake fade. These are not cars from ancient history where brake fade is a concern after coming from one semi hard stop off the highway. If you are planning to track your car, then you probably started on the wrong platform.

Cross drill/slotted brakes will not help you dissipate heat faster either.

Brakes rotors on your car have to do two things. First, it must disperse heat from the friction created from the caliper clamping onto them. Second, it must dissipate that heat. The mass of the rotor assists with heat dispersal. It takes much more energy to heat a large item than it does to heat a small item. As brake force is applied and things heat up, the heat is able to be distributed throughout that entire mass. If you remove some of that material, which is the case when rotors are cross-drilled, you not only have removed material that assists with dispersal (this may actually result in increased temp) but you've also reduced your swept area (cross-drilled rotors typically have ~85% or so of the surface area that a solid/blank rotor will have – 15% less). So, decreased mass results in a lesser ability to distribute heat energy thoughout the rotor, thus making it less "efficient" at dissipating heat, which in turn results in increased rotor/pad temperatures and reduced braking performance. In addition, there is an additional point of heat stress, which of course means it’s a risk to structural integrity. If you look at used cross-drilled rotors from a race (this is becoming rare...not to mention they may use different materials) you’ll notice heat cracks originating from the holes (you’ll also notice they throw these away after just about every race...how practical is that?).

Vented rotors (pretty much all rotors today are vented) were designed to assist with the heat dissipation. They assist in the removal of heat from the metal and the pad while maintaining the surface area. Cross-drilled rotors have holes drilled into each face of the disc, either right through, or into the vents (in most cases manufacturers are just drilling into a blank). This does nothing to increase surface area for cooling. Think of it like this, which does a better job of handling heat, a cast-iron kettle or a pizza pan with holes in it? The original idea behind cross-drilled rotors was to allow gas build up from the pads somewhere to go in order to prevent brake fade (a much larger issues several decades ago), but this comes at the cost of surface area for the pads and thus less braking force. If manufacturers claims are true, then given the modern compounds used in brake pads, there is no need to cross drill rotors.

As for the swept area, the more friction that can be generated between the rotors surface and the brake pad, and greater energy transfer (stopping power) can be obtained. A smooth surface will help insure that more of the pad surface area is in contact with the rotor.

The only way a cross-drilled rotor will make a difference in overall braking is if you increase swept area and/or increase the mass to make up for the material that was removed. Again, you need to account for heat dissipation and maintain braking surface area.

Sorry to get so technical

 

you have to be consistently braking HARD (like at a track)to build enough heat to make slotted/drilled rotors worthwhile.

big brake kits are not that beneficial if you dont upgrade your master cylinder. you need more fluid and pressure to push more/larger caliper pistons (240sx owners who upgrade to 300zx twin turbo brakes upgrade master cylinders to get the full benefit of the brakes). with stock brake pressure, youre not pushing those calipers down any faster, but you do get a greater contact area, which reduces the amount of heat created (but only useful if youre braking hard consistently, like slotted/drilled rotors). another thing to consider is the price to replace pads and rotors on big brake kits. youre not gonna find these easily or cheaply at your neighborood pep boys.

all this stuff about cross drilled/slotted rotors or big brake kits is marketing to make people think they're braking faster.

for a daily driven street car that see minor track time, invest in a set of really good pads. maybe brake lines too. and thats its. if you want to autocross, buy special pads for the event, and swap back to stock pads afterwards. any real racer has a dedicated set of wheels/tires and pads just for event days. for every car i've owned, i used brembo blank rotors.

 

I'm not about to start an arguement over this but you are wrong on about 90% of the things you said in your post.

 

Then please explain to me in detail what I said that is incorrect.

 

Ok the parts where you said crossdrilled rotors don't disapate heat better and they. Where you said they won't help you stop faster you were wrong because they will. I have a car with abs and crossdrilled and it stops quicker or in a shorter distance i should say. ABS is always active and when you hit the brakes soft or hard it is active only when you press the brakes and let off then re-apply will it not be active.

The more the pads and rotros come in contact with one another the more friction there is meaning more heat. The more heat you have the brake fade you have. By drilling the rotor you do cut down on the surface area thus reducing friction in turn reducing heat.


in short.

 

Take a look at this article

http://www.teamscr.com/rotors.html

Do you know what brake fade is? Brake fade occurs for two primary reasons. The first and most common one is your brake fluid boiling over and turning into a gas. The gas prevents your brake fluid from effectively squeezing your caliper. The other reason you experience brake fade is when you exceed the effective operating temperature of the brake pad. Brake pads either stop really well at cold temperatures, but performance dwindles when they are heated up, or they stop really crummy at cold temperatures, but stops the car phenomenally when they are heated up. I digress...

Getting back to what you said before...you do not want to decrease friction. Think about what is slowing your car down...friction. Decreasing friction makes your car slow down not as fast! You need friction, but its your brake component's job to manage the heat put out by that friction.

 

So you're telling me that when brakes are hot they stop better? IF This is true that why do you try to keep the brakers cooler?? As far as your article thats someones opinion not a fact and they don't talk about them using crossdrilled rotor. All they talked about was using a non drilled rotor and a cryo rotor. I'm telling you I havea car with drilled rotors and the car stops quicker.

Oh and if a big brake kit won't stop a vehicle better or quicker why do they have to upgrade the brakes on SUV's with 24+ inch wheels? To stop a lager rotating mass thats why. Like i said eariler i'm not trying to start an arguement with you or anyone. Just don't believe everything you read on the internet

 

Okay, lets recap...when you slam on your brakes, your car slows down. Your car will only slow down as fast as your tires can manage to grab the pavement. Due to the laws of physics, the energy from your forward momentum has to go somewhere...in this case, it is converted to heat. Your brakes do that. Now, heat will be present no matter what. Assuming that you are braking at 100% of your car's ability, the amount of heat you generate will not change unless you increase the clamping force of your brake pads onto your rotors, if you do a full-on brakes for a longer period of time, or you brake secessively.

You want to keep your brakes cooler because like I said before, your brakes are suppose to manage that heat through dissipition and dispersion, but that amount of heat is not going to change. What you are saying is you want the caliper to decrease the amount of friction caused when clamping onto the rotor, correct? This will make the car not stop as fast! Its like you want to push the brake at 90% capacity vs 100% capacity.

Correct, it is someone's opinion, but I thought he would articulate it better than I could. He is also a Stoptech and Hoosier sponsored club racer and has ran in numerous SCCA national events. Maybe your car stops faster because of the cross drilled rotor...but take a look at this:

(test results according to R&T):
'00 Porsche Boxster S - cross-drilled standard
F: 12.5 (diameter) x 1.1 (thickness)
R: 11.8 X 1.0
Braking distance
From 60 to 0- 125 ft.
From 80 to 0 - 219 ft.

'99 Porsche Boxster - solid standard
F: 11.74
R: 11.5
Braking distance
From 60 - 121
From 80 - 214

Although in this example, the Boxster s weighs about 100 lbs more, the S also has wider, stickier tires than the non-s.

Yes, but we are talking about braking performance here between cross drilled vs plain face rotors.

I don't think this is an argument...moreso a discussion for the sake for improving everyone's knowledge.

 

dude i give up!! You believe whtever you want and i'll still be right! Peace!!

 

You said i was wrong in my post...I'm just trying to understand where I went wrong? I have been to driving school, a handful of autox's, and a member of bira.org. Maybe all that I learned there is wrong too

All you really said is your car stops faster with cross drilled rotors without any basis as for how or why. Do you track your car?

 

** jboogz** <<<<<<throws in the towel !! I made my point and backed it up with actually owning and using the rotors we're talking about. You made a few statements based on an article you read. Then you come back talking about driving school and autocross. I don't believe you and thats all i'm gonna say!!

 

I can go scan in my skip barber certificate...but then you'll probably think I p-chopped it. Nevermind...im done with this too. You can believe what you want.

 

SCORE!! one for me buddy!!!

 

Glad to see my innocent query generated such a firery back and forth. As usual the internet leaves me completely baffled with compelling arguements on both sides of the issue. Obviously performance of cross-drilled rotors is a contentious subject but can you both agree that cross-drilled rotors at least "look" cool? Sorry to be so shallow but I anxiously await your takes and no fighting.
peace

 

Not at all.
Your argument involved "I am correct..." and that's about it.

 

erm mods...lock this thread please. take it somewhere else guys

-taek