Im looking into new rotors for all four, i heard that having slotted and drilled rotors are not good cause they have less surface area to grab on to and less braking?? is that true?? should i go for slotted and drilled or just the normal rotors? r1 premiums have good price they good? stillen rotors good?

 

No you get better heat dispersion and the slots clean the pad and help the pads brake better. Ive heard of r1 rotors rusting right away. I bought the stoptech slotted rotors, stainless steel brake lines and Axxiss pads all in a package. I researched each of the products and I could not be happier, best pads Ive ever driven on. They dust a tiny more than oem brembos but they are amazing.

 

For normal everyday driving, doesn't really make a difference either way. I've had slotted/x-drilled for over a year now and haven't had any problems....

 

The temperature rise is purely a function of rotor weight and the thermal conductivity of the cast iron grade selected.

In the 3 seconds a normal panic stop takes the air flow [speed] is not sufficient to cool the rotor very much.

Normally a single 60mph panic stop adds ~~140 F average to the starting rotor temperature. Typical fronts have 63% and rear 37% of total mass due to the weight shift in a panic stop.

This patent has an explanation of how vanes and vents cool rotors and how to calculate what improvements are possible:
http://www.patentstorm.us/patents/67...scription.html

Please read from start to finish and try some of equations:
http://www.teamscr.com/grmbrakes.htm

 

Yeah, that's what I do with auditors-flood them with paperwork, so they would get lost and confused and too embarassed to admit that they understand nothing and eventually get off my back

 

what do u mean they rust right away? after washing the car or just normal driving? is getting rust faster bad for braking? are the pads gonna wear out quicker?

 

You need search on the sight for R1 rotors theres a couple threads I know of. The rust in not in the area where the pad touches the rotor, they will never be rusty as long as you are driving regularly. The rest of the rotor has been known to get rusty quickly, those rotors are cheap rotors from China I believe. You can get generic rotors like that pretty easily, but quality may suffer, thus your braking will too.

 

Slotted rotors do not disperse heat and do not clean the pad. Drilled rotors allow for better disc cooling, but with drilled rotors you run a greater risk of the rotors cracking. Slotted rotors heat up the pads so that your breaks can grip the rotor better.

My rec. is you give Scott a call and he'll recommend what you should go with keeping in mind your goals and your price range. He races these cars so he knows what's best on the market.

 

Here's my take on it.

Drilling removes mass from the rotor. Less mass means it can absorb less heat. That means for a given amount of use (i.e. given amount of heat from friction), you are going to have higher rotor temps with a drilled rotor than with a blank rotor.

Rotors are cooled by air flowing in the center hub, through the vanes between the rotor faces, and out the edge of the rotor. Not by having speed holes in the rotor faces.

Drill holes were never added to rotors as a cooling mechanism. They were added to address outgassing, where brake pads release gases at high operating temp. These gases would prevent the pad from fully contacting a standard blank rotor face, so drill holes were added to the rotor to relieve the gas bulidup and restore pad-rotor contact. Modern brake pad compounds do not have this problem anymore.

Slots are a more modern way of addressing the problem, since a properly slotted rotor is less likely to crack than a drilled rotor. But again, the problem doesn't exist anymore, so slots are rather useless as well. Pad "wiping" is not really a good thing unless you simply prefer buying pads more often.

It's up to you who you want to believe. Go have a look around the paddock at "insert road racing event here" and see what kind of rotors are on the racecars. You will find a whole lot of quality *blank* rotors... and maybe some really cool carbon-ceramic stuff.

There's nothing wrong with having drilled/slotted rotors if you want it for looks. But it is not a performance upgrade. A rotor is a friction surface and a heatsink. Anything that hinders those two functions is not a performance mod.

[Yes I realize I am a noob on the Driver, so this post might be met with a "who the hell is that guy?" reaction. Allow me to state that I roadrace a 3000GT VR-4 which is not lightened at all -- it weighs a hair over 3800lbs without driver.

If anybody needs good brakes, and a good understanding of how they work, I do.]

 

damn getting even more confused, so pretty much slotted and drilled rotors are more for looks than performance?? and you would recommend just he normal rotors no drilled or slotted? i hear slotted is the nicest way to go for grabbing better but everyone has different opinion. still dont know what kind of rotors to go for

 

Yes to both questions.

Drill/slot features are something that the automotive aftermarket has sold as a "high performance" feature for so long that it is simply entrenched in buyers' minds. People expect those features in a high performance rotor without questioning their purpose, and upon seeing a drill/slot rotor assume it is a high performance braking system (i.e. "check out that brake bling"). There was a time when drill/slot features served a purpose (when pad outgassing was an ongoing problem), but that time has passed.

So then, why have drill holes and slots if outgassing is not an issue? I can't think of a good reason to intentionally remove mass from a rotor which reduces its thermal capacity and causes the rotor to run hotter.

Once again... people who run their cars on the road course put their brakes through more work/use/abuse than any other thing you can do with a car. What rotors do they use? Quality blank rotors.

That said, you can get away with some brake bling if you are not putting your brakes through hell. But then the question I would ask is: do you want to pay more for a rotor that looks "better" but does not perform as well as a blank rotor? Isn't the point of spending money on the car (especially on the brakes) to make it perform better?

IMO the money one would spend on fancy rotors is much better spent on high quality pads that are appropriate for your car's intended use (I like Porterfield pads and *love* Carbotech), racing brake fluid (ATE Super Blue / Type 200 is my flavor of choice here) and stainless brake hoses to replace the rubber ones. Those parts combined with quality blank rotors would result in the best performance per dollar on an otherwise stock braking system.

Last thing to consider before spending gobs of money on brakes:

Brakes stop the wheels. Tires stop the car. How good are your front tires?

 

front tires are pretty good got them like 3 months ago, would u recommend me goin for the oem rotors? cant find a good blank after market rotor

 

OEM rotors are fine and the only reason i went with XD+S is for looks.. and yes i have R1 premium rotors, which is the same blank as Stoptech slotted rotors (both from Centric), so performanice-wise they are the same. Yes i have heard they rust, but when you buy them just spray them with high-temp paint (Dupli-color clear) before you install them. I've done many carwashs and even driven my car through huge thunderstorms without having any rusts

 

Yes I would recommend an OEM or OEM-equivalent blank rotor... avoid the cheap china/ebay type though.

 

Centric Premium rotors are excellent OEM-blank equivalents, and can be found on Everythingg35.com. FYI - They are also the blanks used by R1 before they drill/slot them.