im running a set of slotted, & cross dimpled rotors (they arent fully drilled threw, but are dimpled)
im running a set of slotted, & cross dimpled rotors (they arent fully drilled threw, but are dimpled)
Originally Posted by Nikola Tesla
Blanks ftw!
I compiled similar research about drilled rotors, but everything I found was either indifferent or in favor of slotting. I'll see if I can dig it up.
Found the thread :http://www.sr20-forum.com/members-ri...e-upgrade.html
Post #22 is where the research is and where the conversation gets good: http://www.sr20-forum.com/members-ri...tml#post167293
Tons of people in the field in favor of slots.
No one in favor of holes (obviously).
@Yahnozha
Good point makes sense. I was going off of stuff I knew. Thanks for the info!
Anyways
Im running CD/Slot (irotors brembo blanks cd and slotted, which brembo will either CD or Slot, so it would seem they can stand the stress)
Very good read. thanks!
you have no idea how BAD i want to bump that thread for peoples stupid info on slotted/dimpled rotors. if you want to be cool, its all fine and dandy, but i will keep my blanks thanks much.
I have slotted and crossdrilled rotors on my p10. Honestly, braking is LESS effective than that of the stock rotors. Figured "less surface area" was the cause. Also, the slotted rotors tend to be very noisy on my rears. If I get any motivation, i'll change them out for blanks.
Oh, my Mercedes has crossdrilled rotors on the fronts....from the factory that way. Even at 4200 lbs, that car stops! I believe they are 13" in the front and 11.8" in the rear....huge!
i dunno
Original Owner '95 G20 (from 1995-2010)
suburban & tahoe - thirsty V8's.
awesome info. i had no idea it was that complicated
where can I buy blank brembo rotors? any websites?
After driving with drilled discs I went back to blanks. MUCH better!
really? on the BABK?
at the end of the day it is still the car owner's choice if they want the looks, the performance, or if they just want it to last long. this was written to inform you of the pros and cons. not everybody drive the same so not everybody brake the same. people should get to know their cars more, and not because they read about it.
Nice topic and so true
P11-144SW, VE, B15 LSD swap, DV9, SS/AS exhaust 2.5'-2.25'. AEM ATE B15-Rad B&A BC-Racing BF-Goodridge Bosch Brembo Bride-Brix-II Cusco D-1 DEI Dietz ES Fastbrakes Flexalite Greddy H&R Injen Innovate JWT Magnaflow NGK Nismo Nology Optima Progress Project-Kics Rays Sachs SCE Sparco SSAC Stillen Taylor Valvoline.
No BABK. 280mm rotors with 4 pot S14 calipers.
I had drilled rotors originaly on my CS-BABK but changed to blanks. So much better and much more stable. Now I'm lookinfg at a D2 kit....
P11-144SW, VE, B15 LSD swap, DV9, SS/AS exhaust 2.5'-2.25'. AEM ATE B15-Rad B&A BC-Racing BF-Goodridge Bosch Brembo Bride-Brix-II Cusco D-1 DEI Dietz ES Fastbrakes Flexalite Greddy H&R Injen Innovate JWT Magnaflow NGK Nismo Nology Optima Progress Project-Kics Rays Sachs SCE Sparco SSAC Stillen Taylor Valvoline.
NICE pat, super... i've always wondered wtf was up with rotors , cuz from a physics point of view holes and slots made no sence, thanks man :-) great info
The primary problem with that philosophy is that cast iron conducts heat very slowly to air. If the brake rotors were being run in the water, the extra surface area created by the holes could be beneficial, but the primary responsibility of the rotor is to be a heat sink, and more mass = bigger heat sink.
Highly thermally conductive materials like aluminum and copper are another story entirely, if your brake rotors were made out of one of those, they would conduct heat to air much faster, but they wouldn't be able to take as much heat or use because the material is too soft to absorb the energy via friction.
For people running stock brakes, or even more exotic ones, like the Wilwood kit on the front of my '02 G20 Sport (made by P@, no less). I highly recommend replacing the rotors every time you do the brakes, if you do any sort of extended braking performance driving. For me, it's a no-brainer, I drive 10-15 minutes down windy, braking intensive roads every time I leave the house. I can go through a set of RT-615 Azenis in about 3-5000 miles most of the time.
For $140, I can have rotors and pads for the front of the G. Doing that about once every 6-12 months, keeps me in perfect brakes with maximum heat potential.
Cross-drilled rotors crack, for the most part. Slotted also removes material and cracks. If I'm running stock breaks, I replace the rotors every time I change the pads, rockauto.com or napa locally usually have rotors for 20-$30 a piece all day long, so again, it's cheap insurance.
Turning your rotors is fine if you're not concerned about maximum heat-sink mass. I don't turn rotors, because it's about half the price of brand new rotors, and I'd rather have the mass. Surface area has absolutely nothing to do with mass. Swept area is great for one-time stoppage, it can transfer more energy to the rotors as heat, faster, but if you're heat sink isn't big enough to take it, it doesn't matter anyway.
The biggest factor in single-stop efficiency is tires anyway. Sticky tires stop faster, 50,000 mile all-seasons don't stop very well at all, and ABS is slower (longer stopping distance) than threshold braking all day long.
Assuming you have sticky tires already, brake rotor mass is the next limiting factor, but only on repeated stops. Single-stop, stock brakes will lock up your tires just as well as a 4-piston Wilwood kit, the difference is, the Wilwood's will do that repeatedly, whereas stock rotors will run out of mass to pump the heat into much faster. Pads designed for the temperature range your brakes are going to run at will help that, but if you've got 1600F pads, they chew the rotors alive at 350F.
Peter
Well where to start...
In a stagnant environment (no air is moving) sure. More surface area the better. However in a moving environment, (fans, air etc... that is moving) having holes actually does help. It gives more "surface" to expel heat.
For example. Since normaly when breaking your rotors are moving thus the air is moving over them. The holes now act as "fins" the more fins the better. (go look at a computer processor heat sink)
By it self this will disapate heat ALOT better than if it were a huge block of metal. (such as a rotor...) By adding the holes it creates these "fins"...
I know my logic is a bit hard to follow. And in most real world average joe cases these holes do not help that much.
But really think about it... more surfaces because now you have the inside of the rotor so for a 1/4" hole you now might have twice as much surface area for air to contact with and cool the rotor...
never run with x-drilled or slotted.. why pay more for less?
the ultimate deciding factor on this "bling" is disposable income. i don't have much of it, so i stick with good quality oe replacements. they cost less and do a better job of what they are made for - stopping the car.
paint is a fashion thing, so are wheels, but brakes? not very noticeable unless you are rocking some very thin spoke wheels. paint your calipers yellow if you want extra attention in that area...
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