[MonzaRacer]

Basically going along with what turbulence said. As a rule of thumb unless you're driving a Carrera GT, you don't need drilled rotors.

They just seem structurally weaker compared to slotted rotors in most aftermarket brands since so much more metal is taken off the rotor itself. Dunno how true this is but it seems kinda right.

[Edited by MonzaRacer on Oct 31, 2004 10:04 AM]

 

[JeremyL]

new 2000 tiburon w/auto and package 5: $17,000. parts for auto to manual swap: $2500. spending 6 days under your car with your best friend doing what everyone told you you couldn't do: priceless.

if you bought it brand new why didnt you just buy it with a 5spd?

We have one on the lot now for $14,500

But back to the original topic, the rotors themselves really are the last part of the braking system that one should spend a lot of money (imo anyway) upgrading your tires will do so much more for your stopping than any brake mod. for a street driven car slotted/drilled lets really face it is basically only cosmetic for 99% of the people.

 

[GregsterGSi]

I've seen those cheap ass cross drilled slotted crap fail at the track. Didnt seem like fun. Don't cheap out on brakes.

On my Neon I only use Brembo Blanks, they are high quality and do no insta warp like the made in china rotors. I use Hawk HP+ or Black pads. 3 sets a year of pads and rotors.

Investing in a good set of pads makes a world of difference, but with higher heat you should change the fluid to a dot 4, I recommend Motul RBF

Although Raybestos makes slotted and cross drilled rotors now for dirt cheap and they are high quality.

 

[IN4PAYBACK]

the original post is pretty accurate but for a few things. the bite is said to drop when you have drilled rotors. true because the holes create air pockets that create a buffer beween the pad and rotor...more efficient with slots since the slots extend along the surface of the rotor farther than the pads can reach, thus allowing gases to escape, but...and this is the kicker, with less surface contact between rotor and pad due to holes/slots, a greater bite is achieved. example. adidas on ice=bad idea. skates on ice=good idea. less surface contact means a much higher lb/in2 ratio. with pads and rotors though, this happens on a molecular level (hence the type of friction that is created). the original post is accurate for your more typical pads designed for solid rotors (but better with slots), but higher performance pads have less off gassing and make them more appropriate for drilled rotors. to add one more thing to the original post...temp of pads/rotors is proportional to off gassing. the hotter they get, the more release. im a materials engineer for vt technologies and work specifically with the compounds used in most brake pads (but using them for accoustic reasons instead).

 

[mandarin77]

Availability of Slotted and/or Drilled rotors

DBA rotors are now available in the USA (the last post regarding these was 2004). They have a few options for the Elantra at least. I have not investigated all the other models. The Tiburon is usually the first one it is made for, so we have gotten beyond the first stage of interest. After browsing the webpage and investigating the tech, I am more inclined to use these rotors than Brembo's. (I can't get the two piece rotors, but I can't from Brembo either)

Brembo should have slotted or drilled Sport replacement rotors for the front at least on an Elantra (and Tib). The rear may not be available factory from Brembo, but I have such a hard time finding what I need to know on the Brembo webpages, that I may end up calling the 1-800 number to find out all the part numbers and slotted/drilled availabilities. Then I will have something to work with when I call a retailer. Even the catalog is a few years old on the Brembo webpage.

mandarin

 

[FASONATA]

Okay, my head hurts after reading through most of this information so here's a short version of what you should know. I'm considering auto-xing my ride(ok, you don't need to know that), and input from a seasoned road racer supports a lot of what has been presented here. He runs slotted rotors with really good (race) pads. He tried slotted & drilled with no luck (cracked).

He agrees:
-to avoid slotted & drilled
-drilled as cast (meaning not aftermarket drilled) are good when used with hi-po pads
-changing to a hi-po brake fluid is needed
-really good tires and suspension mods play a big role in braking
-breaking in the brakes is important
-and finally that how you apply the brakes is important.

One last bit, I don't recall if anyone mentioned this source: Performance Brakes - Brake Pads, Brake Rotors and Brake Kits
I came across them in the back of Road & Track, checked out their site and was excited to learn that a company makes drilled rotors for my ride for front and rear -remember, drilled are good if made that way as original AND if you use hi-po pads.

 

[housefull]

First off...I'd like to say.... ^^^^ word. :smoking:

You guys didn't really mention this, but if blank rotors were slotted, is the integrity of the wheel compromised as well as if it were being drilled? Granted, you're not cutting a deep gash into the rotor, but you're altering the physical form of the rotor. In other words, the rotor wasn't really constructed with slots in the first place. So...would there really be this kind of problem with slotting blank rotors?

 

[FASONATA]

Sorry, I know this is old, but here goes. No, slotting blank rotors does not seem to be as much of an issue as drilling holes all the way through.

 

[Andy Friant]

Thanx Autobot for some very useful info. I am always open to learning.

 

[geezer101]

I bought a pair of front cross drilled and slotted rotors off ebay - cheap ones. The slots went all the way to the outer edge of the rotors. Some have a slot that is a few mm short of the edge, and this allegedly prevents gas laminating between the disc and pad escaping. The rotors themselves appear to be made of the same cast metal of OEM/solid face vented rotors. Things I have noticed - the disc faces wear unevenly. Where the drilled vents are, the rotor metal wears faster. It eventually leaves 'ripples' on the face of the rotors. This indicates there is more pressure being applied to the disc through the pads. They are rough on pads too. Pad life has decreased (my 'enthusiastic' driving habits are mostly to blame lol) This also backs up the theory that the cross drilling encourages more force/friction due to the reduction in surface area. Basic law of physics - same force applied to smaller surface area = increased pressure. You get an improvement in brake 'bite'. The holes aren't 2 dimensional - they are like a negative cylinder. The cylindrical 'wall' that makes the hole has a surface area and that increase of surface area improves heat dissipation. I can run these rotors harder than the stock vented rotors and they have a faster cool down recovery time. The brakes help, but if you want an instant improvement in braking buy a decent tyre and wheel upgrade. The J2/RD Lantra runs tiny 14" wheels with 175/65 tyres. I've upgraded to 16x6JJ with 205/50's and even using cheap Chinese low profile tyres are a marked improvement in road grip. I have used Brembo composite pads. They did grab well, but not only was their serviceable life shorter than some pads I have used the brake pad dust was diabolical.