View Full Version : Drilled/Slotted/etc Rotors
Soulburner
04-18-2006, 09:26 PM
Tired of seeing people on here advocate these and try to come up with reasons why they are better, so here is the truth...
http://www.superchargersonline.com/content.asp?ID=98
Which is why i'll be going with blank Brembos...
Rippthrough
04-19-2006, 01:42 AM
Always makes me laugh when I see people with drilled discs :stick:
Unless it's a Porsche/bike don't buy them
Crazy Chuckster
04-19-2006, 09:39 AM
Those are speed holes, to make you go faster :)
WesM63
04-19-2006, 10:03 AM
That article is exactly right, however I have never seen nor heard of anyones crossdrilled and slotted rotors crack like the images they show'd. (everyone on my porsche forums does some sort of racing) I think the cracking is more of a myth or more previlant in cheaper rotors.
[XC] leviathan18
04-19-2006, 12:08 PM
wesm63 i think that happens if you drill your rotors
something in the lines of im cheap i dont want to buy brembos GT let me cross drill my stock rotors...
if you have a heavy car and do some kind of racing drilled rotors will help to prevent faint due to heat also you have less weight in the car xD
Actually in theory the purpose of the holes is to improve heat dissipation. However 99% of all brake rotors produced today are straight vaned. This means that the ventilation slots go directly from the outer edge of the rotor, towards the centre point of the disc. So there is no benefit in through drilling brake rotors (and inevitably add stress risers) which do not have the vane system designed in a “scoop” fashion (which draws air through the centre core of the disc).
whats the deal with bikes then? ive never seen a modern sport bike (or street biek for that matter)wiht solid rotors. are they jsut using the old style fabircation and need it for the heat dissapation? maybe it has something to do with the floating rotor and design needs?
Bikes rotors are designed differently from cars' rotors and have not vanes. In that case, through holes help quite a bit. Also consider that a motorcycle wheel doesn't run always perpendicular to the ground and the airflow around the surface of the rotor varies depending upon the inclination angle.
Soulburner
04-19-2006, 08:16 PM
That article is exactly right, however I have never seen nor heard of anyones crossdrilled and slotted rotors crack like the images they show'd. (everyone on my porsche forums does some sort of racing) I think the cracking is more of a myth or more previlant in cheaper rotors.
It's no myth...i've seen several examples on my LSX forums of drilled rotors developing little cracks around the holes. And these are quality parts, nothing "DIY". The fact of the matter is, you can't get any benefit out of it on the street so just don't do it. Unless of course you like the looks, and are willing to deal with the consequences such as cracking and eating your brake pads like a cheese grater.
Bikes rotors are designed differently from cars' rotors and have not vanes. In that case, through holes help quite a bit. Also consider that a motorcycle wheel doesn't run always perpendicular to the ground and the airflow around the surface of the rotor varies depending upon the inclination angle.
dunno about you car guys but the new fad in brakes for bikes is the wave rotor. i got them on my track bike, and aside from being lighter, they ahve tons more bite, only with seemingly a lot less surface area. i always had it explained to me that an edge gives more bite than the flat surface of a rotor, and that the holes were drilled to give more edge area. made sense when the wave rotros ahve out that these have tones more edge. is that jsut a common misconception you think? i heard one guys say the desgine simply stays flat under stress give you more surface area. never heard anythign ot back this up, or from anyone else
http://www.twobros.com/Perf_Products/Brake/Galfer_Wave_Rotor-ATV.jpg
Crazy Chuckster
04-20-2006, 03:43 AM
dunno about you car guys but the new fad in brakes for bikes is the wave rotor. i got them on my track bike, and aside from being lighter, they ahve tons more bite, only with seemingly a lot less surface area. i always had it explained to me that an edge gives more bite than the flat surface of a rotor, and that the holes were drilled to give more edge area. made sense when the wave rotros ahve out that these have tones more edge. is that jsut a common misconception you think? i heard one guys say the desgine simply stays flat under stress give you more surface area. never heard anythign ot back this up, or from anyone else
http://www.twobros.com/Perf_Products/Brake/Galfer_Wave_Rotor-ATV.jpg
Those are only meant to stop a couple hundred pounds at most. They would never work on something like a motorcycle and up.
JasonDTM
04-20-2006, 05:08 AM
^^^ He rides a motorcycle... :(
The main benefit of cross-drilling a brake rotor is unsprung weight. Drilled rotors are bound to develop cracks around the hole, As long as they are surface cracks and the rotor isn't warped you should be fine.. I few people I know with 911's have the Brembo Big Red conversion and they're still using the rotors supplied with the kits and thats after about 10 track days..
Rippthrough
04-21-2006, 11:27 AM
Those are only meant to stop a couple hundred pounds at most. They would never work on something like a motorcycle and up.
They work on motorcycles and they're on a couple of rally cars too. No real braking benefit, but they give the same braking force with less unsprung rate than standard discs. Eat pads though.