drilled or drilled & slotted rotors
Winching
Joined: Jun 2009
Posts: 692
Likes: 9
What exactly are drilled or slotted rotors going to do for a truck, other than wear out brake pads faster and make more dust?
I have them on my track car, and can't tell the difference when driving it on the street. Even when I'm driving it way harder than anyone ought to be driving a 2.5 ton 4 wheel drive truck. The only time they make a noticeable difference is when I'm getting close to brake fade (on the track, with very hard track pads).
I have them on my track car, and can't tell the difference when driving it on the street. Even when I'm driving it way harder than anyone ought to be driving a 2.5 ton 4 wheel drive truck. The only time they make a noticeable difference is when I'm getting close to brake fade (on the track, with very hard track pads).
Last edited by DarylJ; Jul 5, 2011 at 08:28 AM.
Drifting
Joined: May 2010
Posts: 32
Likes: 0
From: Western NY
I got new rotors and ceramic pads all the way around and the price was relatively good, but I opted for solid rotors for the braking power: Brake Rotors Discs Pads Brakes Cross Drilled & Slotted
Three Wheeling
Joined: Jun 2011
Posts: 56
Likes: 1
From: Virginia
What exactly are drilled or slotted rotors going to do for a truck, other than wear out brake pads faster and make more dust?
I have them on my track car, and can't tell the difference when driving it on the street. Even when I'm driving it way harder than anyone ought to be driving a 2.5 ton 4 wheel drive truck. The only time they make a noticeable difference is when I'm getting close to brake fade (on the track, with very hard track pads).
I have them on my track car, and can't tell the difference when driving it on the street. Even when I'm driving it way harder than anyone ought to be driving a 2.5 ton 4 wheel drive truck. The only time they make a noticeable difference is when I'm getting close to brake fade (on the track, with very hard track pads).
the short answer is - they are not necessary 99% of the time today because most brake pads do not have problems with off-gassing.
Rock Crawling
Joined: Sep 2006
Posts: 495
Likes: 0
From: Colorado
Winching
Joined: Jun 2009
Posts: 692
Likes: 9
I agree. The only reason they are run on the track is that a lot of the very hard track pads (the ones that barely work at all when cold) have a gassing problem once they start getting very hot. Which is why I run them on the track car but nothing else.
Administrator
Joined: Apr 2006
Posts: 25,707
Likes: 107
From: Denver, Colorado
The only good slotted and drilled rotors are DBA rotors out of Austrialia, I currently have nearly 100,000 miles on my along with some Akebono ceramics and boy they will outstop convential rotors and last for ever.
Mudding
Joined: May 2011
Posts: 173
Likes: 1
Here's some kit:
04 2004 Land Rover Discovery Brake Rotor - Brake - Brembo, PBR, Pilenga, Beck Arnley, Pronto, Rear, Front - PartsGeek
EBC kits: 04 2004 Land Rover Discovery Brake Rotor Set - Brake - EBC, Front, Rear - PartsGeek
Drilled and slotted rotors are for escape of gas and dust but have reduced friction surface and reduced mass, which in turn reduces the rotor's ability to absorb heat (which is how it works, by turning force into heat).
Drilled rotors collect mud and don't shed it. Slotted or dimpled rotors are better for mud as they hold less of it.
Vented rotors are far better than either slotted or drilled rotors without venting, for the street. Vented rotors are probably very poor for mud deep enough to encase them.
Although Partsgeek advertises vented rotors for the Land Rover, I don't see how they can make them fit in the stock calipers unless the rotor surfaces are very thin. The mass would also necessarily be reduced which is not good. You really want a much thicker vented rotor to allow sufficient mass and still provide vent space, but this means a wider caliper.
At the end of the day, they don't really make racing brakes for Discoveries because they're for off-road where you use low gear and engine braking, not so much wheel brakes. For the street, there's the Range Rover: http://www.roverparts.com/Parts/BRM03.cfm
04 2004 Land Rover Discovery Brake Rotor - Brake - Brembo, PBR, Pilenga, Beck Arnley, Pronto, Rear, Front - PartsGeek
EBC kits: 04 2004 Land Rover Discovery Brake Rotor Set - Brake - EBC, Front, Rear - PartsGeek
Drilled and slotted rotors are for escape of gas and dust but have reduced friction surface and reduced mass, which in turn reduces the rotor's ability to absorb heat (which is how it works, by turning force into heat).
Drilled rotors collect mud and don't shed it. Slotted or dimpled rotors are better for mud as they hold less of it.
Vented rotors are far better than either slotted or drilled rotors without venting, for the street. Vented rotors are probably very poor for mud deep enough to encase them.
Although Partsgeek advertises vented rotors for the Land Rover, I don't see how they can make them fit in the stock calipers unless the rotor surfaces are very thin. The mass would also necessarily be reduced which is not good. You really want a much thicker vented rotor to allow sufficient mass and still provide vent space, but this means a wider caliper.
At the end of the day, they don't really make racing brakes for Discoveries because they're for off-road where you use low gear and engine braking, not so much wheel brakes. For the street, there's the Range Rover: http://www.roverparts.com/Parts/BRM03.cfm
Last edited by nevada ben; Jul 5, 2011 at 06:13 PM.
Administrator
Joined: Apr 2006
Posts: 25,707
Likes: 107
From: Denver, Colorado
Ben, do you have slotted and drilled rotors, have you ever see your drilled hole pack with mud, it really doesn't happen, more of an old story passed around by people who don't have first hand experience.