Cross Drilled Rotors
06-18-2008, 04:18 PM
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My Ride: Stock '08 550i with the M5 aerodynamic OEM package
OK guys - I've read about every thread there is about getting cross drilled rotors on my new '08 550. One guy says they're a direct fit off of an M5 while others say (including my BMW parts guy) that it's a mess and a whole lot of parts need to be exchanged.
Now all I want to figure out is a definitive answer on the simplest way to get cross-drilled rotors on this car without spending an arm & a leg.
Thanks for any advice, suggestions or even answers!
Now all I want to figure out is a definitive answer on the simplest way to get cross-drilled rotors on this car without spending an arm & a leg.
Thanks for any advice, suggestions or even answers!
06-18-2008, 04:38 PM
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My Ride: 2008 535i: June 6th start build, complete June 17th, at NY Port July 5th, at dealer July 10th, took delivery Friday July 13- Plantimum Bronze/Natural Brown Leather/Light Poplar, Sport Package, Sport Auto, Active Steering, Premium Package, CWP & PDC. Dinan Performance Software 384hp & 421 ft/lbs.
Sorry for going astray- Why do you think you need M5 brake rotors? They will add to your unsprung weight of each wheel. For a given sized rotor, every hole decreases frictional (stopping) surface area which means less braking power. Drilled or slotted rotors basically cut the brake pads slightly faster so you have a softer surface.
Drilled rotors do look Bling, but are you having a problem?
Drilled rotors do look Bling, but are you having a problem?
06-18-2008, 05:33 PM
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Pennetta is right 
"...Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40?s and 50?s, not a whole lot. Rotors were first ?drilled? because early brake pad materials gave off gasses when heated to racing temperatures ? a process known as ?gassing out?. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ?somewhere to go?. It was an effective solution, but today?s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don?t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads ? sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)"
I still like mine though
"...Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40?s and 50?s, not a whole lot. Rotors were first ?drilled? because early brake pad materials gave off gasses when heated to racing temperatures ? a process known as ?gassing out?. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ?somewhere to go?. It was an effective solution, but today?s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don?t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads ? sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)"
I still like mine though
06-18-2008, 06:42 PM
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Originally Posted by Rizbel' post='605468' date='Jun 18 2008, 09:33 PM
Pennetta is right
"...Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40?s and 50?s, not a whole lot. Rotors were first ?drilled? because early brake pad materials gave off gasses when heated to racing temperatures ? a process known as ?gassing out?. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ?somewhere to go?. It was an effective solution, but today?s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don?t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads ? sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)"
I still like mine though
"...Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40?s and 50?s, not a whole lot. Rotors were first ?drilled? because early brake pad materials gave off gasses when heated to racing temperatures ? a process known as ?gassing out?. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ?somewhere to go?. It was an effective solution, but today?s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don?t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads ? sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)"
I still like mine though
Good post. I was taken back in laughter at the end of it. All those words taking us in one direction and then, BAM. U turn. I happen to like them too. I've found them for our cars as a direct OEM replacement. I think they were about $225 a pair. Still havent pulled the trigger. If you're interested in what I found Lizard, let me know. I have the websites in my office.
06-18-2008, 07:02 PM
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Originally Posted by poleposition' post='605503' date='Jun 18 2008, 09:42 PM
I happen to like them too. I've found them for our cars as a direct OEM replacement. I think they were about $225 a pair. Still havent pulled the trigger. If you're interested in what I found Lizard, let me know. I have the websites in my office.
Thanks in advance
06-18-2008, 07:42 PM
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Originally Posted by poleposition' post='605503' date='Jun 18 2008, 09:42 PM
Good post. I was taken back in laughter at the end of it. All those words taking us in one direction and then, BAM. U turn. I happen to like them too. I've found them for our cars as a direct OEM replacement. I think they were about $225 a pair. Still havent pulled the trigger. If you're interested in what I found Lizard, let me know. I have the websites in my office.
06-19-2008, 01:41 AM
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Do you want your car a) looks better with drilled rotors or do you need to b) improve your braking power ?
a) ebay.com and you will find rotors for the 550i size
b) M5 brakes
a) and b) M5 brakes
a) ebay.com and you will find rotors for the 550i size
b) M5 brakes
a) and b) M5 brakes
06-19-2008, 01:52 AM
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IVE NOTICED THAT The cross drilled or grooved rotors actaully omproved my braking especially on highways when hitting down hard
the downside is, it makes the wheels so dirty...so fast...i have to clean my wheels every 5-6 days compared two weeks when i had stock padsand stock rotors........
the downside is, it makes the wheels so dirty...so fast...i have to clean my wheels every 5-6 days compared two weeks when i had stock padsand stock rotors........
06-19-2008, 01:54 AM
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Originally Posted by Rizbel' post='605468' date='Jun 19 2008, 08:33 AM
Pennetta is right
"...Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40?s and 50?s, not a whole lot. Rotors were first ?drilled? because early brake pad materials gave off gasses when heated to racing temperatures ? a process known as ?gassing out?. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ?somewhere to go?. It was an effective solution, but today?s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don?t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads ? sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)"
I still like mine though
"...Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40?s and 50?s, not a whole lot. Rotors were first ?drilled? because early brake pad materials gave off gasses when heated to racing temperatures ? a process known as ?gassing out?. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ?somewhere to go?. It was an effective solution, but today?s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don?t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads ? sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)"
I still like mine though
shame..
06-19-2008, 02:35 AM
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Originally Posted by Rizbel' post='605468' date='Jun 18 2008, 06:33 PM
Pennetta is right
"...Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40?s and 50?s, not a whole lot. Rotors were first ?drilled? because early brake pad materials gave off gasses when heated to racing temperatures ? a process known as ?gassing out?. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ?somewhere to go?. It was an effective solution, but today?s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don?t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads ? sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)"
I still like mine though
"...Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40?s and 50?s, not a whole lot. Rotors were first ?drilled? because early brake pad materials gave off gasses when heated to racing temperatures ? a process known as ?gassing out?. These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses ?somewhere to go?. It was an effective solution, but today?s friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. Contrary to popular belief they don?t lower temperatures (in fact, by removing weight from the rotor, the temperatures can actually increase a little), they create stress risers allowing the rotor to crack sooner, and make a mess of brake pads ? sort of like a cheese grater rubbing against them at every stop. (Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it.)"
I still like mine though
Thanks,
Cal