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Initial D World - Discussion Board / Forums > Technical Discussion > Myth Busting: Crossdrilled Rotors


Posted by: But she looked 18 officer May 15 2005, 03:52 PM
QUOTE
(Taken from a sticky at Celicatech)
Since I know folks will be eventually asking about this I figured it
would be better to head off this disaster before it gets ugly. Here is
the response I made to a different forum a few months ago after
collecting some information:

===========
First, lets get some physics. Tell me how a heatsink with less mass will
cool better? You do realize that a brake rotor acts as a large heatsink
to transfer heat from the brake pads to the rotor. The heat generated
from pads has to go somewhere and so it transfers to the rotor and
caliper.

Porsche claims: "Discs are cross-drilled to enhance braking in the wet.
The brakes respond faster because the water vapour pressure that builds
up during braking can be released more easily."
They have said nothing about enhancing normal braking circumstances and
the larger diameter rotors probably make up for the lack of material
present in a smaller cross drilled rotor.

From Wilwood's website:
QUOTE
Q:  Why are some rotors drilled or slotted?
A: Rotors are drilled to reduce rotating weight, an issue near and dear
to racers searching for ways to minimize unsprung weight. Drilling
diminishes a rotor's durability and cooling capacity.
Slots or grooves in rotor faces are partly a carryover from the days of
asbestos pads. Asbestos and other organic pads were prone to "glazing"
and the slots tended to help "scrape or de-glaze" them.  Drilling and
slotting rotors has become popular in street applications for their pure
aesthetic value. Wilwood has a large selection of drilled and slotted
rotors for a wide range of applications

As for the Porsche rotors..
QUOTE

1) The holes are cast in giving a dense boundary layer-type crystalline
grain structure around the hole at the microscopic level as opposed to
drilling which cuts holes in the existing grain pattern leaving open
endgrains, etc, just begging for cracks.
2) The holes are only 1/2 the diameter of the holes in most drilled
rotors. This reduces the stress concentration factor due to hole
interaction which is a function (not linear) of hole diameters and the
distance between them.
3) Since the holes are only 1/2 as big they remove only 1/4 as much
surface area and mass from the rotor faces as a larger hole. This does a
couple of things:
It increases effective pad area compared with larger holes. The larger
the pad area the cooler they will run, all else being equal. If the same
amount of heat is generated over a larger surface area it will result in
a lower temperature for both surfaces.
It increases the mass the rotor has to absorb heat with. If the same
amount of heat is put into a rotor with a larger mass, it will result in
a lower temperature.
3) The holes are placed along the vanes, actually cutting into them
giving the vane a "half moon" cut along its width. You can see that
here:
user posted image

This does a couple of things:
First, it greatly increases the surface area of the vanes which allows
the entire rotors to run cooler which helps prevent cracks by itself.

Second, it effectively stops cracking on that side of the hole which
makes it very difficult to get "hole to hole" cracks that go all the way
through the face rotor (you'll get tiny surface "spider cracks" on any
rotor, blank included if you look hard enough).

That's why Porsche rotors are the only "crossdrilled" rotors I would
ever consider putting on my car.

BTW, many of the above features are not present in older Porsche brakes.
The above is for "Big Reds" and newer.


This is quite different from the standard drilled rotors you get from
brembo/kvr/powerslot/"insert random ricer parts brand name here" brake
rotors.

Further proof of the uselessness of cross drilled rotors are found here:
http://www.teamscr.com/rotors.htm
QUOTE
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.)

The one glaring exception here is in the rare situation where the rotors
are so oversized (look at any performance motorcycle or lighter formula
car) that the rotors are drilled like Swiss cheese. While the issues of
stress risers and brake pad wear are still present, drilling is used to
reduce the mass of the parts in spite of these concerns. Remember –
nothing comes for free. If these teams switched to non-drilled rotors,
they would see lower operating temperatures and longer brake pad life –
at the expense of higher weight. It’s all about trade-offs.


From Stoptech
QUOTE
Which is better, slotted or drilled rotors?
StopTech provides rotors slotted, drilled or plain. For most performance
applications slotted is the preferred choice. Slotting helps wipe away
debris from between the pad and rotor as well as increasing the "bite"
characteristics of the pad. A drilled rotor provides the same type of
benefit, but is more susceptible to cracking under severe usage. Many
customers prefer the look of a drilled rotor and for street and
occasional light duty track use they will work fine. For more severe
applications, we recommend slotted rotors.


That almost sounds like an excuse to use cross drilled rotors, and for
your street car which probably is never driven on the track, the drilled
rotors are fine, but as Stoptech states, they will crack and are not
good for severe applications.

From Baer:
QUOTE
"What are the benefits to Crossdrilling, Slotting, and
Zinc-Washing my rotors?

In years past, crossdrilling and/or Slotting the rotor for racing
purposes was beneficial by providing a way to expel the gasses created
when the bonding agents employed to manufacture the pads...However, with
today’s race pad technology, ‘outgassing’ is no longer much of a
concern...Slotted surfaces are what Baer recommends for track only use.
Slotted only rotors are offered as an option for any of Baer’s
offerings."


Then from Grassroots Motorsports:
QUOTE
"Crossdrilling your rotors might look neat, but what is it really
doing for you? Well, unless your car is using brake pads from the '40s
and 50s, 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." ...It was an effective solution, but
today's friction materials do not exhibit the some gassing out
phenomenon as the early pads. Contrary to popular belief, they don't
lower temperatures. (In fact, by removing weight from the rotor, they
can actually cause temperatures to increase a little.) These holes
create stress risers that allow 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...Slotting rotors, on the other hand, might be a
consideration if your sanctioning body allows for it. Cutting thin slots
across the face of the rotor can actually help to clean the face of the
brake pads over time, helping to reduce the glazing often found during
high-speed use which can lower the coefficient of friction. While there
may still be a small concern over creating stress risers in the face of
the rotor, if the slots are shallow and cut properly, the trade-off
appears to be worth the risk. (Have you looked at a NASCAR rotor
lately?)


And then, let's check out what was said on the aforementioned Altima
thread (Long thread at altimas.net that was deleted by that server. it
is hosted http://corner-carvers.com/altimathread.php.html)

QUOTE
Here is how it works. The friction between the pad and rotor is
what causes you to stop. This friction converts your forward energy into
heat (remember Einstein: Energy is neither created nor destroyed, it is
converted). Now that heat is a bad thing. Yes it is bad for the rotors
but it is a lot worse for the pads. A warped rotor will still stop the
car - it will just feel like shit. Overheated pads however WILL NOT stop
the car. It is here where the rotors secondary responsibility comes in.
Its job now is to DISSIPATE the heat away from the pads and DISPERSE it
through itself. Notice that DISSIPATE and DISPERSE are interchangeable?
Once the heat is removed from the pad/surface area it is then removed.
Notice where the removal falls on the list of duties? That's right -
number 3. Here is the list again. Memorize it because I will be using it
a lot in this post:

#1 Maintains a coefficient of friction with the pad to slow the forward
inertia of the vehicle

#2 DISSIPATE the heat

#3 REMOVE the heat from the brake system

Let's look more in-depth at each step now shall we? No? Too bad assclown
we are doing it anyway.

#1 Maintains a coefficient of friction with the pad to slow the
forward inertia of the vehicle:
This one is pretty simple and self-explanatory. The rotor's surface is
where the pads contact and generate friction to slow the vehicle down.
Since it is this friction that causes the conversion of forward
acceleration into deceleration (negative acceleration if you want) you
ideally want as much as possible right? The more friction you have the
better your stopping will be. This is reason #1 why BIGGER brakes are
the best way to improve a vehicle's stopping ability. More surface area
on the pad and the rotor = more friction = better stopping. Does that
make sense Ace? Good. Let's move on.
#2 DISSIPATE The Heat:
Let's assume for a second that the vehicle in question is running with
Hawk (Seiji) (Seiji) (Seiji) Blue pads on it. The brand doesn't really matter but that is what I
am using as my example. They have an operating range of 400 degrees to
1100 degrees. Once they exceed that 1100 degree mark they fade from
overheating. The pad material gets too soft to work effectively -
glazing occurs. This means that a layer of crude glass forms on the
surface of the pad. As we all know glass is very smooth and very hard.
It doesn't have a very high coefficient of friction. This is bad -
especially when I am coming down the back straight at VIR at 125MPH.
Lucky for us the rotor has a job to do here as well. The rotor, by way
of thermal tranfer DISSIPATES the heat throughout itself. This
DISSIPATION lessens the amount of heat at the contact area because it is
diluted throughout the whole rotor. The bigger the rotor the better here
as well. The more metal it has the more metal the heat can be diluted
into. Make sense? This isn't rocket science here d00d.
#3 REMOVE the heat from the brake system:
Now comes your favorite part of the process. This is what you thought
DISSIPATION was. It is ok. I will allow you to be wrong. This is the
step where the rotor takes the heat it DISSIPATED from the pads and gets
rid of it for good. How does it do this? By radiating it to the surface
- either the faces or inside the veins. It is here where cool air
interacts with the hot metal to cool it off and remove the heat. Once
again there is a reoccuring theme of "the bigger the better" here. The
bigger the rotor, the more surface area it will have which means more
contact with the cooling air surrounding it. Got it? Good.
Now let's look at why cross-drilling is a bad idea.
First - as we have already established, cross-drilling was never done to
aid in cooling. Its purpose was to remove the worn away pad material so
that the surfaces remained clean. As we all know this doesn't have much
of a purpose nowadays.
Next - In terms of cooling: Yes - x-drilling does create more areas for
air to go through but remember - this is step 3 on the list of tasks.
Let's look at how this affects steps 1 and 2. The drilling of the rotor
removes material from the unit. This removal means less surface area for
generating surface friction as well as less material to accept the
DISSIPATED heat that was generated by the friction. Now because of this
I want to optimize step one and 2 since those are the immediate needs.
If it takes longer for the rotor to get rid of the heat it is ok. You
will have a straight at some point where you can rest the brakes and let
your cooling ducts do their job. My PRIMARY concern is making sure that
my car slows down at the end of the straight. This means that the rotor
needs to have as much surface as possible to generate as much friction
as possible and it needs to DISSIPATE the resulting heat AWAY from the
pads as quick as possible so they continue to work. In both cases
x-drilling does nothing to help the cause.
Now let's talk about strength - and how x-drilled rotors lack it. This
one is simple. Explain again just how drilling away material/structure
from a CAST product DOES NOT weaken it? Since you are obviously a man of
great knowledge and experience surely you have seen what can happen to a
x-drilled rotor on track right? Yes it can happen to a non-drilled rotor
as well but the odds are in your favor when pimpin' bling-bling drilled
y0! Since you are also an expert on thermodynamics why not explain to
the group what happens to a cast iron molecule when it is overheated. I
will give you a little hint - the covalence bonds weaken. These bonds
are what hold the molecules together boys and girls. You do the math -
it adds up to fractures.
So why don't race teams use them if they are so much better?
Consistency? Hmmmm . . . no. I am gonna go with the real reason her
chodeboy. It is because of several factors actually. They are as follows
but in no particular order:

- Less usable surface area for generating friction
- Less material to DISSIPATE the heat away from the pads
- Less reliable and they are a safety risk because of fatigue and stress
resulting from the reduced material

And what are the benefits? Removal of particulate matter and enhanced
heat removal. I gotta tell ya - it is a tough choice but I think I am
going to stick with the safe, reliable, effective-for-my-stopping needs
solution Tex.


Thank you, please drive through.

======================

So basically, buy them if you think they look cool, but not if you think
this will be an acceptable performance upgrade.

Posted by: sideways May 15 2005, 05:43 PM
Pin worthy cool.gif but this should probably be in the Tech section, ill let it get some attention here then pin her up in the tech

Posted by: WRX DEMON Type R May 15 2005, 05:59 PM
im too lazy to read all that.

i am looking to completely replace my car's pads and rotors...

Suggestion please?

Posted by: But she looked 18 officer May 15 2005, 06:24 PM
I will suggest you quit being lazy and do some research. There is a LOT more to getting the right braket setup then what many people go by which is "bigger is better".
Think about exactly what it is about your current brakes that you are not satisfied with and what type of driving will your car be experiencing.
FWIW When Brad Bedell's mk2 mr2 won the Sport Compact Car Magazine, Ultimate Street Car Challenge, he was using 94/95turbo mr2 brakes with real good pads and had the lowest stopping distance of any car they had ever tested.
A good set of brake pads can do wonders for your car.
Also remember, brakes dont stop the car, the tires do.

*edit: If your really set on spending money I would suggest going with STi brake setup. They have had a lot of testing done for those cars. You could probably get a good set of 2nd hand brakes from someone with out too much money.

Posted by: Nd4SpdSe May 15 2005, 07:26 PM
I've always wondered then, why do high-performance cars have them?

Lamborghini Murcielago
http://www.swisscarsightings.com/lamborghini/Lamborghini%20Murcielago%20340.jpg

Porsche 911 GT3
http://images.automotive.com/cob/factory_automotive/images/Features/auto_shows/2004_CIAS/2004_Porsche_911_GT3_wheels.jpg

2006 Corvette
http://www.canadiandriver.com/discus/messages/1490/24053.jpg

Enzo Ferrari
http://www-personal.engin.umich.edu/~dixitp/photos/autoshow03/P1180880.jpg

Posted by: sideways May 15 2005, 07:36 PM
To keep it simple because they look good. Nicks post was dead on and used a number of resources, common sense with physics will also support the claims made. They want a car the looks and performs good.

As nick touched, hands down the BEST way to increase your braking ability are the pads. If your getting brake fade due to overheating you need to flush out your system and upgrade your fluid. If you want to upgrade your rotors, sloted is the best path to go. Any thing that builds up between the rotor and the pad has a place to go, plus the egde gives the slicing effect should the pads start to glaze. They suppoedly bring the life of your pads down but its minimal, so no worries- small price to pay for the advantage imo.

NFS i still suggest you upgrade your fluid as well, its not a sin to mix fluid, and as long as you flush it properly youll do fine. Bleed the rear passenger until your getting the new fluid going through, rear driver, front passenger, then front driver (from the furthest to closest).

Posted by: WRX DEMON Type R May 15 2005, 08:25 PM
my brake rotors are rusted (what i get for keeping the car locked up for nearly 3 moths) and the car makes noises when i press the brakes.

hey, anyone know if Monroe brakes are any good? www.monroebrakes.com

I can grab these at Canadian Tire. Rotors and pads.
ATM the car is just for transportation. No fancy NAWZ or drifting for me. LOL.

Posted by: Cubits May 15 2005, 09:10 PM
Slots-b-good. Even the most uber-modern pads will glaze from light pedal use etc, and slots don't really diminish the pad life much. The slots may weaken the disc slightly, but it is quite an insignificant amount in most cases.

Drilled are pretty bad. If you don't get hole-cast discs, it will create issues. If you say, got the brakes nice and hot on a mountain road, then hit a puddle, you'd probably warp or even crack the discs (badness).

I've seen semi-drilled discs (EBC make em) that are slotted too. Pretty sure the hemispherical dents are only for street appeal, but at least they'll be stronger than fully-drilled discs. They're cast holes.

Posted by: Jabberwocky May 15 2005, 10:21 PM
Let me start off by saying that what nick posted was true.

Cross drilled rotors are not without their application. It is a viable way to reduce unsprung weight/rotational mass. Usually a cross drilled rotor of the same thickness will have less mass. Thus be a worst heatsink. In some cases, this trade off is worth it, especially is the car already has more than adequate braking. Eg. if the car can lock all 4 wheels at any time.

The other way to reduce the rotational mass of the rotor is to make it thinner. Which can make it more prone to warping. Or decrease the size of the rotor. Which also reduces the surface area. Reducing the mass of the rotor usually involves some kind of trade off no matter how you look at it.

From what I've seen, high price cars with drilled rotors usually also have massively powerful braking systems. A slight reduction in unsprung weight could very well be worth the tradeoff since the braking system far exceeds the traction of the tires anyways.

I think only cheap pads glaze. The good ones aren't suppose to.

Posted by: Cubits May 15 2005, 11:47 PM
If i had more than sufficient braking, i would rather go to a smaller disc than have holes drilled in them. The saving in rotational inertia is worth a buttload more than the saving in unsprung mass.

Posted by: Jabberwocky May 16 2005, 06:49 PM
I dont want to get too deeply into it, but going with a smaller diameter usually means a small pad. Also the braking force depends partially on the velocity of the rotor relative to the pad. There are tradeoffs to everything. I'm not saying that crossdrilling is better or worse, but that it is another valid way to lowering rotational mass.

Posted by: MidnightViper88 May 16 2005, 07:18 PM
I like the drag racing cue of parachutes...

Posted by: vhsfootball_82 May 16 2005, 07:18 PM
so sloted rotors are better than having crossed-drilled rotors------In heavy racing i think.........
and Having Bigger rotors and Bigger Brake pads, give u better braking........

crossed-drilled rotors look nice, but are more for street/light racing........

and

i dont think having a smaller rotor and smaller pads would help u brake better.......well from what i read in the first post.......Having a bigger rotor surface, will dissipate and dispense heat faster.........

you would have less surface for heat to dissipate into the rotors and heat wont dispense as fast as a bigger one would......i think

correct me if im wrong, im still trying to figure it out, trying to make it easy for others........got to learn this stuff.....its interesting....... cool.gif

Posted by: Jabberwocky May 16 2005, 08:18 PM
It can't be oversimplified too much. I'd just wanted to point out that crossdrill rotors arent complete junk. I use regular blanks myself because they are cheaper and work just as well.

Here's a bunch of factors to consider (generally true):
With larger diameter rotors, you have more rotational inertia, which is very bad.
With larger diameter rotors, you also generally have more mass to resist fad, good.
With larger diameter rotors, you generally have a the pad engage the rotor at a higher velocity, good.
With larger diameter rotors, you generally have the air vanes in the rotor working at a higher velocity to dissapate heat, good.
With holes/slot drilled in, you generally have less pad to rotor contact, bad.
With holes/slot drilled in, you generally have less rotational inertia, good.
With holes/slot drilled in, you generally have less mass to resist fade, bad.
With holes/slot drilled in, you generally have a weaker rotor prone to cracking, bad.
With thinner rotors, you generally have less rotational inertia, good.
With thinner rotors, you generally have less mass to resist fade, bad.
With thinner rotors, you generally have a weaker rotor prone to warping, bad.

That barely scratches the surface. Then there's the tires effect on braking, the caliper design, the brake pad material, the rotor's material, rotor vane design, antisquat and antidive and their effect on weight transfer during braking and more.

I know that I'm not that knowledgeable on brakes either. There is probably plenty of stuff that I haven't even mentioned.

For those looking for more braking power, I'll say this. The biggest factor IMO is brake pad, the difference between el cheapo autozone pads and something like HP+ is just astounding.

Posted by: vhsfootball_82 May 16 2005, 08:36 PM
QUOTE (Jabberwocky @ May 16 2005, 08:18 PM)
It can't be oversimplified too much. I'd just wanted to point out that crossdrill rotors arent complete junk. I use regular blanks myself because they are cheaper and work just as well.

Here's a bunch of factors to consider (generally true):
With larger diameter rotors, you have more rotational inertia, which is very bad.
With larger diameter rotors, you also generally have more mass to resist fad, good.
With larger diameter rotors, you generally have a the pad engage the rotor at a higher velocity, good.
With larger diameter rotors, you generally have the air vanes in the rotor working at a higher velocity to dissapate heat, good.
With holes/slot drilled in, you generally have less pad to rotor contact, bad.
With holes/slot drilled in, you generally have less rotational inertia, good.
With holes/slot drilled in, you generally have less mass to resist fade, bad.
With holes/slot drilled in, you generally have a weaker rotor prone to cracking, bad.
With thinner rotors, you generally have less rotational inertia, good.
With thinner rotors, you generally have less mass to resist fade, bad.
With thinner rotors, you generally have a weaker rotor prone to warping, bad.

That barely scratches the surface. Then there's the tires effect on braking, the caliper design, the brake pad material, the rotor's material, rotor vane design, antisquat and antidive and their effect on weight transfer during braking and more.

I know that I'm not that knowledgeable on brakes either. There is probably plenty of stuff that I haven't even mentioned.

For those looking for more braking power, I'll say this. The biggest factor IMO is brake pad, the difference between el cheapo autozone pads and something like HP+ is just astounding.

very true..........
autozone pads,,,,,,cheapo.......brake pads do make a difference in braking.......big time

Posted by: TaksPandaHatch Sep 10 2005, 12:26 AM
Alright.
The bigger the rotor, the more heat you will disipate, which means less brake fade and not having to turn your rotors because of warpage.
Pads do make a difference. I heard some dumb a$$ at Kragen say that ceramic pads will stop squeeking. BS The squeeking is the brake pads moving in the caliper while braking causing a high pitch sound. Ceramic work better at a high heat range and that is why more cars are using them. While Semi Metallic pads work better at a low heat range.
Now, cross drilled rotors and slotted rotors. Prectically the same.
Cross drilled CAN disipate heat better because the air hits them, but they are taking away metal mass and brake surface area they cannot disipate heat as well because its NOT there. SO you can stop better but you can't either. YOU GAIN and lose.
Some Slotted rotors have more pad surface area, some have less,but for the most part, but you have more metal to help disipate the heat than drilled rotors.

They also BOTH help remove gasses that build up on the pad surface.
Better braking can be achieved by removing the heat, that is the goal of the rotors. You can also increase the rotor size to achieve better braking because you have more brake pad surface area.

Posted by: RandRace Sep 12 2005, 08:50 AM
QUOTE
First, lets get some physics. Tell me how a heatsink with less mass will cool better?


Greater surface area.

Not neccessarily true in regards to drilled rotors where you're not getting any more surface area, but true in a general sense.

Look at the heatsink in your computer. A heavily vaned chunk of aluminum. A solid lump of aluminum would have greater mass and a better ability to absorb heat but far less ability to dissipate that heat since the air flowing over it would pass over a far smaller surface area.

I want rotors with a fractal surface. To the pads it would be just like a normal solid disk. To the air though the surface area would be simply immense. Orders of magnitude greater than the flat surface of the rotor.

Posted by: Pearce Sep 19 2005, 08:36 AM
someone mighta said this...that's too much to read...but i heard hey warp more easier when they're crossed drilled because they heat up really hot and then cool so quickly...heard it from some street racer...not to sure on the validity of his statement, but it does kinda make since

Posted by: MidnightViper88 Sep 19 2005, 03:01 PM
QUOTE (Nd4SpdSe @ May 15 2005, 07:26 PM)
I've always wondered then, why do high-performance cars have them?

Lamborghini Murcielago
http://www.swisscarsightings.com/lamborghini/Lamborghini%20Murcielago%20340.jpg

Porsche 911 GT3
http://images.automotive.com/cob/factory_automotive/images/Features/auto_shows/2004_CIAS/2004_Porsche_911_GT3_wheels.jpg

2006 Corvette
http://www.canadiandriver.com/discus/messages/1490/24053.jpg

Enzo Ferrari
http://www-personal.engin.umich.edu/~dixitp/photos/autoshow03/P1180880.jpg

It's taken quite a few months for me to ponder over this post, but sports and supercars have more than just large-ass brakes...They also have large-ass pads to go with them, large-ass wheels, and wide/sticky-ass tires, so their braking capabilities are not soley on brakes alone...

Posted by: InitialE Sep 19 2005, 03:17 PM
Tire compound/size are more or just as important as brakes when it comes to stopping power, it's the only thing that touches the road surface

Posted by: sideways Sep 19 2005, 03:25 PM
Exotics drill their rotors for one reason. It looks nice, how often do u think those owners are REALLY pushing those cars aroudn tracks? (granted some of them actually DO). That and then of course they dont use the same material to make their rotors.

Posted by: Wheels84ss Sep 21 2005, 06:22 PM
QUOTE (Nd4SpdSe @ May 15 2005, 10:26 PM)
I've always wondered then, why do high-performance cars have them?

Lamborghini Murcielago
http://www.swisscarsightings.com/lamborghini/Lamborghini%20Murcielago%20340.jpg

Porsche 911 GT3
http://images.automotive.com/cob/factory_automotive/images/Features/auto_shows/2004_CIAS/2004_Porsche_911_GT3_wheels.jpg

2006 Corvette
http://www.canadiandriver.com/discus/messages/1490/24053.jpg

Enzo Ferrari
http://www-personal.engin.umich.edu/~dixitp/photos/autoshow03/P1180880.jpg

Unfortunately anti-rice is down so i can't get the link to the actual reason because we did one of these threads a while ago... But it was explained something like this....

The exotics use crossdrilled for astetics and less rotational mass.... Usually exotic setups have more braking capacity then is actually required for the vehicle.... So you can crossdrill the rotors to lighten the load and appeal to the eye without actually decreasing the max braking the car can do... (because the system itself far surpasses what the tires and the suspension will allow)

So short answer, it looks cool....

Posted by: Nd4SpdSe Sep 23 2005, 05:09 AM
Well, I've been runing Brembo Cross-Drilled and Slotted with PBR ULX Ceramic pads. I kept the Dot3 Fluid (cause I would need to change all the parts to make sure the system is clean) and want with new steel lines, although I wanted to get stainless steel/teflon braided lines, a miscommunication between me and the guy ordering the lines would have put them beyond my available timeframe, fortunately I found out that they are not DOT approved in Canada, so I don't feel do bad

Although I can&!39;t give a blank rotor vs XD/S rotor comparison because of the upgrades in pads, I will say that the combo I'm working with is amazing and hasn't decreased in the several months I've ran them. It's neat, me and a friend were driving about on the highway and were playing around, I was behind him and he saw a cop way up ahead and slammed on the brakes. Now, I don't slam on them cause I know they would lock up, but I was pretty hard on them and not only did it feel like my heart was going to come out of my chest, but it almost felt like my rear wheels wanted to come off the ground.

We did some touge "crusing" with the Rx-7 club in spring and they performed great, even when my rear wheels were 2" off the ground (literally, as the Rx-8 driver behind me witnessed). I can't wait until next year biggrin.gif

I did a tune up and I was checking the rotors, they are acually worn in about 1-2mm, so there's some good friction going on, and I can't see the XD/S rotors being anything but beneficial at this point. I know last time I went on the Rx-7 cruise, that my rotors literally burned blue from overheating, how, my car, although it didn't have as much power, it didn't handle as well either do I was doing more braking, but even this year, it wasn't a walk-in-the-park either, although I'm happy that I kept up with the Turbo FD's no problem biggrin.gif And they were really impressed as well. My setup was only a few days old at the time, but next year, I'll push her alot more, I'll show them what my Mx-3 truely can do biggrin.gif

Posted by: sideways Sep 23 2005, 06:36 AM
Braided lines often dont pass dot approval because they rarely pass the "spin" test (which has jack to do with braking anyways- so who gives a crap)

Posted by: Batmanbeyon Sep 28 2005, 10:55 PM
i recomend the SS lines they will make the pedal more stiff and under extreme preasure they wont blow unlike the fatory lines.

Posted by: BOZZ Savage Jul 21 2006, 11:07 PM
wow thanks for clearing that up... my dad and i actually had a discussion on this cross drilled slotted rotors thing and now i actually now the true answer...

sorry for reviving an old thread. sad.gif

Posted by: DALAZ_68 Aug 21 2006, 12:35 PM
stupid question but.....



is the surface of the disk increased (from say a 7 diamater to a 10 diameter ) becuase of the decrease in the surface due to the slotted/ crossdrilled ?!!?


in other words because u have gaps/ holes, u compensate by increasing the surface amount??!!?

i wonder if anyone understands my queston sweatingbullets.gif

Posted by: Frost Aug 21 2006, 05:40 PM
Well, mathematically if you drill holes into the surface, you lose that surface area. So when you increase the disc diameter and keep the hole density (holes per unit surface area) the same, you will increase the surface area.

Frost

Posted by: DALAZ_68 Aug 22 2006, 04:09 PM
QUOTE (Frost @ Yesterday at 6:40 PM)
Well, mathematically if you drill holes into the surface, you lose that surface area. So when you increase the disc diameter and keep the hole density (holes per unit surface area) the same, you will increase the surface area.

Frost

so... is that a yes to wut i said blink.gif lol

Posted by: BOZZ Savage Aug 26 2006, 02:00 PM
lol

Posted by: Batmanbeyon Aug 26 2006, 02:36 PM
that is a long first post all i have to say is that i seen the cracking happen before on corss drilled back when i was in cali doing the canyon thing some peoples brakes got so hot from going from no braking to full braking on and off and since it's not like at the track your on them a lot so a lot so that cooling and extreme heat was bad of people just have slotted.

Posted by: Rudy Sep 18 2006, 06:22 PM
QUOTE (DALAZ_68 @ Aug 22 2006, 09:09 PM)
so... is that a yes to wut i said blink.gif lol

Essentially, yes. Check out sport bikes with "pepperoni pizza" rotors as evidence.

Posted by: sideways Sep 19 2006, 12:40 AM
QUOTE (Batmanbeyon @ Aug 26 2006, 04:36 PM)
that is a long first post all i have to say is that i seen the cracking happen before on corss drilled back when i was in cali doing the canyon thing some peoples brakes got so hot from going from no braking to full braking on and off and since it's not like at the track your on them a lot so a lot so that cooling and extreme heat was bad of people just have slotted.

http://dictionary.reference.com/search?q=Punctuation

Posted by: sideways Sep 19 2006, 12:41 AM
QUOTE (Batmanbeyon @ Aug 26 2006, 04:36 PM)
that is a long first post all i have to say is that i seen the cracking happen before on corss drilled back when i was in cali doing the canyon thing some peoples brakes got so hot from going from no braking to full braking on and off  and since it's not like at the track your on them a lot so a lot so that cooling and extreme heat was bad of people just have slotted.

http://dictionary.reference.com/search?q=Punctuation

Posted by: HorizontalMitsubishi Sep 19 2006, 10:01 AM
THE DOUBLE POST, ITS SOOO ANGRY!!!

Posted by: sideways Sep 19 2006, 01:27 PM
user posted image

Posted by: TRD-hachi-roku Sep 23 2006, 01:07 PM
you want more good braking power? replace your old jankyass master cylinder, and brake booster, then get yourself some nice new blank rotors, sport/ street pads (if it is still a street driven vehicle), ss brake lines, good brake fluid, bleed the shit out of the system.

that way you will have refresh most of the components on your braking system, not only will you have better brakes, but safer ones too...what good is 3000$ big brake kits...when your master cylinder is leaking like a lil bit**?

Posted by: DALAZ_68 Oct 10 2006, 12:57 PM
QUOTE (Midnight Dorifuta @ Sep 18 2006, 07:22 PM)
Essentially, yes. Check out sport bikes with "pepperoni pizza" rotors as evidence.

blink.gif blink.gif i du get it ? blink.gif blink.gif

Posted by: Force Fed Mopar Oct 17 2006, 09:54 AM
So, what I've heard of cars w/ blanks out-braking the same cars w/ X-drilled rotors because the XD'd rotors wouldn't come up to temp enough could be true? or false? I agree that good pads and fluid make a much bigger difference than drilled rotors.

Posted by: sideways Oct 17 2006, 02:42 PM
Xd'ed rotors also have less surface area in contact with the pad

Posted by: Akira Jan 1 2007, 06:57 PM
So I imagien then, because according to physcis.., having cross drilled and slotted rotors just adds the effects? Sounds like amazing braking but maximum pad wear..
Not exactly what we all need...

Posted by: Inygknok Jun 13 2007, 10:08 PM
Okay, got sleepy half way through. Kudos to Nick for posting all that info (first time in my life I have seen that much info about brakes in one place, and I have seen a lot of info).


I'm sure everyone already understands the purpose of drilling brakes. Unsprung weight, but they crack, yadda yadda. EOS.


Now, slotted rotors. I don't know if someone mentioned this after I stopped reading, but here is a little factoid. The little slots act like a very fine knife cutting away the pads bit by bit. You can barely notice it, but it's true.


As for the brake fluid. ALWAYS study up on the fluid you want to use and NEVER mix it with old fluid. They all have different operating temps and quite a few of them get easily contaminated with humidity. Yes. Everytime you open up the cap, even if just to have a look, a little bit of humidity mixes with the fluid and it ruins it. As easy as it sounds, as easy as it gets ruined. Some are very well made and don't get spoiled that easily, but it still happens. Companies should have charts of how their products stand up to these conditions. Give them a call. And if the bastards won't say, Google is your friend.


As for pads glazing, it's generally due to their materials. Other times, the pads and discs themselves aren't up to the work of constant hard braking and glaze, and may even catch on fire (seen it in person, what a riot). This is why super cars usually opt for ceramics, and why F1 cars use carbon fiber.


Someone said that using smaller discs meant using smaller pads...... not completely true. You do need to use a pad that won't actually overshadow the disc, but doesn't always have to be the case. Some people get slightly larger discs while still using the stock caliper/pad. It really depends.


TRD-hachi-roku: Replace the brake booster? Do you know how much those cost? It is generally rare for one to actually break. Replacing parts that are still functioning properly is just throwing money into the garbage due to lack the ability to inspect things properly. No offense. Also, you forgot to mention obtaining brake calipers with more clamping force. Better pads and better/new discs help, but they won't work as well as some people would like to believe without opting for a stronger caliper wink2.gif

Only problem.... buying aftermarket calipers is one, f**king expensive ordeal..... so, people wanting to get stronger calipers, just use Google and try to see what better calipers from other cars can mount up to your current one with some mild mods grin2.gif

Posted by: SR5Sedan Jun 22 2007, 08:31 AM
Gimme a brake!

I'm cheap.

Rather than think about slotted vs. drilled, think about this:

1) Brake fluid is the most important part of a braking system. Change it and upgrade it, and make sure you bleed it properly, hammer it, and check it again.
2) A good tool is available from your local Radio Shack. It's an infrared thermometer. Point it at your left brake and right brake after a session of hard driving and the temps should be the same.
3) Your rim choice affects your brakes more than your rotor choice.
4) Both slotted and drilled rotors use more pads that a fat woman during her period.
5) For most reasonable (even race) circumstances of the time, smooth rotors only lose on a cold, wet, rainy course to the other two.
6) Proper brake bias is more important than slotted vs. drilled.
7) I know a fanboy who can prove w/a lot of finite element analysis that slotted+drilled is the "ultimate."

Posted by: Dakai Jun 22 2007, 08:46 AM
What about wave? It's a new type of rotor used on racebikes.

Posted by: SR5Sedan Jun 27 2007, 01:15 AM
I'll ask my bike mechanic about the wave thing.

It looks like it's good for show, or maybe on bikes, but my eyeballs scream that there's not enough material there to do the job.

Bike rotors get a lot more air than car rotors, so the wave thing might work on bikes. I'd be surprised if they ever show up on cars because of warpage and durability issues.

Posted by: But she looked 18 officer Jun 27 2007, 07:32 AM
http://www.corner-carvers.com/forums/showthread.php?t=2630&highlight=revolution+rotor
excerpt:
QUOTE (Jimmy Pribble)
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6386340.PN.&OS=PN/6386340&RS=PN/6386340

For teh lazy:

QUOTE
Quote:
United States Patent 6,386,340
Milesi , et al. May 14, 2002

--------------------------------------------------------------------------------
Motorcycle wheel brake mechanism


Abstract
A brake disc for a wheel constituted by a peripheral section, forming a brake band with an interior form enabling it to be fitted to its wheel, the brake band forms two lateral flat and parallel surfaces on which a brake shoe can act, said peripheral section having a series of off-sets on its inside and outside edges.


--------------------------------------------------------------------------------
Inventors: Milesi; Giorgio (Goleta, CA), Milesi; Umberto (Barcelona, ES), Milesi; Alfredo (Barcelona, ES)
Appl. No.: 09/490,042
Filed: January 24, 2000

--------------------------------------------------------------------------------

Current U.S. Class: 188/218XL ; 188/17; 188/264R
Current International Class: F16D 65/12 (20060101)
Field of Search: 188/17,18R,18A,26,218XL,264A,264R,264D D12/180



--------------------------------------------------------------------------------

References Cited [Referenced By]

--------------------------------------------------------------------------------

U.S. Patent Documents

2533480 December 1950 Leininger et al.
2850118 September 1958 Byers
2987143 June 1961 Culbertson et al.
3081842 March 1963 Zindler et al.
4848521 July 1989 Izumine
5358086 October 1994 Muller et al.
5850895 December 1998 Evrard
6164421 December 2000 Nakamura et al.


Foreign Patent Documents

WO 00/50109 Oct., 1999 WO

Primary Examiner: Oberleitner; Robert J.
Assistant Examiner: Williams; Thomas J.
Attorney, Agent or Firm: Arnhem; Erik M.

--------------------------------------------------------------------------------

Claims

--------------------------------------------------------------------------------


What is claimed is:

1. A motorcycle wheel brake mechanism comprising:

a brake disc attachable to a motorcycle wheel, and

a brake pad assembly carried by the motorcycle frame for frictional engagement with said brake disc;

said brake disc having two flat uninterrupted annular side surfaces, an inner edge connecting said flat side surfaces, an outer peripheral edge connecting said flat side surfaces, and mounting elements (2) extending from said inner edge for locating said brake disc in an exposed position on a motorcycle wheel;

said brake pad assembly comprising opposed brake pads (3) located along the rotational path of said brake disc for pressurized frictional contact with said flat side surfaces;

said brake disc having a rotational axis coincident with the wheel rotational axis;

the outer edge of said brake disc having an endless circular wave shape concentric around the disc rotational axis; said outer wave--shaped edge comprising recurring wave peaks and valleys spaced different radial distances from the disc rotational axis, said peaks being located on a first imaginary outer circumferential line centered on the disc rotational axis;

the inner edge of said brake disc having a circular wave shape concentric around the disc rotational axis,

said inner wave--shaped edge comprising recurring wave peaks and valleys spaced different radial distances from the disc rotational axis, the recurring valleys on said inner edge being located on a second imaginary circumferential line centered on the disc rotational axis;

each said brake pad having a radial dimension that is substantially the same as the radial spacing between the first and second imaginary circumferential lines, whereby the brake pads encompass the outer and inner edges of the brake disc.
--------------------------------------------------------------------------------

Description

--------------------------------------------------------------------------------


OBJECT OF THE INVENTION

As its title suggests, this invention refers to a brake disc for motorcycles or the like, with a series of constructional features on the peripheral part forming the brake band.

BACKGROUND TO THE INVENTION

Motorcycle brake discs generally have an external section which is ring-shaped, flat, and not very thick, on which the brake shoes operate; this external section forms the brake band. Said discs also have an interior form designed to allow them to be fixed on to the wheel. This interior form and the exterior section may be a monobloc unit or may be joined in such as way as to permit expansion of the outer section so that it will not become deformed when it heats.

One of the problems of such discs arises precisely from the heating they experience during braking so that, normally, the exterior part has a number of openings through it to facilitate cooling.

On so-called road motorcycles, the discs reach very high temperatures because of the speeds involved, so that the openings in the brake discs are important in facilitating cooling, should water get into these openings, it evaporates virtually instantly thanks to the high temperature of the disc.

However, on cross and trial motorcycles, these openings have advantages in terms of reduced weight, but they do have significant drawbacks when mud gets into them since it is unable to be released because the disc turns at a much slower speed than on road motorcycles.

A DESCRIPTION OF THE INVENTION

To overcome these problems, particularly on cross and trial motorcycles, the brake disc which is the subject of this invention has been designed with a number of constructional features on the peripheral section forming the brake band. These discs are preferably constructed by laser cutting, made from a high carbon stainless steel mixed material, based on 420 stainless steel materials.

In this invention, said peripheral part of the disc does not have inside holes, so that the problem of the accumulation and retention of mud inside them is overcome; said peripheral section also has a series of off-sets on its inside and outside edges of the same thickness as the rest of the section so as to reduce the total weight of the disc, facilitate its cooling and prevent mud from being retained inside.

Said off-sets on the inside and outside edges of the peripheral section of the disc are preferably arranged alternately so that the width of said section is substantially constant. As a result, during braking the contact surface of the brake band with the shoes hardly alters with the rotation of the disc; otherwise, braking may be intermittent and may vary according to the area of contact between disc and shoes.

To ensure uniform distribution of the disc mass, the inside and outside off-sets are distributed evenly on the periphery, in alternating form.

A DESCRIPTION OF THE DRAWINGS

To complete this description and aid in a better understanding of the features of the invention, these Specifications are accompanied by a set of drawings, forming an integral part hereof and where, by way of illustration and without limitation, the following is shown:

FIG. 1 is an elevated view of a variant of the design for the brake disk which is the subject of the invention, with the running band of sinusoidal form; this figure also shows the outline of one of the brake shoes, with a broken line.

FIG. 2 shows a design variant partially showing the peripheral section of the disc, in this case with substantially trapezoid-shaped off-sets.

A PREFERRED EMBODIMENT OF THE INVENTION

As can be seen from the aforementioned figure, the brake disc which is the subject of the invention comprises the usual peripheral section (1) forming the brake band, with an internal form (2) to enable it to be attached to its wheel.

As shown in FIG. 1, said peripheral portion (1) is a single solid block, with off-sets (11 and 12) on its inside and outside edges, distributed along those edges, and displaced at an angle to each other, so that the inside off-sets (11) are in the area between two consecutive outside off-sets (12); as a result, said peripheral section (1) is substantially the same width (d) throughout its length.

This constant width of the section (1) ensures that, during braking, the contact area between said section (1) and the brake shoes or pads (3) is constant; otherwise, braking might be intermittent, precisely because of the variations in the area of contact between the two elements.

The arrangement of the inside off-set (11) and their outside counterparts (12) not just helps to cool the disc, but also prevents mud or other elements which might negatively affect braking from accumulating on it.

As the figures show, the inside and outside off-sets (11 and 12) may be rounded, with section (1) taking on a sinusoidal form as in FIG. 1; or they may have different shapes as in the design variant in FIG. 2 where the off-sets (11a and 12a) are substantially trapezoid-shaped.

It will be noted that the inner and outer edges of brake disc 1 have endless circular wave shapes concentric around the disc rotational axis. Each wave--shaped edge comprises recurring wave peaks and valleys spaced different radial distances from the disc rotational axis. The peaks on the outer wave--shaped edge are located on a first imaginary circumferential line that passes across the outer edge of each brake pad 3. The valleys on the inner wave--shaped edge are located on the secondary imaginary circumferential line that passes across the inner edge of each brake pad 3. With the illustrated arrangement the brake pad encompasses the outer and inner edges of the brake disc, so that each side surface of the brake disc has maximum engagement with the associated brake pad. As previously noted, the wave--shaped inner and outer edges facilitate turbulent air cooling of the brake disc, without tending to accumulate mud debris on the friction surfaces.

It is not considered necessary to extend this description in order for any expert in the field to understand the scope of the invention and the advantages arising from it.

The terms of these Specifications must be taken always in the broad sense, without limitation.

The materials, shape, size and layout of the elements may be changed provided that this does not involve an alteration to the essential characteristics of the invention, claimed below.


I couldn't get the drawings to work.

Anyway, the easiest way to talk somebody out of these things, is to explain that they are gay. If that doesn't work, show them the patent, in which it is explained very clearly that these rotors are designed for "cross and trial motorcycles." If that doesn't scare them off...well, I'm not sure what can be done. I suppose you could start talking about thermal capacities and friction coefficients of SS vs. iron, but I get the feeling that somebody who wants "brake flowers" is going to get bored quickly with your technical mumbo jumbo.

I found a diagram of the Revolution brake rotor (similar to "wave") in a 1998 book called Braking Systems (Mike Mavrigian & Larry Carley). This is their comment:

QUOTE
"This super lightweight aluminum "Revolution" rotor from The Brake Man is a good example of how skeletonized a rotor can be and still perform. This style rotor can be used in some midget and sprint applications. Naturally, due to its light weight and minimal mass, this style of rotor is only suited to braking applications where braking demands are relatively light."

This is what http://www.thebrakeman.com/trotor_selection has to say about his own rotor:

QUOTE

Although the "REVOLUTION", has been specially designed and treated to take greater loads than would normally be capable by a steel rotor, it still is limited in where it should be used. If the "REVOLUTION", won't handle the track, then at that point, cast iron is more than likely your only choice.

By all accounts, it sounds like this style of rotor is for very specific applications only (cited: cross and trial motorcycles, midget and sprint cars). Outside of those specific applications, it is unlikely that these rotors are better than standard round rotors and could even be unsafe in some conditions.

Here, let's give the inventor a chance to sell his product. Okay http://www.galferusa.com/rotor411.html, bring the tech!

QUOTE

Why should you buy Galfer Wave Rotors:

• Cost less than OEM, OEM are not Wave.


OEM are not Wave? Does one of our Haiku experts want to step-in here?

QUOTE

• Used by many TOP race teams. Have the parts guy open any magazine.

Maj. Eaton: We have top men working on it now.
Indiana Jones: Who?
Maj. Eaton: TOP... men.

QUOTE

• Galfer advertises in a constant basis in magazines such as MXA, Dirt Bike, Transworld Magazine, Dirt Wheels, Cycle World or Road Racing World. We are out promoting our products.

rolleyes.gif

QUOTE
• Quality and longevity of the rotors, these are the “Ferrari” of the brake rotors.


And by Ferrari, we mean a Ferrari equipped with Brembo rotors.

So, we are to buy their rotors because they advertise in magazines? Is that the best tech we can get from the inventor of these things? BTW, it appears that the Wave and the Revolution were developed independantly, so there might be significant differences in their construction and applications (obviously, cars vs. bikes). I lumped them together, since they are both brake flowers. Check the specific manufacturers for information.


Cheers,

Jimmy


More tech:

http://www.wilwood.com/Products/002-Rotors/007-ULS/index.asp

QUOTE

Wilwood's ULD - 32 drilled and ULS - 32 scalloped iron rotors provide two highly effective lightweight options for sprints, late models, modifieds, and other competition applications that race in low to medium temperature ranges.


More support for this type of rotor only being used for specific, light-duty applications.

Posted by: Möbius Jun 27 2007, 07:38 AM
Time for me to google this "wave" technology. wink2.gif

Posted by: But she looked 18 officer Jun 27 2007, 08:40 AM
QUOTE (Manfred von Karma @ Today at 9:38 AM)
Time for me to google this "wave" technology. wink2.gif

be wary of fine print.

Posted by: Inygknok Jun 27 2007, 01:56 PM
QUOTE (Manfred von Karma @ Today at 7:38 AM)
Time for me to google this "wave" technology. wink2.gif

I think I'll tag along. I hadn't heard of this before. Then again, I'm not a bike guy.

Posted by: But she looked 18 officer Jun 27 2007, 04:25 PM
What no reply or thoughts on what I posted? tongue.gif

Posted by: MidnightViper88 Jun 27 2007, 08:20 PM
Some of us have ADD and can't even get past the patent numbers...

Posted by: Inygknok Jun 28 2007, 10:45 AM
QUOTE (MidnightViper88 @ Yesterday at 8:20 PM)
Some of us have ADD and can't even get past the patent numbers...

He pretty much summed it up.


I'll be honest, I just bothered reading a bit and saw the pictures..... in all honesty, those little waves will reduce contact area. People might think it's just a bit, but take into consideration the amount of contact area provided by an 11.5" rotor vs a BBK disc of about 13.5". The increase is massive. Those little "waves" seem to be a factor that just MIGHT reduce the extra surface area provided by the extra 2 inches of the bigger brake disc.


I can see the pros and cons just by looking at the design, but honestly, I believe the cons outweigh the pros on this.


For racing applications, modified discs have worked just fine up until today by using cross-drilling, vents (which are found in almost every modern car today), specials coatings, and using different materials.


For street applications, how many of you honestly drive so hard in the streets to cause the brakes to catch on fire? Before anyone gets clever, I am speaking realistically and legally. Race on the streets, and catch you brakes on fire, I'll laugh. But yeah, there's just no way to make the brake upgrade kits we can already buy overheat on the streets in a realistic scenario, unless you screwed up mounting them up and following protocol (brake fluid choice, materials, etc). Also, if you're using your weekend track car as a daily driver, here's what's done in your case: carry an extra set of brakes. 1 for every day, and swap it out at the track on the weekends.


So in summary:

CONS:
a) Sacrifices contact area to lose weight
cool.gif should cause uneven pad wear
c) Traps water wherever the hell it was that it got trapped, which is a horrible thing to happen, since those things need to maintain their shape to actually work. Warping on these things has to be fatal.
d) Might cause uneven pad wear
e) Probably more expensive to buy due to it's shape.
f) More expensive to maintain due to the latter.
g) and is probably cosmetically unappealing to the majority.

PROS:
a) Reduces weight by eliminating contact area
cool.gif Allegedly provides better cooling (I can actually imagine how it works, so I have no reason to doubt it, but I still question the method in terms of practicality).
c) Might be appealing to the minority (kids still like going against the majority, right?)

Posted by: But she looked 18 officer Jun 28 2007, 02:06 PM
QUOTE (MidnightViper88 @ Yesterday at 10:20 PM)
Some of us have ADD and can't even get past the patent numbers...

skip pass the patent part and he brakes it down and explains everything.



actually f**k it. I dont even know why I bother to post shit here anyway.

Posted by: MidnightViper88 Jun 28 2007, 02:13 PM
QUOTE (But she looked 18 officer @ Today at 5:06 PM)
skip pass the patent part and he brakes it down and explains everything.

Damn, I'm gonna have to remember that statement so I can use it as a pun...

Posted by: But she looked 18 officer Jun 28 2007, 02:40 PM
QUOTE (MidnightViper88 @ Today at 4:13 PM)
Damn, I'm gonna have to remember that statement so I can use it as a pun...

zing!



I meant to do it.. really whistling.gif

Posted by: SR5Sedan Jun 29 2007, 07:59 AM
Nice updates to the thread...

The "wave" thing looks to be good for getting mud out of your brakes. I thought of a good application though:

True: When you're riding dirt bikes with friends and "leading" and there's a pile of horse dung in front of you, it's a lot of fun to not dodge it. If you clutch, over-rev, and release perfectly, you will spray your pal behind you with manure.

It keeps them off of your line.

Sometimes the eyeballs are right.

The physics behind off-road two-wheel braking vs. on-road four-wheel braking are immense. Wave might work in muddy conditions (and might not even be worth it then), but not on cars.

Nice to see that braking is important to some folks though.


Posted by: snoro Jun 23 2008, 03:39 PM
braking will be alway important when you see a corner after going trough a straight at 150mph.

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