Need help explain slotted/drilled rotors...
05-25-2006, 12:26 PM
#41
I don't get it.... zinc is just a rust thing, and it's not a guarantee, just an inhibitor. I could care less if my rotor hats are rusty.
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
05-25-2006, 10:14 PM
#42
TECH Enthusiast
iTrader: (5)
Join Date: Mar 2004
Location: New Orleans, LA
Posts: 556
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Dom
I like how all the drilled/slotted threads explode with all the experts, but when I made a thread about a good blank, no responses.
https://ls1tech.com/forums/suspension-brakes/506137-need-zinc-coated-rotors.html
https://ls1tech.com/forums/suspension-brakes/506137-need-zinc-coated-rotors.html
And, Sam, you know that deep down inside you lose sleep over those rusty hats! I've seen you scrubbing them with Brillo pads between runs!!
FWIW, here are the rotors that I run on my high-speed track days:
05-26-2006, 07:32 AM
#43
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 00 Trans Ram
Perhaps that's because the worst case scenario with a zinc rotor question is you get a little rust on the unused portion. But, with a drilled/slotted rotor, the worst case scenario is that your DNA becomes forcibly inserted into the atomic structure of the brake rotor. Maybe they're trying to save lives.
And, Sam, you know that deep down inside you lose sleep over those rusty hats! I've seen you scrubbing them with Brillo pads between runs!!
FWIW, here are the rotors that I run on my high-speed track days:
And, Sam, you know that deep down inside you lose sleep over those rusty hats! I've seen you scrubbing them with Brillo pads between runs!!
FWIW, here are the rotors that I run on my high-speed track days:
It was you that stole that medallion off the S&M store on the corner just to modify your brakes. Be an honest guy and return to it to their rightful owners (you really should despite the embarrassment)
05-26-2006, 04:19 PM
#44
TECH Fanatic
Originally Posted by Dom
I just saw the brakes on a CarreraGT and Turbo911. Both are drilled. I guess it's not that big of a deal since those are pretty top notch performing cars. And I doubt the guys who designed those cars are idiots.
05-26-2006, 04:58 PM
#45
Originally Posted by chicane
No. They are not drilled.... they are cast in. Big difference when dealing with crystaline grain structure and strees riser issues.
http://corner-carvers.com/forums/sho...rilled+porsche
Several very bright minds have not been able to prove it. But I'm interested in seeing it go one way or the other.
I'm not trying to start a fight, but we've been trying to prove or disprove that as fact and have not been able to substantiate the cast holes information. It's starting to look like they are drilled as well (at this time).
Edit to fix typo.
Last edited by trackbird; 05-27-2006 at 11:58 AM.
05-26-2006, 06:08 PM
#46
TECH Enthusiast
iTrader: (5)
Join Date: Mar 2004
Location: New Orleans, LA
Posts: 556
Likes: 0
Received 0 Likes
on
0 Posts
Well, I just posted my $200 answer on Corner-Carvers. Here it is:
However, for the purposes of this discussion, I see nothing that mentiones they are drilled for "outgassing" - just heat and moisture. Also, not being a metalurgist, I don't know if the properties of carbon brakes are compromised by drilling like iron.
Well, I'm no rocket scientist, but you can send my $200 to me anyway. Read the Porsche website at http://www.porsche.com/usa/models/ca...brakingsystem/
See where, in the second paragraph, it says, "cross-drilled"? That means they are drilled, not cast.
PM me for my address.
(j/k - no payment required)
Porsche Leipzig GmbH Porsche Sportfahrschule Motorsports The braking system features one of the latest advances in Porsche race engineering: the Porsche Ceramic Composite Brake (PCCB). This remarkable technology consists of a lightweight ceramic disc with involute cooling channels and a specially developed composite pad. Each of the front and rear discs has an impressive diameter of 14.96 inches (380-mm).
Cross-drilled and internally vented for optimum dispersal of moisture and heat, the finished PCCB disc offers an approximate 50% weight saving over conventional metal equivalents. Since all of that weight is entirely 'unsprung' – i.e., not supported by the car's suspension – the PCCB system delivers immediate benefits in terms of handling, agility and fuel economy.
Each disc is gripped by a powerful six-piston caliper with specially formulated composite pads.
The resulting brake action provides breathtaking deceleration as well as unparalleled consistency and consistently high friction levels across a wide range of operating temperatures. Thanks to its enhanced stability in all conditions, PCCB helps minimize braking distances in even the most extreme road and track scenarios.
Inherent fade resistance makes for safer deceleration from even the highest speeds, while the system's prodigious response requires only moderate pedal inputs from the driver.
Another key benefit of the PCCB system is the remarkable durability of both pads and discs. While the actual rate of wear on all brake components – particularly pads and discs – is entirely dependent on individual driving style and, of course, vehicle usage, like-for-like testing reveals a much longer lifespan compared with conventional systems.
With its major weight savings and exceptional fade resistance, even at very high temperatures, PCCB is the ideal option for genuine competition use. It is important to note, however, that circuit racing or similar extreme driving conditions can significantly reduce the overall life expectancy of even the most durable pads and discs. It is therefore important – as with conventional steel high-performance brakes – to have all PCCB components properly checked and replaced, if necessary, after every track event.
Cross-drilled and internally vented for optimum dispersal of moisture and heat, the finished PCCB disc offers an approximate 50% weight saving over conventional metal equivalents. Since all of that weight is entirely 'unsprung' – i.e., not supported by the car's suspension – the PCCB system delivers immediate benefits in terms of handling, agility and fuel economy.
Each disc is gripped by a powerful six-piston caliper with specially formulated composite pads.
The resulting brake action provides breathtaking deceleration as well as unparalleled consistency and consistently high friction levels across a wide range of operating temperatures. Thanks to its enhanced stability in all conditions, PCCB helps minimize braking distances in even the most extreme road and track scenarios.
Inherent fade resistance makes for safer deceleration from even the highest speeds, while the system's prodigious response requires only moderate pedal inputs from the driver.
Another key benefit of the PCCB system is the remarkable durability of both pads and discs. While the actual rate of wear on all brake components – particularly pads and discs – is entirely dependent on individual driving style and, of course, vehicle usage, like-for-like testing reveals a much longer lifespan compared with conventional systems.
With its major weight savings and exceptional fade resistance, even at very high temperatures, PCCB is the ideal option for genuine competition use. It is important to note, however, that circuit racing or similar extreme driving conditions can significantly reduce the overall life expectancy of even the most durable pads and discs. It is therefore important – as with conventional steel high-performance brakes – to have all PCCB components properly checked and replaced, if necessary, after every track event.
PM me for my address.
(j/k - no payment required)
05-27-2006, 12:35 AM
#48
TECH Fanatic
Well actually........ the 'cast in' information was obtained from a CC thread on the subject of drilled and/or slotted rotors. If anyone remembers the 64 page Altimas.net thread, you just might remember who stated just that.....as it was CC members handing *** to the unfortunate import experts.
And no.... Kevin is correct, the PCCB system isnt the same cookie we are discussing. I havent followed CC threads in a while, so I wasnt aware of the newer scuttle on this topic.
Roys postings do add to the equation though. There is material cast into MOVIT rotor for thru drilling that would reduce TBF.
Not to mention the comments and pictures from 914six back up the 'cast in' Porsche speak.
It looks like the rumor mill concerning the cast hole theroy is still in question.
And no.... Kevin is correct, the PCCB system isnt the same cookie we are discussing. I havent followed CC threads in a while, so I wasnt aware of the newer scuttle on this topic.
Roys postings do add to the equation though. There is material cast into MOVIT rotor for thru drilling that would reduce TBF.
Not to mention the comments and pictures from 914six back up the 'cast in' Porsche speak.
It looks like the rumor mill concerning the cast hole theroy is still in question.
Last edited by chicane; 05-27-2006 at 01:25 AM.
05-27-2006, 12:01 PM
#49
Originally Posted by chicane
It looks like the rumor mill concerning the cast hole theroy is still in question.
05-27-2006, 01:47 PM
#50
Staging Lane
iTrader: (1)
Join Date: Dec 2004
Location: Friedberg, Germany
Posts: 76
Likes: 0
Received 0 Likes
on
0 Posts
If Movit says the holes are cast made, I tend to beleive it, because they are known for quality here in germany and they only make brake systems (as far as I can see...).
If they would be proofed as liars, they could close their doors forever...
I've done a little research and all I could find until now... Porsche and Movit get their rotors from the same supplier...
Besides the statement of Movit on their Homepage, I could find a lot of postings in german car-forums, where they say that the holes in Porsche-rotors are cast made, but I couldn't find even ONE official statement from Porsche...
But thursday was an official holiday here in Germany, so it was difficult to get anyone at the phone...
Have you ever send this question to Porsche...? If not... why not?
If you contact a Porsche official, you should better not mention the name "Movit", or they...
Holger
If they would be proofed as liars, they could close their doors forever...
I've done a little research and all I could find until now... Porsche and Movit get their rotors from the same supplier...
Besides the statement of Movit on their Homepage, I could find a lot of postings in german car-forums, where they say that the holes in Porsche-rotors are cast made, but I couldn't find even ONE official statement from Porsche...
But thursday was an official holiday here in Germany, so it was difficult to get anyone at the phone...
Have you ever send this question to Porsche...? If not... why not?
If you contact a Porsche official, you should better not mention the name "Movit", or they...
Holger
05-27-2006, 04:11 PM
#51
TECH Fanatic
I believe that the statement of "Cast In".... possibly elludes to the casting mold itself that has the extra material for thru drilling. From there.... the story changes fifth or sixth hand and the next thing you know, the holes are actually cast thru the friction surface at the time of manufacture, people talk about Alien's and we just screwed the neighbor's cat.
I am fairly certain that there is no rotor with 'cast in thru' hole's at the time of manufacture.
Yes the holes are "cast made"..... but I think that they are still finished drilled.
I am fairly certain that there is no rotor with 'cast in thru' hole's at the time of manufacture.
Yes the holes are "cast made"..... but I think that they are still finished drilled.
05-27-2006, 04:38 PM
#52
TECH Fanatic
iTrader: (1)
Join Date: Sep 2002
Location: Brisbane, QLD, AUS
Posts: 1,747
Likes: 0
Received 0 Likes
on
0 Posts
I'm with Holger on this one in order to confirm or deny the rumour.
But for a brake application AFA the physics are concerned, I'd like to restate the exhausted questions:
Why try to engineer the direct usable friction path to have less friction in order to achieve cooling, when in fact the included ventilation design itself does a much better job with it (not including "motorcycle" rotors here). The ventilation path doesn't have to bear the burden of rotor surface to pad friction, and is much designed like a heat sink should be and works very well when properly ventilated with brake ducting. AFA outgassing, it definitely makes sense since the pad outgas needs to find the quickest way to escape from the pads, where ventilation is hard to fulfill, but again, how many pads today result in that phenomenon after a proper bed in (I can only think of one, and it's really not necessary for many applications, even the roughest motorsports).
Another question is with the rotors well enclosed within the wheels, and using no brake ducts, how easily can the air needed to properly dissipate heat from the rotor be easily accomplised? Between the rotor surface and the pads, the caliper and the fact the holes are on the friction faces and not on the sides where the vents are, how could air be easily and consistently be vented through them?
With the above concerns the vents seem to be a compeletely logical design with that concern. Direct ducting to the rotor face in general doesn't seem very efficient compared to ducting to the internal vanes.
For the concerns of better brake performance on most of the cars here, why has the rotor been overly emphsasised and the pads needed being underestimated? If the pads thickness and compound are designed to properly work within a specific temperature range and the rotor has enough overall mass, diameter, and friction surface area to bear with properly suited pad compound with the appropriate situation, then there seems to be not much else needed to do with the rotor.
But for a brake application AFA the physics are concerned, I'd like to restate the exhausted questions:
Why try to engineer the direct usable friction path to have less friction in order to achieve cooling, when in fact the included ventilation design itself does a much better job with it (not including "motorcycle" rotors here). The ventilation path doesn't have to bear the burden of rotor surface to pad friction, and is much designed like a heat sink should be and works very well when properly ventilated with brake ducting. AFA outgassing, it definitely makes sense since the pad outgas needs to find the quickest way to escape from the pads, where ventilation is hard to fulfill, but again, how many pads today result in that phenomenon after a proper bed in (I can only think of one, and it's really not necessary for many applications, even the roughest motorsports).
Another question is with the rotors well enclosed within the wheels, and using no brake ducts, how easily can the air needed to properly dissipate heat from the rotor be easily accomplised? Between the rotor surface and the pads, the caliper and the fact the holes are on the friction faces and not on the sides where the vents are, how could air be easily and consistently be vented through them?
With the above concerns the vents seem to be a compeletely logical design with that concern. Direct ducting to the rotor face in general doesn't seem very efficient compared to ducting to the internal vanes.
For the concerns of better brake performance on most of the cars here, why has the rotor been overly emphsasised and the pads needed being underestimated? If the pads thickness and compound are designed to properly work within a specific temperature range and the rotor has enough overall mass, diameter, and friction surface area to bear with properly suited pad compound with the appropriate situation, then there seems to be not much else needed to do with the rotor.
