drilled and slotted brake rotor? - Page 2 - JeepForum.com
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post #16 of 42 Old 07-24-2012, 09:59 AM
tjkj2002
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Originally Posted by IndyBlueWK View Post
dude please tell that to the engineers that get paid 6 figures a year at Mercedes Benz because drilled rotors come stock on the AMG's...
For looks.

Might want to look at NASCAR,Indy,and Formula 1,none use drilled rotors anymore.


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post #17 of 42 Old 07-24-2012, 10:05 AM
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post #18 of 42 Old 07-24-2012, 11:21 AM
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Quote:
Originally Posted by tjkj2002 View Post
For looks.

Might want to look at NASCAR,Indy,and Formula 1,none use drilled rotors anymore.
Your right they use carbon fiber rotors and you can’t make me believe that Mercedes Benz puts them on for looks and the Z06?? ... And let me guess every single motor cycle manufacture does it to just to look cool??
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post #19 of 42 Old 07-24-2012, 12:56 PM
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Originally Posted by IndyBlueWK View Post
Your right they use carbon fiber rotors and you can’t make me believe that Mercedes Benz puts them on for looks and the Z06?? ... And let me guess every single motor cycle manufacture does it to just to look cool??
Drilled rotors are old tech,used only today for aesthetic appeal.

Here is what Wilwood has to say about it...............
Quote:
PSlots 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. Also, cross-drilling 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 began to break down at extreme temperatures. This condition is often referred to as “outgassing.” When it does occur, the driver still has a good firm brake pedal, but a significant reduction in friction. Normally this only happens at temperatures witnessed in racing. However, with today’s race pad technology, “outgassing” is no longer a concern with pads designed for racing.

So in the final analysis, drilling and slotting rotors has become popular in street applications for their pure aesthetic value. Wilwood provides rotors slotted, drilled or plain. For most performance applications, slotted is the preferred choice. With certain pad material, slotting can help wipe away debris from between the pad and rotor as well as increasing the coefficient of friction between the rotor and the pad. A drilled rotor provides the same type of benefit, but is more susceptible to cracking under severe usage; however, for street and occasional light duty track use, they will work fine. For more severe applications, we recommend slotted rotors.

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post #20 of 42 Old 07-24-2012, 01:03 PM
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Ok I will bite...Wildwood agrees with my use of cross drilled rotors..."however, for street and occasional light duty track use, they will work fine."

My Stillen cross drilled rotors stop me just fine and they look way cool. Also the KJ forum is that way --------------->

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post #21 of 42 Old 07-24-2012, 01:06 PM
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Originally Posted by scootr29 View Post
Ok I will bite...Wildwood agrees with my use of cross drilled rotors..."however, for street and occasional light duty track use, they will work fine."

My Stillen cross drilled rotors stop me just fine and they look way cool. Also the KJ forum is that way --------------->
And brakes has what to do with what type of vehicle you drive? Nothing.


Have fun with drilled rotors but a quality set of blanks with the correct pads will out brake any drilled rotors on the street.

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post #22 of 42 Old 07-24-2012, 01:24 PM
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Quote:
Originally Posted by tjkj2002 View Post
Drilled rotors are old tech,used only today for aesthetic appeal.

Here is what Wilwood has to say about it...............
Weird does wilwoods come stock on any car? Not that I recall... Could be wrong no one's perfect...
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post #23 of 42 Old 07-24-2012, 02:03 PM
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Another bump for Stillens from Kolak, very happy with mine.

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post #24 of 42 Old 07-24-2012, 02:39 PM
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Originally Posted by tjkj2002 View Post
And brakes has what to do with what type of vehicle you drive? Nothing.


Have fun with drilled rotors but a quality set of blanks with the correct pads will out brake any drilled rotors on the street.
That is a broad statement.....that is like me saying a Grand Cherokee with a quality driver will out off road a Liberty......

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post #25 of 42 Old 07-24-2012, 02:46 PM
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Quote:
Originally Posted by IndyBlueWK View Post
Your right they use carbon fiber rotors and you can’t make me believe that Mercedes Benz puts them on for looks and the Z06?? ... And let me guess every single motor cycle manufacture does it to just to look cool??
Bikes run non vented rotors, basically old school then use the holes for cooling.

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post #26 of 42 Old 07-24-2012, 03:44 PM
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This is the Society of Automotive Engineers report summary for the record:

Conclusions:

1: Effect of Crossdrilling on Brake Cooling

90 hole crossdrill pattern on the front of system 1 improved heat rejection capability of the rotor between 8.8% and 20.1% depending on vehicle speed. A 64 hole crossdrill added to the rear improved heat rejection of the rear by 3.2% - 8.5%. This was confirmed in system 2 and improved heat rejection through the entire speed range of 50 kph to 140 kph.

These results are consistent with the theory that rotor crossdrilling can increase heat rejection capability of the brake rotor by improving airflow through the vent area of the rotor but it is possible to divert too much of the airflow through the vent area to the crossdrill holes than to the outer edge of the rotor, depending on rotor vane type.

2 and 3: Effect of Crossdrilling on Brake Output and Wet Braking

Both systems 1 and 2 exhibited higher brake system output in high temperature, high brake pressure conditions with crossdrilled rotors than with non-crossdrilled rotors. System 3 employed NAO (non-asbestos organic) pads and did not benefit from crossdrilling.

This supports the theory that crossdrilling provides macroscopic mechanical interface between the pad and rotor to improve braking and resist brake fade.

4: Effect of Crossdrilling on High Temperature Pedal Feel

High speed fade testing resulted in lower pedal travel to a target vehicle deceleration with crossdrilled rotors. Less apply system runout was noted with the crossdrilled rotor configurations. This was due to brake system output with the crossdrilled rotors being high enough versus output with the non-crossdrilled rotors to reduce operating pressure. Less taxing on the master cylinder and vacuum brake booster on the apply.

5: Effect of crossdrilling on lining wear

Depending on configuration of the brake system, there can be little difference in lining wear but the largest difference occurs and higher temperatures where the lining softens and can be extruded into the crossdrilling holes. High temperature conditions also proved to wear linings faster on the non-crossdrilled rotors.

6: Other effects

Whirring noise under certain conditions. Risk of crevice corrosion. Holes can collect wear and road debris. Possible reduction of rotor fatigue life. Reduced risk of pad friction surface glazing and reduced judder mechanisms.
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post #27 of 42 Old 07-24-2012, 04:25 PM
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Quote:
Originally Posted by Kolak View Post
This is the Society of Automotive Engineers report summary for the record:

Conclusions:

1: Effect of Crossdrilling on Brake Cooling

90 hole crossdrill pattern on the front of system 1 improved heat rejection capability of the rotor between 8.8% and 20.1% depending on vehicle speed. A 64 hole crossdrill added to the rear improved heat rejection of the rear by 3.2% - 8.5%. This was confirmed in system 2 and improved heat rejection through the entire speed range of 50 kph to 140 kph.

These results are consistent with the theory that rotor crossdrilling can increase heat rejection capability of the brake rotor by improving airflow through the vent area of the rotor but it is possible to divert too much of the airflow through the vent area to the crossdrill holes than to the outer edge of the rotor, depending on rotor vane type.

2 and 3: Effect of Crossdrilling on Brake Output and Wet Braking

Both systems 1 and 2 exhibited higher brake system output in high temperature, high brake pressure conditions with crossdrilled rotors than with non-crossdrilled rotors. System 3 employed NAO (non-asbestos organic) pads and did not benefit from crossdrilling.

This supports the theory that crossdrilling provides macroscopic mechanical interface between the pad and rotor to improve braking and resist brake fade.

4: Effect of Crossdrilling on High Temperature Pedal Feel

High speed fade testing resulted in lower pedal travel to a target vehicle deceleration with crossdrilled rotors. Less apply system runout was noted with the crossdrilled rotor configurations. This was due to brake system output with the crossdrilled rotors being high enough versus output with the non-crossdrilled rotors to reduce operating pressure. Less taxing on the master cylinder and vacuum brake booster on the apply.

5: Effect of crossdrilling on lining wear

Depending on configuration of the brake system, there can be little difference in lining wear but the largest difference occurs and higher temperatures where the lining softens and can be extruded into the crossdrilling holes. High temperature conditions also proved to wear linings faster on the non-crossdrilled rotors.

6: Other effects

Whirring noise under certain conditions. Risk of crevice corrosion. Holes can collect wear and road debris. Possible reduction of rotor fatigue life. Reduced risk of pad friction surface glazing and reduced judder mechanisms.
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Must be a very old article as what is in bold say's all since pads containing asbestos have not been produced for a very long time.New pads do not experiance "outgassing" so no need for any escape path for something that no longer occurs.

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post #28 of 42 Old 07-24-2012, 05:10 PM
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The study was just done a few years ago. "System 3" was done with older style pads as part of the experiment.

Quote:
Originally Posted by tjkj2002 View Post
Must be a very old article as what is in bold say's all since pads containing asbestos have not been produced for a very long time.New pads do not experiance "outgassing" so no need for any escape path for something that no longer occurs.

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post #29 of 42 Old 07-24-2012, 05:23 PM
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Quote:
Originally Posted by terrasmak View Post
Drilled rotors are a joke, they are well outdated to today's standards
That is correct ... especially for a Jeep or offroad vehicle.

Slotted or the wave slot is the way to go. The drill pattern does NOT release the gasses as quickly as the slot and just tears into the pads.

Look at any of the high end race truck brakes being used. They are all slotted, not drilled.

If you want to constantly shave off your brake pads and look cool then drilled is the way to go, but for performance slotted is better.
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post #30 of 42 Old 07-24-2012, 06:45 PM
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Originally Posted by Kolak View Post
The study was just done a few years ago. "System 3" was done with older style pads as part of the experiment.
Older style pads have asbesto's that are prone to outgassing,it's the new style pads that do not so that artical could not be a few years old.It would have to be 20+ years old,if not 30+ years old due to asbesto's in brakes have been long gone which are the only pads that would see any benifit from drilled rotors.

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