Slotted Rotors

Discussion in 'Fox 5.0 Mustang Tech' started by smkshw, Mar 11, 2014.


  1. smkshw

    smkshw Active Member

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    i still have 4 lug and i ordered the maximum motorsports upgrade kit....just wondering if anyone has slotted rotors?....is it worth it to get them also?
  2. cdurbin

    cdurbin Active Member

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    I installed slotted/cross drilled on my 91 vert. I don't really think there is much of an advantage if any though. I just like the way they look.
    IMG_0182.JPG
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  3. smkshw

    smkshw Active Member

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    thats what i wanted to hear....makes me feel better cause i didn't order them.....looks awesome though....!
  4. 7upstang91

    7upstang91 Active Member

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    The slotted and drilled rotors have to do with cooling features and greater grabbing surface. More than likely (I don't know you or what you are doing with your car) you many never need drilled and slotted rotors, an upgraded rotor and pad combination will work great. That being said, I put drilled and slotted rotors on my step mom's G8, one it was time for new brakes, two they complement her wheels nicely because we liked the looks of the rotors.
  5. mikestang63

    mikestang63 Mustang Master

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    For most people you will never need them . I'd say for most guys, it's form over function- looks cool.

    Whatever you do, do not buy the cheapo Ebay ones. They crack due to inferior tolerances and not having enough surface material on them to hande the heat. In addition, good luck getting someone to turn those drilled and slotted rotors when they wear down or warp- again surface material loss , it tears up the rotor, and no one wants to do it. I've used the MM brake upgrade kit with SS hoses, caliper sleeves an Hawk pads on a few cars with stock style rotors and have been quite pleased.

    Holes really do little to nothing. Slots help dissipate gases. If you want to go that route, Stop Tech and/or EBC make a quality rotor but expect to pay for it.

    Also, do not do what some morons do- drill holes in your existing rotors.
  6. madspeed

    madspeed Colonel Mustard Mod Dude Founding Member

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  7. smkshw

    smkshw Active Member

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    ya i got the mm kit and lines with hawk pads,i have the 4 lug saleen replicas and im happy with them,just wanted a quick brake upgrade....anything should be better than stock,just didnt want to hear that they dont work as good without slotted rotors or something....thanks for the input...
  8. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    Ah, but that's not what they are for.

    The slots help to "wipe" the rotor/pad contact are of brake dust, water, debris etc. to provide a clean contact area. The slots basically give such material a location to "dump" into.

    The drilled holes pay homage to race-type brakes which use pads that off-gas under hard use. Such pads typically are not used on street cars. This is why $10K Porsche 911 brakes have cross-drilled holes, while putting holes in a modern street car is just for looks only. Comparing high-dollar exotic race brakes costing $10K or so, to $50 drilled rotors with street pads is not the same thing. Plus the "correct" drilled brakes are cast with the hols in them which help to releive stresses. Most aftermarket rotors are drilled after the fact.

    Brakes use their mass to help distribute heat. When you remove mass (by drilling or slotting), you concentrate the heat in the remaining mass of the rotor. This causes a higher brake rotor temp without the extra material to absorb it. Most hard-core racers use plain-jane blank rotors for racing as they have the bigger mass. Stotted rotors do have their benefit as well, but for the most part drilled rotors are for looks. On a typical weekend-cruiser type of street cars...you won't notice a difference at all if your rotors have slots or holes or nothing at all
  9. Grabbin' Asphalt

    Grabbin' Asphalt Mustang Master

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    I would think the slots would also act like a fan with air moving through the channel to help the cooling of the pad as it passes over each valley IMO.
  10. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    I would venture to say the impact of the slots on cooling would be minimal at the very most. Not enough volumn IMHO to make a significant impact. Having solid material in contact with the pad to absorb the heat would have a better impact than minor airflow
  11. Grabbin' Asphalt

    Grabbin' Asphalt Mustang Master

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    We need a slotted brake dyno :rlaugh:
  12. Grabbin' Asphalt

    Grabbin' Asphalt Mustang Master

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  13. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    I have read that report, and it actually leaves me with questions that I wish i could ask those engineers.

    But regardless, comparing high end rotors to ebay rotors is not the same thing. The manufacturing process is not the same. Rotors must be cast with the holes in them, and the vast majority of aftermarket rotors (especially cheap ebay ones) are drilled after the casting process. That's why I aluded to the fact that comparing the brake systems on high end cars is not the same as tossing a set of cross-drilled rotors on a Honda civic.

    I really wish i worked for Baer/Brembo :)
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  14. Grabbin' Asphalt

    Grabbin' Asphalt Mustang Master

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    Oh definitely wouldn't go ebay rotor route I just was I intrigued by the report stuff, ...Baer/Brembo would be awesome!!!
  15. Mustang5L5

    Mustang5L5 Car used in adult film "Highway Gangbang-InDaButt" SN Certified Technician Founding Member

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    What the ebay ad didn't mention in depth was that a lot of the improvements the GM engineers found were at high speeds....over 120MPH. At lower speeds under 100MPH, there really wasn't much of a difference in performance.

    I'd have to go back and find the original report as I'm going off memory.
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  16. smkshw

    smkshw Active Member

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    ya i wouldnt have went ebay...saw some on the latemodelrestoration site....who knows if there the same but was thinking those....some good info you guys posted up though....aswered any questions i had....
  17. 7upstang91

    7upstang91 Active Member

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    Mike,
    Yes, the direction where I was going with my vague post about the "greater grabbing surface" was referring to the slots, having to do with cleaning the surface for a better grab.

    Drilled you would be correct, for some reason I was thinking "cooling effects". But after I went and looked up the website we purchased from I remembered why we went with the drilled( How I justified the added cost in my head.)

    http://marylandspeed.com/build-your...-gt-g8dbahawk-p-2994.html?manufacturers_id=85

    But anyways, Mike you are correct. Didn't want to get into detail over my first post, but maybe should have. We went with the drilled and slotted rotors not only for increased stopping power but for the "look."

    Tyler
  18. mikestang63

    mikestang63 Mustang Master

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    Like I said earlier, wait until you need to get those cool looking drilled and slotted rotors turned.
  19. 7upstang91

    7upstang91 Active Member

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    The car will be long gone by then.
  20. mikestang63

    mikestang63 Mustang Master

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    those look like Power Stop rotors? About 50-70 each depending where you buy them. I think they are Centric blanks that are machined by Power Stop.

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