1. Jeff Seighman

    Jeff Seighman not my real name

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    Are drilled and slotted rotors worth it on the street? Do they decrease stopping distance? 1970 340 Dart. Thanks.
     
  2. Ironracer

    Ironracer Gearhead

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    The 07 Dakota I just picked up to replace my totalled Jeep (@&#^@^^%%!!!, as@^$&#%@/[??*&%%%@!!) Has em. When you put some foot in em, they grab. Normal it's fine, doing 75 and rolling up to a tool booth, no problem.
     
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    • dano

      dano Evil Handy Man

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      Due to advances is pad materials they are not really required or better than solid blanks. In fact they can crack where the holes are. One could argue slotted rotors help clean pads.

      The purpose of them originally was older pads would out gas, causing what they called "Green Braking". The gas build up diminished braking, so ports we're put to to allow the gas to escape. Slots were a away to to prevent cracking.
       
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      • Jeff Seighman

        Jeff Seighman not my real name

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        I have EBC red pads, ceramic on the stock rotors and the brakes work well, so no real improvement with the drilled and slotted? They are manual if that matters.
         
      • Dana67Dart

        Dana67Dart The parts you don't add don't cause you no trouble FABO Gold Member

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        Assuming you don't have a situation for Gases to buildup the holes and slots have removed some (all be it small) surface area. so all other things being equal you will have less braking ability.

        But this is really splitting hairs

        I too have heard of drilled VENTED rotors cracking due to the holes.
         
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        • Jeff Seighman

          Jeff Seighman not my real name

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          I think I'll just keep what I got and save some money.
           
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          • dano

            dano Evil Handy Man

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            I think unless you have a dedicated track car and are working the brakes hard, then it might be an option based on pad choices and limitations on rotor size. Good tires would be a good investment to increase braking.
             
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            • mvh

              mvh FABO Gold Member FABO Gold Member

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              The holes aid cooling after repeated hard stops. Not really needed for most street driving. I installed them after having heat issues in mountain driving (the automatic doesn't hold the speed down on hills very well). They do work extremely well on the track — on a track day at Willow Springs I had no issues despite maximum braking from 110mph on every lap. Another consideration was that the slotted cross drilled rotors I bought were American made. At the time is was very hard to get decent replacement rotors for the Kelsey-Hays brakes — there were many complaints about "Chinese junk". But what they won't do is reduce stopping distance — that is really down to the tires, assuming your brakes work at all (even 9" drums will lock up the wheels).
               
            • ir3333

              ir3333 Well-Known Member

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              Somewhere at the bottom of the heap there is a grain of relevance...but you'll probably never find it on the street.
              i'd put them in the purple air cleaner, purple oil, purple brake fluid,water wetter, air gap file.
               
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