I know I'm going to be waxed for asking this but.....

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  • Alistair C
    S2Forum Maniac
    • Jul 2003
    • 693

    #16
    Originally posted by NoNonsense
    with the rear 996's, it's not about how much fluid is required to move, but it's about pad surface area
    I'm sure someone will correct me if I'm wrong, but the size of the internal cavities is critical when doing brake swaps.
    Using a stock system, when you push on the brakes, a certain amount of fluid will be sent to the front and rear calipers, the ratio being determined by the bias valve.

    If you change your front calipers for ones with much smaller internal cavities, in effect thsi will make the calipers bite much too early and way before the rears even come into play.

    I'm sure those calipers would give all the braking force required, but I'd just be wary of the whole brake bias issue.

    As I say - could be wrong - or blowing this whole issue out of proportion.
    I do know of people with corrados (which use single pot calipers) - changing over to 4 pot Brembos without any issue.

    Can anyone throw any experience or physics on the subject ??

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    • NoNonsense
      Forum Sponsor
      • Apr 2004
      • 673
      • Home: Italy Current: United States

      #17
      Well, you are probably correct, but I know someone who has Boxster front calipers on his 90 and his car brakes just as well as mine with the 996 calipers. For what it's worth, the 996 rear is a smiggin' bigger than the boxster fronts.
      Joe "NoNonsense"
      axis motorsport
      joe@axismotorsport.com

      "At the end of the game, the king and the pawn go back in the same box."

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      • Alistair C
        S2Forum Maniac
        • Jul 2003
        • 693

        #18
        Originally posted by NoNonsense
        Well, you are probably correct, but I know someone who has Boxster front calipers on his 90 and his car brakes just as well as mine with the 996 calipers. For what it's worth, the 996 rear is a smiggin' bigger than the boxster fronts.

        Castings might be a bit bigger on the 996 calipers, but according to the Porsche parts catalogue I've got here,

        996 fronts have 36 & 40 mm pistons
        996 rears have 28 & 30 mm pistons

        986 (std boxster) fronts have 36 & 40 mm pistons
        986 rears have 28 & 30 mm pistons

        Same piston sizes - just designed for different disk diameters and thicknesses.
        Would explain why your mate with his 986 front calipers is having no problems..... ?

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        • NoNonsense
          Forum Sponsor
          • Apr 2004
          • 673
          • Home: Italy Current: United States

          #19
          any ideas on pad surface areas??
          Joe "NoNonsense"
          axis motorsport
          joe@axismotorsport.com

          "At the end of the game, the king and the pawn go back in the same box."

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          • Alistair C
            S2Forum Maniac
            • Jul 2003
            • 693

            #20
            Originally posted by NoNonsense
            any ideas on pad surface areas??
            http://www.ebcbrakesdirect.com/image...ds/DP21207.jpg
            boxster front

            http://www.ebcbrakesdirect.com/image...ds/DP21208.jpg
            boxster rear

            http://www.ebcbrakesdirect.com/image...ds/DP21278.jpg
            996 front

            http://www.ebcbrakesdirect.com/image...ds/DP21208.jpg
            996 rear

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            • kwlw
              S2Forum Extremist
              • Sep 2004
              • 1025
              • Country: Lithuania

              #21
              2Panzerwagen - what is further progress of the idea to put porsche 996 rear calipers to the front of the coupe ?

              I'm asking because, I've got proposal to get 996 GT3 rear calipers for nice price.

              Sau
              200 20vt 88' 3b, human carrier
              CQ typ85 with AAN inside, see project blog at http://kwlw.blogspot.com

              Comment

              • 90quattrocoupe
                S2Forum Maniac
                • Nov 2003
                • 771
                • Country: United States

                #22
                Originally posted by kwlw
                2Panzerwagen - what is further progress of the idea to put porsche 996 rear calipers to the front of the coupe ?

                I'm asking because, I've got proposal to get 996 GT3 rear calipers for nice price.

                Sau
                If not mistaken, GT3 rears are the same calipers as the 996 fronts.

                Greg
                They can have my car when they pry my cold dead fingers from the steering wheel.

                Comment

                • Alistair C
                  S2Forum Maniac
                  • Jul 2003
                  • 693

                  #23
                  With regard greg's comment above - it was also my understanding that GT3 rear calipers are the same as Carrera / Boxster S fronts.

                  However, according to my Porsche parts catalogue (2000), the GT3 rear caliper has small pistons (28 & 30mm) - just like rears on the Carrera / Boxster S cars.

                  It is however possible that more recent GT3s share Carrera / Boxster S fronts.

                  Sorry if this doesn't clear anything up!
                  Last edited by Alistair C; 2 March 2005, 16:30.

                  Comment

                  • kwlw
                    S2Forum Extremist
                    • Sep 2004
                    • 1025
                    • Country: Lithuania

                    #24
                    Originally posted by 90quattrocoupe
                    If not mistaken, GT3 rears are the same calipers as the 996 fronts.
                    Greg
                    I think that you can be mistaken. It's hard to believe, that car uses same calipers in front and in the rear.

                    From the forum I can see, that according to the part number these are "simple" 996 rear calipers :/. Of course it could be that "gt3" just had a badge on the back and was a wrecked boxter . I'm not familiar with porsche models and this 996 doesn't mean something to me .

                    But google says, that 996 352 426 and 996 352 425 calipers are rear calipers from some porsche turbo.

                    Sau
                    200 20vt 88' 3b, human carrier
                    CQ typ85 with AAN inside, see project blog at http://kwlw.blogspot.com

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