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DefSport 12.2" Brake GB! Round 5 - 2015!!!

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  • Originally posted by Joe D View Post
    I might be interested as I've been thinking about making my own kit. According to my maths (which could be wrong), even though you have a 12% increase in rear piston area it only moves the brake bias 2% to the rear. That doesn't take in to account the pressure drop due to the stock proportioning valve though.

    I like the radial caliper mount setup. Is the bracket steel or aluminum?
    Yea, I think you're right. ~11.8% large piston area, not bias. My spreadsheet is showing 2% as well. Going to a 12.76" front rotor cuts the difference in half.

    The bracket is aluminum alloy 2024-T351, just like the Defsport lug mount brackets. Dimensionally, they locate the caliper on the rotor perfectly. I'm going to make a couple of adjustments for larger safety factor as per FEA and will be CNC'ing some more in a month or so. Def's concept was to be able to use them for a 11.75" rotor and then a 12.2" rotor with a spacer. I want to up that to 12.2 and 12.76 with a spacer. The brackets I pictured have no spacers.

    I'd be happy to make some for people on here so let me know if you're interested.

    As for piecing together a rear kit, I want to keep it simple. Probably use the lug mount calipers since they're cheaper than the radial mounts, but the radial mounts are a newer, better design. Good to know you may be interested though.
    Last edited by gills; 06-03-2017, 10:02 PM.
    Core4 Motorsports
    CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
    S14 VQ AER Endurance Racing Team

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    • Color me interested in a rear kit as well.

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      • Originally posted by gills View Post
        Ah, yea I always forget that you have a balance bar setup. Are you still racing the S14? What diff is in your car? You can run R-compound/slicks? If so, and I think you sprint race, go with their ST47's (or whatever is higher CoF than ST43) in the front and ST45's in the rear based on my experience now. With a 11.75" rotor you have a bit less leverage on the front as well.
        I race a 1st gen RX7 the vast majority of the time now and have been trying to sell the S14 for a few years. While it sits around with a for sale sign on it, I've brought it out a few times for WRL or SCCA enduro races or DE days where I just want to blow off steam. it's much less cost/hr to operate than the RX7.

        I run 245/40/17 DOT-R on the car. still using the stock VLSD, but a 1.5-way would make life lots better. could probably drop a second or so a lap if I put a good diff in it.

        I bought a set of ST43 or ST47 a while back, just never mounted them up. they're sitting in a box waiting for enough miles on the DTC70 to make it useful. if I ever get the car sold, I'll part with those pads for a good price.

        ........................

        I started on an 11.75" rear kit several years ago (so I could use same rotors front and rear and adjust bias w/ hydraulics.) I then switched to racing the RX7 and never finished it.

        using the lug mount Superlites, you have to cut the mounting ears off the stock upright and trim a bit more meat off before the lugs clear the mass at the center of the upright. you can then fairly easily weld on a chunk of 3/8" alu plate or a piece of angle and drill for the bolts to mount the caliper.
        I took the first step of hacking off the mounting ears from a set of Z32 uprights and then never finished because my TIG guy disappeared.

        Because of the necessary mofidication of the upright, it won't be a simple bolt-on bracket deal using the superlite lug mount calipers. Just is what it is. If someone wants to finish this job, I'm happy to pass my materials on at a good discount. I have a set of superlite-4 with small pistons (forget the diameter, but probably same as Def's) and a set of Z32 uprights- one hacked up already..
        Last edited by Matt93SE; 06-06-2017, 03:19 PM.
        Originally posted by SoSideways
        I don't care what color they are as long as they are LONG AND HARD.
        '04 G35 Sedan 6MT- The DD
        '96 240SX- The Track Toy

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        • Originally posted by Matt93SE View Post
          I race a 1st gen RX7 the vast majority of the time now and have been trying to sell the S14 for a few years. While it sits around with a for sale sign on it, I've brought it out a few times for WRL or SCCA enduro races or DE days where I just want to blow off steam. it's much less cost/hr to operate than the RX7.

          I run 245/40/17 DOT-R on the car. still using the stock VLSD, but a 1.5-way would make life lots better. could probably drop a second or so a lap if I put a good diff in it.

          I bought a set of ST43 or ST47 a while back, just never mounted them up. they're sitting in a box waiting for enough miles on the DTC70 to make it useful. if I ever get the car sold, I'll part with those pads for a good price.

          ........................

          I started on an 11.75" rear kit several years ago (so I could use same rotors front and rear and adjust bias w/ hydraulics.) I then switched to racing the RX7 and never finished it.

          using the lug mount Superlites, you have to cut the mounting ears off the stock upright and trim a bit more meat off before the lugs clear the mass at the center of the upright. you can then fairly easily weld on a chunk of 3/8" alu plate or a piece of angle and drill for the bolts to mount the caliper.
          I took the first step of hacking off the mounting ears from a set of Z32 uprights and then never finished because my TIG guy disappeared.

          Because of the necessary mofidication of the upright, it won't be a simple bolt-on bracket deal using the superlite lug mount calipers. Just is what it is. If someone wants to finish this job, I'm happy to pass my materials on at a good discount. I have a set of superlite-4 with small pistons (forget the diameter, but probably same as Def's) and a set of Z32 uprights- one hacked up already..
          Thanks for sharing. In my case, it may just be better to design something for the radial mount calipers then. Also, I run the steel uprights on my car. I do have Z32 uprights on the shelf, but I have a set of MCS dampers coming that are setup for S14 so they'll be staying on the shelf.

          Perhaps going with a larger rotor to match the front 12.2" defsport rotors will provide more clearance for the lug mount calipers.

          Those that are interested in a rear kit, are you running Z32 rear uprights and do you mind paying a bit more for radial mount calipers vs lug mount?
          Core4 Motorsports
          CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
          S14 VQ AER Endurance Racing Team

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          • That's for an 11.75" rotor. Things loosen up with a larger diameter rotor.
            '18 Chevrolet Volt - Electric fun hatch for DD duty!


            DefSport Koni Sleeve and Spring Perch Buy!!!
            http://www.nissanroadracing.com/showthread.php?t=5902

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            • Originally posted by Def View Post
              That's for an 11.75" rotor. Things loosen up with a larger diameter rotor.
              1/4" difference in radius doesn't make up for 1" of interference...
              The differing mounting ear spacing doesn't help.
              Originally posted by SoSideways
              I don't care what color they are as long as they are LONG AND HARD.
              '04 G35 Sedan 6MT- The DD
              '96 240SX- The Track Toy

              Comment


              • If anyone decides to make a good rear brake option I'm definitely in! I've been searching high and low, with no success. I don't have the time/resources to make something myself. A complete rear brake setup would be ideal, but I think if someone even made a hat to mount a mass produced wilwood disc with z32 calipers it would help tremendously. Obviously wouldn't help brake bias, but would take care of weight and running costs.

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                • Originally posted by Matt93SE View Post
                  1/4" difference in radius doesn't make up for 1" of interference...
                  The differing mounting ear spacing doesn't help.
                  There are larger rotors than that in the world.
                  '18 Chevrolet Volt - Electric fun hatch for DD duty!


                  DefSport Koni Sleeve and Spring Perch Buy!!!
                  http://www.nissanroadracing.com/showthread.php?t=5902

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                  • Originally posted by Def View Post
                    There are larger rotors than that in the world.
                    There's also things like rotating and unsprung mass to consider when you only have 150whp and don't need HUGE brakes, just good brakes..
                    Originally posted by SoSideways
                    I don't care what color they are as long as they are LONG AND HARD.
                    '04 G35 Sedan 6MT- The DD
                    '96 240SX- The Track Toy

                    Comment


                    • Originally posted by ericb382 View Post
                      If anyone decides to make a good rear brake option I'm definitely in! I've been searching high and low, with no success. I don't have the time/resources to make something myself. A complete rear brake setup would be ideal, but I think if someone even made a hat to mount a mass produced wilwood disc with z32 calipers it would help tremendously. Obviously wouldn't help brake bias, but would take care of weight and running costs.
                      Good to know. Are you running Z32 uprights/knuckles? And would any of you like to keep e-brake functionality? I have no need for it.

                      Not for anything, rear Z32 rotors are pretty damn cheap (Centric premium high carbon). I want something bigger/wider and/or cooling as I have bad pad transfer in the rear often.

                      In addition to what you said, using rear Wilwood calipers would allow for the same pad shape front and rear. The pad is YUUUGE and cheaper than a Z32. And if you run same pad compound front and rear, rotating pads around will add even more to useable life.
                      Core4 Motorsports
                      CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
                      S14 VQ AER Endurance Racing Team

                      Comment


                      • Originally posted by Matt93SE View Post
                        There's also things like rotating and unsprung mass to consider when you only have 150whp and don't need HUGE brakes, just good brakes..
                        That was never a problem on my car unless I unplugged a couple of coilpacks.
                        '18 Chevrolet Volt - Electric fun hatch for DD duty!


                        DefSport Koni Sleeve and Spring Perch Buy!!!
                        http://www.nissanroadracing.com/showthread.php?t=5902

                        Comment


                        • Originally posted by gills View Post
                          Good to know. Are you running Z32 uprights/knuckles? And would any of you like to keep e-brake functionality? I have no need for it.

                          Not for anything, rear Z32 rotors are pretty damn cheap (Centric premium high carbon). I want something bigger/wider and/or cooling as I have bad pad transfer in the rear often.

                          In addition to what you said, using rear Wilwood calipers would allow for the same pad shape front and rear. The pad is YUUUGE and cheaper than a Z32. And if you run same pad compound front and rear, rotating pads around will add even more to useable life.
                          I'm using gk tech rear knuckles. If I could have provisions for ebrake, I would really like it, but it's not 100% necessary. Definitely not important enough for the rotating weight penalty of z32 iron rotors. And with the gk tech knuckles if the rotors were z32 sized I should be able to come up with a dual caliper setup if I decide I want e-brake that much (I probably would considering it's "good weight" minus the unsprung portion as it would allow me to pull that much weight out of worse areas). Pad pricing is a factor, but not nearly as much as rotor pricing since nasa's hawk contingency program is so generous. I don't see ever paying for pads anyway, but more leftovers never hurt...
                          Last edited by ericb382; 06-08-2017, 11:31 PM.

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                          • I'll update here for now while I finalize this.





                            Initial mock up with printed parts. Rotor pictured is a 12.2" x 0.81" HD WW rotor. Wheel is 17x9 +18 with 5mm spacer (not required to clear caliper).
                            It's not a FSL caliper if you can't tell. To get the FSL to fit without cutting the OE caliper mounting ears off is basically impossible without maybe using some huge diameter rotor or a wacky negative offset rotor hat, as far as I can tell. Plus, the FSL is likely overkill back there.

                            The hat hardware in the picture is also full floating hardware for anyone with a keen eye. I only used it for mock up as I had it laying around for something else, which is why the orientation of the shoulder screw heads are all over the place. Overkill to go full floating in the rear, I plan on using similar hardware as the Defsport kit.

                            I decided on a Forged Narrow Dynalite, which is the most recent revision of the Dynalite series (has a center bridge bolt vs. a pin for extra rigidity), uses a larger pad (0.6" vs 0.49" thick) vs. the other Dynalite and Dynapro models (with the exception of the Dynapro 4 Radial Mount, which is almost $100 more/caliper and not even made with piston sizes that work for our application), and is very affordable. Pads are also very inexpensive vs. Z32 pads with more pad volume to boot.

                            This won't require cutting the OE mounting ears. If someone REALLY wants to use their Z32 ebrake, it'll be possible to make a barrel with a steel insert off the back of the rotor hat, but I won't be focusing on that for some time.

                            The 2 piece rotor setup weight savings is just shy of 4 lbs per corner. The caliper weight differences I need to measure still, but not sure there's much there as the Z32 rear alum calipers are pretty compact.

                            Anywho....
                            Core4 Motorsports
                            CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
                            S14 VQ AER Endurance Racing Team

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                            • PM'd you my number. I need this in my life!

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