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Response Type BIG BRAKE kit, 13 inches for non-turbo hubs :)

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  • Hubs machined...outer diameter (pentagon) had to be rounded and inner diameter had to be machined slightly to fit. Everything looks good now though.
    Usual Z31 suspect: Garage Queen (aka broken)

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    • fuck a duck





      Couldn't get the other side on because (Queue laughter), I couldn't get the fucking dust shield off. 3 little screws weren't having it and I was tired.
      Usual Z31 suspect: Garage Queen (aka broken)

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      • Cut the shield with tin snips, if you manage to cut it so that you have three individual pieces, you can wiggle them, that usually frees the screws... so far I've removed shields on 3 chassis only braking 1 of the bolts, which was easy to drill out backwards

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        • Ive got some small vice grips that I'll take to them and it should be out in seconds. Just didn't even care anymore since i still have to remove the hubs to repack them with grease. Wanted to get the rears on then got hit by a severe t-storm where trees were coming down and lightening was striking everywhere (had to drive a couple miles home).
          Usual Z31 suspect: Garage Queen (aka broken)

          Comment


          • I'm going to throw these up at a discount for april fool's week... $959+ship

            If you combine other items and break $1500, I'll do free shipping on everything** !!!

            ** = to most of usa/canada

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            • I just refactored based on the exchange rate... now that USD is 1.1x CAD... lucky americans

              I can offer these kits for $875+ship all day long!

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              • Titanium "heat shields" for pads, really they are backing plates but they make a huge difference in keeping heat out of the caliper and fluid... the downside is the heat stays in the pad, so you need higher temp rated pads if you go racing

                Linky: http://hardbrakes.com/index.php?main...roducts_id=134

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                • Response Type 13" BBK vs. CTS-V + 14" Akebono BBK

                  Why larger isn't always better...

                  --- MASS

                  We all know unsprung mass degrades the ability of suspension components to do their work suspending the chassis, but there's two kinds, static and rotating mass.

                  If you ever had the joy of growing up in the analog world, with those wind up cars with those heavy flywheels to store your energy, you'll understand how powerful rotating mass can be -- now imagine you had to fight it.

                  Without melting anyone's brain with calculations, let's just simplify the rotor into a radial center of mass (the rotating mass increases leverage with a larger radius), and a total mass for direct comparisons.

                  1. the 13" 2-piece rt.trackpro rotors have a mass of 18.7lbs
                  2. the 14" akebono rotors weigh 30.8lbs.
                  3. crucially the radial center is just under 3/4" further out for the akebono

                  In summary: The 14" rotor has about 42% more rotational mass in the rotor, mass that gets multiplied with velocity...

                  --- TORQUE

                  The CTS-V calipers have a slight mechanical advantage, the braking torque from the pistons is very close leaning in the CTS-V's favour, but also a small advantage is given to the CTS-V caliper again for pad area.

                  In summary: The CTS-V caliper has about 15-18% more torque than the RT Big black caliper.

                  Does that extra brake torque with the CTS-V caliper overcome the massive increase in rotational mass? There will be a speed above which the answer is NO, just like aerodynamic drag will become a larger factor than vehicle weight above a certain speed.

                  Remember, the faster the rotor spins, the faster the rotational mass gains momentum, momentum which then fights changing speed like a gyroscope. Having a ton of extra mass in the rotor (that has to be accelerated and decelerated constantly), makes the car less responsive to gaining speed, and will also fight the calipers while braking.

                  --- STEERING

                  There's another aspect to this brake kit that won't be obvious without having it in hand, and that is the actual rotor distance from the steering axis.

                  The rt.trackpro rotors are designed so that the heavy "ring" sits as far inboard as possible without hitting anything; without using the rt.trackpro rollcenter adjuster kit, the end of the control arm actually floats inside the rotor! The bottom portion of the ring actually crosses the steering axis.

                  The akebono rotors as well as most of the nissan rotors have fairly short hats, which simply put means they sit 20mm or further outboard.

                  When making rapid turns, such as a slalom or possibly quick corrections to maintain balance on a track, the extra leverage of a shorter hat, coupled with a heavier rotor will make steering more difficult.

                  In summary: This may not be a serious concern with power steering, but for anyone with a manual (or manualized) rack will definitely notice the effort increase.

                  --- WHEELS

                  And finally, there's wheel clearance.

                  Having such tall hats, the rt.trackpro rotors give you about as little caliper profile clearance as possible for a big brake kit. The calipers in the RT BBK protrude approximately 15/16" from the face of the rotor, and have more curvature to them than the sumitomo calipers used on the R32 and Z32.

                  Most of the large calipers have an overall width between 150-165mm, half of which will be outboard of the rotor ring's center line. If a rotor has a hat height of 25mm, with a ring thickness of 32mm, and a caliper width of 160mm: 160/2 - 32/2 - 25 = 39mm of protruding caliper beyond the hat face.

                  Based on rough measurements, the example above is pretty close to what's observed for the CTS-V + akebono pairing, approximately 1.5" of protruding caliper.

                  In summary: If your wheels are designed for big brakes, you should be fine for clearance, but medium disc wheels which clear the rt.trackpro BBK, may not clear the CTS-V + akebono kit.

                  ---

                  Nitpicking a design down to the last millimeter can pay dividends

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                  • Mine came preloaded with the pads and I was wondering if everything was greased up already. Also I am having a rubbing sound at a certain point of rotation. It looks like the pad retainer is rubbing on the rotor and it is quite loud. Any thoughts? A bit tired at this point and trying to get a game plan for tomorrow.
                    Daily:
                    09 2.5SL Altima Grey
                    08 4.0SE Pathfinder 4x4 Grey
                    11 Ducati Diavel Carbon Red
                    Z31s:
                    88t Grey
                    86t Pewter

                    Comment


                    • Actually it is the retainer/spring rubbing the rotor... Ended up bending them slightly and problem gone. Was only an issue on one side. Wondering if the spring was out of spec.
                      Last edited by utjon; 10-22-2020, 05:52 PM.
                      Daily:
                      09 2.5SL Altima Grey
                      08 4.0SE Pathfinder 4x4 Grey
                      11 Ducati Diavel Carbon Red
                      Z31s:
                      88t Grey
                      86t Pewter

                      Comment

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