Project NSX: Part 7 – Installing PFC Multi-Pad Monobloc Calipers

The 14” rotor is 30mm wide, 25mm taller and 2mm wider than the common 13” (330x28mm) brake rotor that was used in professional racing on the RealTime World Challenge NSX.

Every single PFC rotor is 100% symmetrical.  No other aftermarket or OE manufacturer can make that claim. PFC holds some of the tightest rotor casting and machining tolerances of any manufacturer.  Because of this, PFC rotors do not need to be balanced like most rotors which requires removing material from the outer rotor cooling vanes.  This can create stress risers and more importantly, affect the cooling uniformity across the rotor since part of the rotor blade (cooling vane) is missing.

PFC’s patented manufacturing process conducts a true mass study of the disc itself and laser checks them for uniformity, thickness variation, and casting flaws.  Once the casting fits their criteria, they machine the rotor from the center out without cutting oils or coolants, unlike most manufacturers.  This reduces complications with ‘green’ fade of the disc itself, which is primarily getting contaminants out of the disc and to stress relieve them.  PFC rounds all surfaces and cleans every single vane, which ensures the elimination of heat issues such as cracking or warping.

Performance Friction V2 Direct Drive Rotor

Another PFC innovation is the rotor retention and rotor to hat interface.  For decades 2-piece rotors were attached to aluminum hats via nuts, bolts, and bobbins within holes in the mounting tab of the rotor.  This design allows for significant bending of the rotor-to-hat interface, causing pad knock-back and leaving very little room for thermal expansion before the rotor bolt hardware causes a bind.

PFC solved this issue by removing the hole in the mounting tab all together, and retaining the steel rotor in the aluminum hat with a retention ring that is bolted to the hat itself (V2; V3 uses a snap-ring).  This eliminates virtually all of the bending at the disc-to-hat interface and allows for significant thermal expansion of the rotor and retention within the hat without any possible binding.  Controversially, this design was copied by almost every brake manufacturer and used in their top-tier professional racing efforts.  If you go to any pro race and look at a car with iron brakes, you’ll likely see Performance Friction’s rotor retention design in use.

PFC’s rotor retention has gone through three different generations.  Our car has the V2 design while the new V3 is even lighter by using a snap ring in replacement of hardware to retain the rotor.

8 comments

  1. OK, that’s just lovely. Wish the multipad stuff was more commonplace but even the “budget” ZR34/ZR94 calipers look pretty nice.

  2. Any idea if the NSX ABS module is similar to the S2k stuff? I am kicking around adding the S2k ABS system to my 240sx as it is a self contained standalone setup. Would be nice to go from no ABS to something more modern and workable.

    1. It’s somewhat similar. The programming is different and there are some hardware differences. People have used it on the NSX but I do not how know it performs vs a system designed for the NSX, however for your application it may be a better option.

  3. I had no idea individual pads were so rare in the automotive world. In the motorcycle industry, lots of even stock calipers use 4 individual pads.

  4. Neat. A lot of new information in this thread. I am one of those people who thought PFC was left only for those in NASCAR circles etc. I have a 328mm Stoptech ST40 kit behind 18″ TE37s. I thought they were cool (just like Milhouse’s mom), but you said otherwise.

    1. They’ve been in formula cars, prototypes, and sportscars for decades. I never said anything bad about StopTech. They are a great product at a great price point and put far more engineering and focus on brake bias for each application than their competitors.

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