WPC is Neat Stuff!
If you are a longtime MotoIQ reader you will probably know that we are big fans of the WPC process and use it extensively in many of our engine build projects and wherever we need durability and lower friction of a part from transmissions to limited slip differentials.
WPC is a metal improvement process, developed in Japan and available through their U.S. arm in Torrance, California, very close to the luxurious and palatial MotoIQ headquarters.
WPC is a well kept motorsports secret that is used extensively at high levels of the sport, such as Super GT (JGTC), MotoGP and WRC. Recently WPC has been gaining popularity in North America in venues such as Pro Stock drag racing, IRL, ALMS and NASCAR. WPC is also gaining acceptance from the OE auto and motorcycle manufacturers such as Nissan, Honda and Yamaha as a better performing alternative to coatings to enhance wear resistance, extend service life and to reduce friction.
WPC is very secretive about their exact process but we have been able to glean a few important details from indirect observation and our own personal experience with the process. Contrary to popular belief, WPC is not a coating; it is closely related to shotpeening except WPC is done in a very different manner. Like shotpeening, WPC involves impacting a part with spherical projectiles to produce surface compressive stress, plastic deformation and grain refinement. Again, much like shotpeening, this action greatly improves fatigue strength and stress corrosion fracture resistance. However WPC differs from shotpeening in that the peening media is several orders of magnitude smaller, much harder and the impact velocities are much higher.
Check out this video showing some of WPC's anti friction properties and how the unique surface finish manipulates the boundary layer between two surfaces to have an air bearing effect with sealing!
Although WPC will not divulge exactly what their media is made from, it resembles baby powder to the casual observer. We believe that the material is some sort of ultra hard ceramic whose dimensions and roundness can be precisely controlled like silicon nitride. These spheres are in the low micron range size wise and the impact velocities are near sonic in speed. We also believe that metallic additives such a zinc, tin and molybdenum disulfide are present in the mix to add some anti-galling lubricity or extreme pressure characteristics to the surface. At high velocities, the additives are probably inter-granularly incorporated into the surface of the metal at a molecular level, making their effects long lasting or even permanent. We asked the folks at WPC to confirm this but they sort of just smiled and said nothing.
Check out this video showing some amazing anti friction properties vs a polished surface using a DLC coated lifter bucket.
WPC is amazingly good stuff that we have found to be effective on everything from go karts to improving reliability on tightly fitted match target guns. We have yet to find a disadvantage or trade off to WPC treatment in anything that we have used it on to date.
We encourage you to give WPC a try, you will not be disappointed.