The WPC treatment process involves hitting the metal surface with a specific media at high speeds, resulting in a hard micro dimpled surface.

When engine builders are fighting to stay in business and racers are looking for sponsors to fund their programmes, anything that adds cost to an engine construction is a tough sell.

Today, it is essential to employ value-added techniques that provide considerable advantages in engine performance and lifetime.

Spending extra on your engine build will save you money in the long run. 

WPC is one such procedure. WPC is a unique technique with a wide spectrum of favourable features.

Contrary to popular misconception, WPC is a metal surface treatment method created in Japan, not a coating. WPC is a well-kept secret that is widely employed at the highest levels of the sport.

WPC has recently gained prominence in Pro Stock drag racing, IRL, ALMS, and NASCAR in North America. 

WPC is also gaining favour with OEM auto and motorcycle manufacturers such as Honda and Yamaha as a superior alternative to coatings for improving wear resistance, extending service life, and reducing friction.

WPC is tight-lipped about its exact process, but I have gleaned a few critical features by interviewing experts and having personal experience with it.

WPC, like shot-peening, involves striking a part with spherical bullets to generate surface compressive stress, plastic deformation, and grain refinement. This action, like shot-peening, considerably improves fatigue strength and stress corrosion fracture resistance.

WPC, however, differs from shot-peening in that the peening media is several orders of magnitude smaller, much harder, and the impact velocities are much higher.

Although WPC does not reveal the specific composition of its media, it appears to be baby powder to the untrained eye. I believe the substance is an ultra-hard ceramic (experts at MotoIQ believe so, too) whose size and roundness, like silicon nitride, can be precisely regulated.

These balls are in the low micron range, almost microscopic, and their impact velocities approach sonic speeds. 

I also believe that additions such as zinc, tin, and molybdenum disulfide are added to the mix to provide anti-galling lubricity or severe pressure characteristics to the surface.

At high velocities, the additives are likely inter-granularly absorbed into the metal's surface at a molecular level, making their effects permanent and long-lasting. 

WPC has some advantages over shot-peening. WPC produces more compressive stress and a higher degree of grain refinement to the base metal than shot-peening due to the small low mass bullets and high impact velocity.

The velocities are so high that, in addition to shot-peening-like grain refining by cold working, there is also a melting and quenching phenomenon occurring at the micro-level.

While shot-peening has only a little effect on surface hardness and strength, the outcome of WPC is an exceptionally fine-grained, slip plane-free nanocrystalline structure with a high degree of surface hardness. 

When properly applied, the residual surface compressive stress from shot peening will improve fracture resistance, starting at the surface of the loaded metal components. 

Using a special combination of ceramic substrates and chemicals, the two-step process first destroys the microscopically high material points before the second pass browns the part and removes the first-stage film. 

These processes save a lot of money on component breakdowns and maintenance and reduce DNF in racing.