Kyosho IF347-128 Big Shock Piston 1.2x8 Hole

Shock pistons for Kyosho's Big Bore dampers, drilled with eight holes of 1.2mm diameter.

The piston is the disc that travels through the oil inside the shock body, and the total open area of its holes is what actually controls damping. More holes, or larger holes, let oil pass more freely and give faster, softer damping. Fewer or smaller holes restrict flow and slow the suspension down.

Eight holes at 1.2mm gives a large total flow area from many small openings rather than a few big ones, which produces a distinctly different feel to the same area drilled as fewer larger holes. Many small holes tend to make damping more speed-sensitive, so the shock stays supple over small chatter but firms up more noticeably on fast, high-energy inputs like jump landings.

Piston choice works together with oil weight, and it is common to pair a more open piston with heavier oil for better big-hit control than a restrictive piston with light oil can give. Kyosho positions these as setup parts to change with track and seasonal conditions. Fitment covers the Inferno MP10, MP10 TKI3, MP10T, MP10e, MP9 TKI4 V2 and Inferno NEO 3.0 and 4.0 VE.