BILSTEIN’s New Piston Choices Provide Versatility to Racers


Poway, California, August 16, 2018 – Proper adjustments win races, which is why BILSTEIN is introducing three new shock piston choices that provide racers greater flexibility to meet changing track conditions.

The company’s newest competition piston offerings include: 46mm Digressive/Linear, 46mm High-Flow Linear and Two-Port Linear systems.

They join BILSTEIN’s championship-proven standard U37T linear piston and revolutionary C.O.B. digressive piston that utilizes an optional “Compression Only Bypass” check valve to bring race car handling to OE auto manufacturers while maintaining a compliant ride for their customers.

“Racers want options,” said Jim Hiland of BILSTEIN, a thyssenkrupp company. “Building on our extremely successful legacy piston designs, these new pistons give competitors the versatility they need for subtle suspension changes that can make all the difference on race day.”


The 46mm Digressive/Linear piston features two distinct sides: one for fully digressive valvings and the other for linear valvings. The digressive side is designed for optional use with BILSTEIN’s famous c.o.b. check valve system.

“BILSTEIN engineers married up the linear compression to the c.o.b. digressive rebound for the best of both worlds in our new Digressive/Linear piston,” Hiland noted. “Now, the same top-of-the-line BILSTEIN piston characteristics are together on one new, very versatile piston.”

Continuous piston band with no end gap is available.
Recess to accommodate optional actuator O-ring creating a better piston-band-to-shock-wall seal.
Available pre-load depth is three times the the company’s standard digressive piston.
C.O.B. check valve on the rebound side.
Extra-deep pre-load area allows rebound zero points of over 2,500 pounds.
Famous Bilstein quality spring steel shims so that using this piston will not require a new stock of shims.
Part Numbers: E4-WMP-0846C00 (8mm), E4-WMP-1246C00 (12mm)

The 46mm High-Flow Linear is a high-bleed symmetrical linear piston that can be mated with two widths of continuous piston band backed by an actuator O-ring (sold separately). One width is for standard operation and the other is a narrower option for added high-frequency damping.

Soft linear valvings—to create big grip forces at the tire patch on slick racing surfaces.
Continuous piston band and actuator O-ring reduce the amount of unmetered bleed.
Narrow “sliding” piston band is available to enhance high-frequency characteristics.
Superior hysteresis characteristics result in increased grip at the tire patch compared to other brands.
Part Numbers: E4-MWP-0846A00 (8mm), E4-WMP-1246A02 (12mm)
To learn more about BILSTEIN’s new line of pistons, contact the technical department at 877-666-7662 or go to