Subaru EJ20 WRX-STi 8.5:1 ZRP 1400HD Forged Pistons by Wiseco

ZRP, in collaboration with Wiseco, created a unique new series of pistons made in the USA from 2618 alloy and share many advanced features with the Wiseco HD1400 series for Extreme High HP setups.

The pistons include upgraded pins with 5.34mm wall thickness and Armor Plating piston coating to reduce the ill effects of high heat in turbo and nitrous/methanol setups. Each ZRP piston in this application includes an ArmorGlide anti-friction skirt coating to minimize scuffing during break-in and reduce friction on the cylinder wall. Our pistons are made from dedicated in-house forgings, providing a lightweight piston with superior strength and optimal design. Also, the valve pockets are bigger and deeper than OEM in order to accept high-lift camshafts. Moreover, the pistons have offset pins and Gas-Pressure and Anti-Detonation grooves to prolong ring longevity!

What is the Armor Plating piston coating?

The Armor Plating Coating gives them a bronze tint on the top and wrist pin bore. This abrasion-resistant plating increases the aluminum's hardness, enhances the ring grooves' durability, prevents micro-welding of the piston rings, reduces carbon buildup, and combats corrosion from detonation. Also, the Armor Plating coating reduces the piston crown temperature by 20c on average!

What is the ArmorGlide anti-friction skirt coating?

ArmorGlide skirt coating is made from Molly solid film lubricant and is permanently bonded to the pistons. One main feature is creating seizure resistance and reducing friction, ensuring quiet operation. Of course, there is less piston rock, reduced noise, and increased power.