• Extreme Duty Series exhaust valve, stainless steel
• Proven in Top Fuel, Funny Car, and circle track racing
• Built for the most demanding professional racing applications
• Available as single valve or full set

Technology Proven in the Most Extreme Motorsports

Manley's Extreme Duty Series Valves are engineered to cater to the demanding needs of Top Fuel and Funny Car drag racers, Big Block Chevy marine enthusiasts, and Small Block Chevy restricted carburetor circle track competitors. That's about as demanding a proving ground as exists in motorsports, and the material science and construction that comes out of it directly benefits this valve's application on a turbocharged Subaru. These valves are your ticket to genuinely unparalleled performance rather than a repackaged standard valve. It's the kind of upgrade that quietly does its job without ever needing a second thought.

Extraordinary Capability Brought to a Street-Built Engine

Bringing this level of engineering to an EJ20-based build means access to valve technology that most street car parts catalogs simply don't offer. That's a meaningful upgrade for anyone building an engine that needs to survive genuinely extreme conditions, whether that's sustained high boost, high RPM, or repeated hard track use. It's the kind of valve you choose when failure isn't an acceptable outcome. That's real, functional engineering, not just a marketing claim.

Straight From Subispeed

Genuinely extreme-duty valve technology for 2002-2012 WRX / 2004-2012 STI, proven in some of the most demanding motorsports applications that exist.

This Part Fits:

This is the 32mm head diameter set.