Skunk2 Racing Pro Series Honda/Acura K-Series i-VTEC XP Valve Spring Set - 311-05-7380Find parts that fit my vehicle

Skunk2 is proud to introduce its Pro Series XP (Extra Pressure) Racing Valve Spring Kits for the Honda K-series i-VTEC engines. Each kit includes Skunk2's high-quality race-proven dual valve springs that are the result of nearly two decades of racing and engine building experience. 'XP' features a higher seat pressure for turbocharged and extreme high RPM motors. This spring has a seat pressure of 100lbs @ 1.600 in. while keeping the coil bind height for higher lift camshafts. Each Pro Series XP Racing Valve Spring is manufactured exclusively from super-clean, chrome-silicone wire milled in Japan. By using inner and outer springs mated together through a slight interference fit and with differing frequencies, Pro Series XP Racing Valve Springs are able to prevent valve float and maintain valvetrain stability at engine speeds in excess of 11,000 rpm. Wound by a premier North American winder, our Pro Series XP Racing Valve Springs retains its durability and strength that results in improvement to the extreme fatigue limit of the wire and enhanced resistance to load loss. Pro Series XP Racing Valve Springs are engineered to handle the demands of extreme-lift camshafts operating at prolonged, high-rpm use at championship-level racing. Skunk2's Pro Series XP Racing Valve Spring's for the Honda's K-series i-VTEC engines are simply the best on the market. Pro Series XP Racing Valve Springs have been tested at speeds exceeding 11,000 rpm on our engine dyno, street, and the race track. Our superior, Japanese-milled, super-clean chrome silicone wire is 100-percent eddy-current inspected prior to coiling. Next, they are heat-treated, shot-peened, and chemically polished for strength and durability. A special nitriding process concludes Skunk2's rigorous manufacturing process.

Whether its for a full rebuild or some standard maintenance, the proper engine components are needed to make sure your vehicle is running smooth.

Upgrading your valve springs and retainers is the best way to help your car rev higher. If you are looking to increase the horsepower of your engine, your may have considered rebuilding the head. When rebuilding your engine's head, we recommend upgrading your valves, and springs. This will increase airflow and the RPM of your engine.

All Skunk2 products are carefully planned and designed in-house using the latest computer simulation and modeling techniques, followed by careful testing in controlled laboratory environments using state-of-the-art equipment. Each product is then subjected to rigorous dyno, street, and race track testing to ensure proper performance in the most extreme conditions. For these reasons, top street cars and race cars worldwide rely on Skunk2 products.

As part of Skunk2's commitment to developing industry-leading products, we've remained actively involved in various forms of motorsports through technical partnerships, sponsorships, as well as with our own race vehicles for more than 15 years. We've gone on to secure a number of drag racing and road racing records and championships, including earning the title of the world's first 10-second naturally aspirated Honda. Racing provides us with the data necessary to produce high-performance parts utilizing innovative designs, advanced metal alloys, cutting-edge manufacturing methods, and stringent quality-control measures.

Driven by the desire to make things go faster, Skunk2's staff is comprised of industry leaders, racers, and enthusiasts who are passionate about what they do and understand what other enthusiasts want. Our perspective is shaped by real-world racing experiences as well as by practical science, and that's precisely what makes Skunk2 products so good. Firmly grounded in our understanding of engineering, we make every effort to embrace advanced technology. Our goal is to make performance and technology accessible to other enthusiasts through innovative manufacturing techniques.

Since 1994, we've released a number of industry-leading products, including the first cast aluminum, high-performance intake manifold, cutting-edge composite fuel rails, and valvetrain components made from premium materials. Skunk2 is acclaimed as being the first U.S.-based sport compact parts manufacturer to offer CNC-machined, adjustable cam gears in 1995 as well as billet camshafts in 1999. As a result of continually pushing our engine development capabilities in the racing world, we've discovered a number of exciting "power secrets" that are incorporated into every Skunk2 product.

Today we continue our tradition of creating leading-edge products through a state-of-the-art engineering and R&D department as well as through extensive engine development and testing both on the race track and the street.