Forge motorsport also sells a very good valve for all the Lancer Evolutions. It’s called the Forge RS. It recirculates the air back so that the car does not jump in between shifts and doesn’t stall. It works very very well. All Forge Motorsport products are CNC machined and polished by machine and anodized clear so that you don’t have to keep polishing the valves and they stay at a really good luster and are protected from corrosion throughout their lifetime. This is very important in the high-heat engine bay environment where moisture from rain and condensation is common.