HKS 4-2-1 Race Header - Honda - S2000 AP1/AP2Specifications: Manufacturer: HKS Reference Number: 33002 AH001 Type: Header Material: Stainless Steel HKS Exhaust technology, which is know how of long time development, targets to pull out 100% engine performance with the exhaust manifold. A lot of different approach were tried for each vehicle to keep performance for middle rpm range and to improve horsepower at high rpm. When strong vacuum is created, to the contrary, there will also be strong