if you want an hks for big horsepower just get this:
"The HKS Racing Blow Off Valve Type II is a pull-type blow off valve for high horsepower applications. Similar in construction and function to the HKS SSQV, the Racing Blow Off Valve Type II uses a large single stage, aluminum pull-type valve to handle the extreme pressure and airflow discharge volume that is associated with high boost / horsepower applications. The Type II is engineered to accommodate up to 3.0 bar (43.44psi) of boost and can function accurately on vehicles in the 800 horsepower range. "
http://www.hksusa.com/products/?id=759