The HKS can hold more boost, then next is the APEX because they're both pull type BOV's. Exactly how much PSI not sure, I thought figures were to about that range of 30ish. but I would say unless you're gonna drag your car to ~35 psi, you won't need to get the HKS Type2... some info from the Takakaira site on the type2 The Racing Blow-Off Valve Type II is a higly tuned version of the SSQV. Unlike the SSQV, the Type II uses a single aluminum valve to accommodate up to 3.0 bar (43.44 psi). Additionally, the Type II is engineered to work accurately on vehicles with up to 800+ horsepower. The Racing Blow-Off Valve Type II utilizes the same flange and billet aluminum construction as the SSQV.
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