HKS Legal Max stainless exhaust (Y-pipe back) for R35 GTR. HKS Legamax Premium Exhaust, Stainless Steel, Quad Tip: R35 GT-R HKS produces this stainless steel exhaust system with four titanium tips. The unique pipe configuration and affordable price using stainless steel are the main draws to this system. Sound is kept nearly the same as OEM. OEM dB rating is 88dB whereas this HKS exhaust is 89dB.