HKS Carbon-Ti Exhaust 300ZX 1990-1996 Turbo. Assemblies are the same high-quality units used in the HKS bolt-on exhaust systems. The 170mm Carbon Ti muffler shell design is available in 75mm piping diameter. The 130mm Carbon Ti muffler shell design is available in 60mm piping diameter for use with custom exhaust applications. Each assembly comes with a polished stainless mounting bracket for separate hangers to be welded onto.