Yashio Factory Super Silent Titanium Muffler (S13/180SX)

Although it is a 76.3φ pipe, the titanium material is 1 mm thick, so the inner diameter is 74.3φ. Just for your reference, if it is a stainless steel material, even 80φ is 1.5 mm thick, so it is 77φ. The volume of the noise is reduced without losing the power by throwing the 76.3φ pipe inside of the sub-muffler, and 70φ for the main pipe, Driving noise that you can hear inside the car can be unpleasant. It shouldn’t disturb the tunes coming out of your stereo of course! However, you still need that “thick” sound because you are driving a tuned car. And let me tell you, this muffler “speaks” all that!