Every import gets a bad rap for having a big exhaust. Well, I am no different. But here is the key: I actually need the big bore piping and 4" tip. Exhaust gasses must be evacuated quickly so the turbo can do its job. The less resistance (back pressure) the exhaust has, the faster the turbo can be at peak pressure generation (spool up) and the more responsive the turbo and engine are as a team. In a non-turbo car, big exhausts rob power and make a lot of noise, where the turbo itself acts a noise suppression device on a car equipped with one. A 3" Project Silvia (now discontinued) dump pipe (O2 sensor housing and turbo extension are also common names) follows right after the turbo and is much larger and higher flowing than the stock 2" piece. Following is a matching Project Silvia 3" downpipe (called B pipe as well) and Project Silvia Test pipe that replaces the catalytic converter with a less restrictive open pipe. Note: This is illegal on any road driven car built after 1976. I am cool with that. The cops aren't. But since the motor itself is technically illegal as well, who cares. Following the test pipe is a HKS Hi Power stainless steel "cat back" exhaust. Utilizing even larger 95mm piping and a 120mm tip, the HKS flows outstandingly, but since it comes with a resonator, the exhaust is surprisingly mellow and deep, if I don't dip into boost, I can slip through traffic with nary a sound (especially compared to the big diesels that so many folks drive around here). Gotta love that. Plus, it looks sooo hot...