350Z Exhaust expansion chamber

On my 350Z I recenctly designed and installed an expansion chamber to the factory exhaust system. By removing the section of pipe which contains the resonator and replacing it with a 34" X 3" tapered chamber to settle the exhaust prior to the muffler. What an improvment, a much nicer exhaust note, slightly more pronounced throat. But with a significant increase in torque and freedom to rev. May be something to try for under $200.00 before you spend $1400.00 on a full system.