i made my own exhaust i put pieces together from things i thought would make it sound good and it does it sounds nice and quiet and deep when im driving normal but opens up when i get on it...Its a complete flow through design. 4-1 headers, High flow cat completely hollow just sound muffling stuff around the sides, then it goes to a cherry bomb, from there to a high flow muffler. Just a suggestion sounds great and have been complimented on the sound several times.