3.5" Turboback 321 Stainless Steel Exhaust by Unobtainium Welding (DPF/SCR/Urea deleted)
GSR Technik Flash Tune (Now called HD Tuning) for about 3 years; great tune!
Recently switched to a DUDMD tune (2 years) and it's also very good and fixed a midrange issue that I could've had fixed with HD, however I wanted to try DudMD and the experience was flawless.
Test rev before tuning:
Modification to original design:
Before and After Tips
Tips Modified To Larger Extended Versions
