Discussion Starter · #1 ·
I have an '03 Duramax CC dually with 50K. I put an Edge card (Attitude with Juice) on it two months ago. That gave it some serious HP at the starting line and I could break the rear duals loose. Last week I had a 4" exhaust put on front to back (straight pipe). (This rig also never had a Cat!) The first thing I noticed was the NOISE ! The second, and more important thing, was that I lost all of the bottom end I had before and couldn't break the duals loose anymore. I talked with the Edge people and the guy who installed it, and they both said that the Turbo needed a certain amount of backpressure to operate correctly. I did notice that my Boost numbers were lower at the starting line with the 4" exhaust. I went back to the exhaust installer and we decided to put a stock 4" muffler back on. I got about 1/2 the bottom end back and the PU was quieter than Stock. Before I pay to put everything back the way it was: has anybody else experienced this and what did they do about it?