I finished installing my 4" stainless steel exhaust on my Tahoe today. Talk about trying to pack 10 pounds of stuff into a 5 pound sack. I see that everyone has a different result from this upgrade as far as turbo noise and loudness. Before my exhaust was a 2.5 inch pipe in place of the muffler and that was where the exhaust ended just past the torsion bar bracket, my turbo sang loud and beautiful but the exhaust was so loud it was hard to have a conversation with the passengers. Now my turbo sound is gone and now I have a deep sound like a sixty's muscle car. Initially I missed the turbo sound until I realized how quietly and quickly I was flying past the speed limit. The noise is much less and thankfully so, from my truck I was able to have a normal voice conversation with my wife in her truck while both were running. Now I hear little noises I never heard before like the vacuum pump and the fuel pump. It feels like there's more power, I'm looking forward to more driving time tommorrow. :D