I have a 2000 Silverado 5.3 with Lt headers, no cats, 3" y pipe into a borla xr1 dumped right before the back axle. Before I got headers I had ran straights, glasspacks, and flowmaster 40 and was never happy with the sound. Now that I have headers and no cats I figured the borla xr1 would be pretty loud, but its not. Its practically silent at idle, but sounds good as I progress. I'm just wondering why every exhaust set up I've had has been so quiet when I have heard the same truck with the same exhaust make 5x more noise than me. Could it be wrong gap on spark plugs? Or anything by that nature? And help would be appreciated!

 

Cant really help you but I experienced this exact thing, on my old 6.0l sierra I had stock manifolds and cats through a DI DO 22" muffler and It was loud!! Now on my 6.0l Silverado I have the exact same setup minus the cats so it should be even louder, but it is way quieter

 

I wonder what the cause of this is. Hopefully someone will chime in and help us out

 

Maybe y'all are going deaf????? Lol

 

Lol maybe I am! I don't think that's it but two kicker l7 12's might alter someone's hearing a little bit lol