[dsraven]

exhaust blows oxides of nitrogen and moisture out the tailpipe. if you dump before the rear of the truck and you have any bare metal or unprotected surfaces you can start to see corrosion start. it also dumps heat so everything behind it warms up in traffic. I suggest to try getting the pipes out the rear or the side instead of onto the ground below the truck. just my 2 cents worth. I have done it that way, dumping ahead of the axle because of room constraints. it's definitely loud in the cab and you start seeing the rock chips rusting up as well as more chips because the exhaust blows into the dirt. it also warms up the rear axle if dumping out in the right spot for the heat to hit the housing. long trips leave your ears ringing. on the bright side though, if you drive it that way for long enough you can't hear it anymore (or much else....)