I was driving behind an F-350 turbo diesel a couple of days ago and heard what sounded like a semi-truck approaching. I looked around, as this road is not normally used by large trucks, and could not find the semi in question. As we pulled away from a stop sign I noticed the sound was coming from the F350 turbo in front of me but it sounded (most accurately) like a 6 engined tractor one sees and hears at a tractor pull. The sound was a high pitched whirr and the sound increased when the pickup gained speed.

Anyone familiar with this type of exhaust and where I might find information about it?

 

could be anything that is on the market, even straight pipes. who knows. without hearing it or best yet talking to the owner you will or might never know.

 

ahhh....Powerstroke + straight pipes =