Why three stacks?

**Mr Ed** · 03.18.2012

Must be for those new 9 cylinder engines.

**SHC** · 03.18.2012

Originally Posted by superhauler

if smoke aint coming out the stacks you aint a trucking period!!

CARB would care to differ on this lol

**Gearjammin' Penguin** · 03.18.2012

Originally Posted by fortycalglock

It looks like a project that wasn't completed.

Much like the owner's brain.

**skellr** · 03.18.2012

Truck is so bad it needs three stacks.

**Truck Driver** · 03.18.2012

All the trucks I've seen with three stacks have been container haulers that run out of the ports in CA. Usually a truck that had stacks behind the doors. You can't enter the ports with a truck older than a certain year without a particulate filter, so a lot of those trucks have an aftermarket stack with a filter behind the sleeper and leave the old stacks on for looks. Its always a weird thing to see.

**Calve** · 03.19.2012

My uncle did this with his truck. Came time for him to replace the mufflers and exhaust on his truck, figured it was stupid money for the mufflers, replumbed his exhaust but couldn't take off the pipes due to holes in his body. So he just kept them on his truck. The back one is functional, the front two are just there.

Originally Posted by Mardet

I guess I haven't been around as long as I thought because I have not seen this before. Why the three exhaust stacks?

**SHC** · 03.19.2012

Originally Posted by Calve

My uncle did this with his truck. Came time for him to replace the mufflers and exhaust on his truck, figured it was stupid money for the mufflers, replumbed his exhaust but couldn't take off the pipes due to holes in his body. So he just kept them on his truck. The back one is functional, the front two are just there.

Replacement mufflers are $89 thru Truckpro or Ryder, so that makes it odd he spent more on plumbing a new exhaust??

**SHC** · 03.19.2012

Originally Posted by Truck Driver

All the trucks I've seen with three stacks have been container haulers that run out of the ports in CA. Usually a truck that had stacks behind the doors. You can't enter the ports with a truck older than a certain year without a particulate filter, so a lot of those trucks have an aftermarket stack with a filter behind the sleeper and leave the old stacks on for looks. Its always a weird thing to see.

Good call. The one in the picture has a DPF stack (behind the cab) so that could be the reason why.

**Brandonpdx** · 03.19.2012

Originally Posted by fortycalglock

It looks like a project that wasn't completed.

Yeah beat me to it. Looks like he was putting dual stacks on but didn't get it finished for whatever reason

**Rat** · 03.19.2012

Originally Posted by SHC

Actually PACCAR does that quite a bit now, but all the ones I have seen had dummy stacks on the sides of the cab as usual and the real exhaust exited under the truck. They do this because the new trucks exhaust gets so hot when it regen's that it will blue and melt a regular chrome stack. If you notice on trucks with a DPF system, they have what they called "inter cooled" stacks, in which where the tip has an inner and outter side to it. They do this to keep the shiny chrome from peeling off. No idea why this guy ran 3 stacks, cuz the whole point is to keep it clean appearance

Many custom truck builders run those 8" and 9" stacks on the sides of trucks and place the working exhaust out the bottom by the rear axle, so they don't ruin and carbon the big expensive pipes.

Sorry, we have alot of new paccar trucks in our fleet with stacks and they do not have a seperate weed burner exhaust on them. The stacks are fully functional.