I want stacks so bad but i dont want to have to split them in the bed. thatd just take up way too much room plus i think it looks kinda bad (just my 2 cents) so i was gonna run 4in flex tubing from the trubo back in to some stacks. First is it possible to create a downpipe out of that stuff. its flexible so i was thinkin about havin the neighbor take off the down pipe and havin him shape the flex tubin in to the shape of the old downpipe. would that work? and second question how can i run my tubin so only the stacks come out of the bed. or am i gonna have to take the hit and just have to cover up the tubin in the bed whe some diamon plate or somethin? Input for a new guy would be great and if these ideas helped any one thats great too.

 

I don't think flex pipe will bend tight enough to make a downpipe. Also, flex pipe is not real good from a flow perspective, the rough sides mess up the flow. I'd rather run the stock 3" to the stack setup than 4" flex.

As far as splitting under the truck: I don't see how you could do the left side because the fuel tank is in the way. There is just enough room on the right between the frame and the bed for 4" tubing, so you could do a single that just came up in the corner.

I think the best way to do it is to split it in the bed even though you do lose space. I'm working on a setup right now using a chunk of 6 x 10 square tube for a splitter/resonator, still hunting for some more scraps before I start cutting and welding. The 6 x 10 tube will lay on the 10" side, this will allow the stacks to be at the front of the bed while giving room for the exhaust pipe to clear the crossmember under the front of the bed. I'll lose 1 foot of bed. And I'll gain some traction in the winter, that chunk of square tube weighs at least 150 #, and I haven't welded any pipes or brackets on or plated the ends over yet.

 

I am in the process of making my stack set up right now I am using a piece of 6"x4" tubing as a splitter and having it stand up off the floor of the bed so I don't loose any actual floor length. I have welded to pieces of 5" on the top to put the chrome stacks on. I will then go through the floor with a piece of 4" then a 90* elbow and a small piece of flex to isolate it from the vibrations. I will have well less than $200 in the whole system when I am done.

 

So where is a good place to get mandrel bent 4" pipes? I think if I get a coupld of 180 degree bends, and some straight pipes, I can fab up my own setup, and need to find two 4" to 5" adapters.

 

nothing wrong w/ flex pipe... every 18 wheeler on earth uses it...

I'd rather run 4" flex pipe from turbo to tail than 3" pipe!

Forrest

 

you will find flexpipe on every 18 wheeler , but you will find that it is never more than 28 inches and not less than 8 in. , and is only use to isolate the engine mounted exhaust piping to the frame mounted exhaust piping .

 

it flows better than crimp bent exhaust pipe

 

This is my splitter set up and the tool box covers up everything.

https://www.dieseltruckresource.com/...cat/500/page/1


https://www.dieseltruckresource.com/...cat/500/page/2


https://www.dieseltruckresource.com/...cat/500/page/3

 

You can get mandrel bent tubing from stahl hearers. Thats where I got mine to do my exhaust. It's pricy though.

 

wannadiesel ive seen that done before. how does that work? do you split in and run tubing to each stack or what?

 

I'm just going to plate over the ends of the square tube so it's a big box, then weld a pipe into the bottom for the exhaust to come in, and two into the top for the exhaust to come out. The exhaust just goes in the box and comes out the stacks, no internal plumbing, the box is the plumbing. The reasons I'm doing it this way are: 1) I'm getting the scrap steel free. The whole setup is going to cost less than $150 as opposed to around $400 if I had to do it all with exhaust tubing. 2) I expect the giant box to act as a resonator and make the exhaust note deeper, more like a big rig. Maybe I'm wrong, but it's still cheap.

 

Wannadiesel, your idea will work fine, keep in mind that on the inlet flange to the box or stack header that you must have a divider for the 50/50 split so the stacks will smoke the same, if you dont do this than the passenger side stack will do 80% of the smoking.........................easy way to do this is to put a 1/8" plate inside your 4" inlet flange the extends completly thru the round pipe flange and into your square box/header, I hope I explained this OK

Cheers, Kevin

 

So the exhaust will go in to the box and just have to find it own way out. thats a good idea, but will you lose your smoke? Because thats the one think my truck does is throw out some smoke. and id like it to be as even as possible, commin out of the stacks.

 

No, the smoke will still come pouring out, it's got nowhere else to go. I can't see any reason it wouldn't come out of both stacks equally, the inlet is only about 4" off center. It's not like it's lined up with one stack and not the other.

Ever seen an asphalt dump truck with the exhaust routed through the bed to keep the asphalt hot? They still put smoke out the outlet at the right rear upper corner, and that's a lot more volume than my splitter box.

I should have it put together within a month or so, I'll let you know how it goes.

 

I want to make sure this is clear so you will have to only do it once................I am callint this box you are going to make a stack header, now on this stack header you will have a 4" round flange for the pipe to hookup to from the turbo, this round flange MUST have a split right domn the middle to even out the flow 50/50 so the stack are equal, now this split muct also be done in the stack header box too, the stack header box can be one piece but this plate must totally seperate the stacks............If you have ever seen a splitter "Y" for stacks then you will get the drift, I will try to locate a pic later

Cheers, Kevin