I just dont have the money for a kit right now...Not even close lol. I Googled it and saw so many people doing it with the 2x6. But i hear you on the exhaust flow.

 

One of the Knuckledraggers(crew cheifs for you guys) when I was stationed in florida had the 6x6 square tube. A 90* through the bed into the pipe, then the stacks were mounted onto the tube. It looked good but did take up some room. Flowed pretty well though.

 

Kris, you can get the bends and make the Y pipe yourself out of pipe just as good as most stack kits are. Just make sure that you put a diverter in the Y to evenly split the exhaust between the 2 stacks.

 

My kit is home made

 

YouTube - Pypes Exhaust 12" Diesel Smoke Stacks

saw a guy with these a few weeks ago strokin along. He stopped for a red light and when he pulled away the ENTIRE sky went black! When I saw him at the mall later on I asked him about the 12 inchers, and he directed me to PypesExhaust!

 

haha that is the worst thing i have ever seen..

 

never thought i would say this , but thats to big!!! from what i have seen in my opinon, any thing over 6 is a wast of time and money, just my 2 cents!!! stacks that big is for a guy with little man sendrum! lol

 

I have homemade stacks with 6x6x.25 running the width of the bed just like you are talking about and it sounds great and flows really well and you still have the wistle of the turbo. Its super heavy, like 180lbs but I got it for cheap...total price of stacks was $50 and thats including SS uprights. If you want I can get pics this weekend when I go home from college.
But i wouldn't run 2x6, because your surface area is 12 in^2 and round 5" tubing would have a surface area of 19.63 in^2 so you would have a reduction of 38% of flow area. So you would need to run no less than 3.25x6" tubing to have the same flow as the 5" tubing

 

yeah man pics are the best around here!! like them trac bar's to man

 

Pics would be awesome! Ive been seeing a ton of the 2x6 with 1/4 inch wall. But that its been said, i dont think it will flow right.

 

I did some very basic calculation above and you need to run no less than 3.25x6" to flow the same as a 5" exhuast tubing

 

dude seen a dodge to day with 6.5 tuding and it ran just like your thinking, but he used same on the stacks but turned them like a dimand and slashed cut them, it looked and sounded bad @ss, you no for a dodgeand all

 

Flow is much more than surface calculations. I am no engineer so I don't have numbers for you but the dead end "bends" is the biggest factor in that type of in bed pipe not flowing well.

 

Tim is for sure right, any square turn is going to adversely affect the air flow. You never want any dead ends like a square will give you on any air flow. Just put a picture in your head, air flowing nice thru a 5 inch straight pipe till it hits a sharp corner, then deflects, and is trying to go every direction. With a rounded corner, it just flows around the corner and out, not disrupting the air flow at all.

On edit: It may be easier to picture water in your head instead of air running, but you get my point.

 

That's very true Tim. I haven't dealt with fluid mechanics much since college, although it doesn't take a rocket scientist to reason through the dead end causing a much higher turbulence (Reynolds number) and decrease your flow velocity. The sharp angles in the tubing itself are also not ideal for flows of any fluids, as stresses will build on you 90º angles also taking away from your overall velocity. Even with 45ºs welded into the corners would not be ideal, as the pressure would still build in those areas. Smooth radius's are the way to go

EDIT: Darin can type faster than me haha