You want to mount the stack to the bed. If not it will flop around like a limp dick. Since you want your truck to articulate I recommend using a short piece of flex in your setup somewhere. It could be before or after the 90 degree bend. My personal preference is to have it before the bend, but its not a requirement.

 

I just ran a 90* up into the bed. no flex pipe for me... but i think it would have been easier if i would have.

 

Ok, so the easiest way to install and allow for enough flex from the frame/body would be just put a small piece of flex right before the 90* and then just mount the stack to the bed inside, correct? And thanks for the help guys! Seems like its about how i pictured it then, and should be a pretty easy install.

 

I think you got it :ford:

 

Weld a plate to the bottom and bolt it to the bed!!! No clamps!! Do it clean though...

 

Pics? Im a little slow... LOL and yea, im wanting a clean look.

 

The only pics I know of are mattgw86's... no offense to him, but I wouldn't do it exactly like that...

I'd mount the plate on the bottom of the bed and make sure either my welds were hidden, or very clean/ground flush...

 

Boggerr... I said that...
oke:
J/M

 

And you could use washers to align it if it wasn't perfectly straight...

 

To make it a nice clean look.I would put the stack up through the bottom of the bed that way the plate is mounted under the bed and use some carriage bolts.

 

what size stack is that? 36"?

 

Yeah. I was thinking about using this SAME EXACT stack... it's from the other side of slowleak's duals, but I'd have to hid where it necks down... luckily I have an old in-bed, flush-mount, toolbox to use!

 

Mine is 12" of flex pipe, 4" 90*, 4"-5" adapter, then the 5" neck on the stack which is a 6" x 48".

 

read above you Jap

 

not one bit. that was my biggest worry when i realized the bottom plate wasnt gonna fit. when i say that thing was solid, it was solid. now in my truck, i accidentally chopped that bed support that runs across the front of the bed, which weakened the bed a little, so it kinda has some movement in it, but it is the bed itself that is moving, not the plate/stack.

i have some more ideas i will be working on this week, with a under the bed plate. just taking my time fabbing it.

 

oh yeah and i will be re-welding that rail:doh:

 

I'll make mine fit underneath... you just have to think ahead Dug... oke: LOL j/k

 

it will fit, with a good bit of pre-planning

the day i built it for matt we were in a rush. the day i built mine i was just bored and wanted to play with the new saw i bought:doh:

give me a couple days and something really cool will be built:evil

 

heres a quick pic. excuse the mess, havent had time to cleanLOL

 

The easiest way to do this and cleanest way IMO is the following:

Get an 8"x8" plate. Cut a 4" hole in the middle of it. Weld a 4" piece of exhaust so that it protrudes an inch above the plate and at least 3-4" below the plate. Weld your stack to the plate. Cut 4" hole in bed, insert stack. Drill 2-3 holes equi-distant from each other and bolt it in. Underneath, cut your exhaust, run a 90* up to your stack and clamp it. Done, it won't rattle/vibrate/move/etc... and to take it out is one clamp underneath and 2/3 bolts.

 

The plate idea is one I have always planned to do if I ever ended up putting a stack on my truck.

The only difference is that I had planned to weld a short section of tube to the plate that would protrude past the bed surface, and then slide the stack pipe down over that piece and put one of the two-bolt band clamps there. That handles any alignment issues easily. Just square it up well, and then tighten the band clamp.

Then on the bottom side have a piece of tube the diameter of the pipe under the truck (probably 4"), from which another clamp (V-band preferably) can be used to attach the assembly to the rest of the exhaust.

This way the plate serves as the mount as well as the transistion from 4 to 5 or 4 to 6 or whatever the case may be. If the variance between sizes was large, you could substitute a 15* transistion welded to the bottom of the stack in place of the straight pipe. That would smooth the flow into the stack pipe.



I also advocate the use of a rain bell under the truck. Once the exhaust pipe gets back to horizontal heading back toward the engine, have a transition from 4 to 5, and weld about a 6" section of straight 5" pipe to the end of the transition. Then slip the 4" from the engine down into this so that it nearly meets with the end of the 6" section of 5" pipe back inside where it's welded to the 4 to 5 transition. If you took some 3/16" x 1" (or similar) flat bar, and welded it to connect the 5" section to the 4" feeding into it (so they cannot clink and clang together) at say 120* intervals (thirds) then you'd be all set.

And when it rained the water would just run right out freely. Yet you wouldn't have exhaust leaks.

 

The plate idea is one I have always planned to do if I ever ended up putting a stack on my truck.

The only difference is that I had planned to weld a short section of tube to the plate that would protrude past the bed surface, and then slide the stack pipe down over that piece and put one of the two-bolt band clamps there. That handles any alignment issues easily. Just square it up well, and then tighten the band clamp.

Then on the bottom side have a piece of tube the diameter of the pipe under the truck (probably 4"), from which another clamp (V-band preferably) can be used to attach the assembly to the rest of the exhaust.

This way the plate serves as the mount as well as the transistion from 4 to 5 or 4 to 6 or whatever the case may be.

Would that produce better dyno numbers or quicker ET

 

both, venturi effect in the exhaust makes more usable HP