So what do you guys think? I'm planning on a 5" turnout single stack. Also with 4" from the turbo back. Down the road I want to do twins so I will put a flange under the truck that way I only have to replace a small front section when the twins go in, (after the tranny) Any one with singles? -bob

 

start at the stack and go back...

I would go under the frame rail so that you can fit the 5" pipe without any trouble, and the bends will be smoother... then just point it towards the downpipe and put a 5" ID - 4" OD connector on it... build your 4" downpipe, and connect the two with a length of 4" corrugated flex.

then when you do twins, just remove the 5-4 reducer and run 5" flex between your 5" downpipe and the pipe leading to the stack.

for some reason, some people say not to use flex... I love it... every big truck on earth uses it, it makes up for slight misalignments, and it keeps stuff from cracking.

I like it because you can quickly/easily break down the exhaust and even swap between straight pipe and muffled... unbolt the band clamps (use torca lap-band clamps!!) slide the flex forward (or backward... be sure to leave a decent length of 4" pipe either on the downpipe or back pipe to allow you to slide the flex 3-5") anyhow, slide it, pull it down a little to clear the other end, and slide it off.

Forrest

 

1' of flex = 10' smooth pipe worth of backpressure.

 

10' of smooth pipe must not have much backpressure!

Forrest

 

ok, I just searched all over the internet for some sort of factual data to support that claim... NOTHING...

I certainly couldn't tell a difference...

I call BS on it hurting performance untill it's proven otherwise...

Forrest

 

Anyone have pics of a 2nd gen dually with single stack? I am planning for the future, and I can't make up my mind on which stack setup to use. Not wanting to hijack the thread, but I find the different styles amazing.

 

Josh,

I like a turnout or curved top stack for a single... maybe a flat top w/ a rain cap, but for some reason I think miters only look good as dual stacks... heck, even just a regular flat top, but not a miter...

but I prefer the turnout/curved. you can experament with facing it in different directions for looks/sound, and the stacks that exit up make the truck quieter to passers by, and we wouldn't want that, now would we?!?!

 

I have one with a single stack, look at my album. I have more pictures of underneath it if you need them....

 

"Single stack Mack with a picture window in the back..."