How hard would it be to make a couple of CAT stacks out of 4" diameter aluminum? I have access to a bunch of cheap, if not free, 4" irrigation pipe that's all busted and bent up and I thought about using to make a set of dual stacks for my truck. I can go in and ask my AG Fab teacher from high school if he can weld the pieces together for me. I found this picture and I want the 45* setup. Also, what do you guys think of running dual CAT stacks? I know they are normally a single setup but thought 2 might look neat. Are the angles 22.5* to get the 45* bend then a 45* cut to get the flat tip of the stack?

 

this sounds like a lot of time and effort to try to piece something together, which would most likely result in leaks, imho. i went to a local shop (pueblo brake and clutch) and could get everything other than the stacks for under 200 bucks, including clamps and everything other than the actual stack itself

 

Its not like I'm welding inches of straight pipe together to get a 3 foot stack. This irrigation pipe has some straight sections to it(I've helped move it before it got bent or broke) and I would cut a good 5' out, cut the angles and weld the 2 pieces together. I've got everything but some flex pipe which I can get at a parts store for less than $8 in the size I need and the clamps to clamp the aluminum pipe to steel and to clamp the flex pipe in. I have a 5' steel 2x6 for my "y pipe", all I need is a couple of stacks. I'm running a single stack now but want duals. If its too much of a PITA, I'll just miter cut them and call it good. Just wanting something different.

 

Will aluminum work for exhaust?

 

I've read about it. I don't remember whether it was on here or another forum but I read about a guy that made the stacks and y pipe out of aluminum. It sounded a little different but I think that was mostly from the "y pipe" being aluminum too. The pipe I plan on using is the ball and socket type, for those of you familiar with irrigation pipe, so its used to expanded and contracting with the water pressure. I don't really see why it wouldn't work. The melting point of aluminum is 1220* F and by the time the exhaust gas hits the stacks, it shouldn't be that hot anymore.

 

I dont see why it wouldn't work, there's no pressure on it and the exhaust gas wouldn't be hot enough back there to melt it, I wouldn't think. Probably the hardest part would be making sure you get all your cuts and lengths exactly the same, so they match, but that shouldn't be too bad

 

You have a very valid point. I would say go for it then. I have planned on making me a cat style stack for my truck doin the same thing but with aluminzed steel pipe for awhile and just havent got aroudn to it

 

I say go for it. I like unique mods done to the truck. And you cannot get a greater satisfaction than doing the work yourself.

 

I'd like it a lot more if I could weld the aluminum. Maybe I'll get the chance to learn with this. I've decided I'm definitely going to do it, just having a hard time finding sections of pipe that don't have any dents in them.

 

Make sure to post up some pics when you're done! It sounds like a fun project if it turns out how you wanted... then you could always polish the aluminum to a nice shine