DIY Exhaust
 

The P.O. of my SD "redid" the exhaust, but did a terrible job. I am thinking of trying to re-do it myself. The downpipe and the bent pipe along the underbody which follows directly after are fine, but the rest is a weird concoction which terminates at a muffler before it even gets to the rear axles. The whole thing is held up by plumbing straps and wires in random places along the underbody. The muffler is hanging about 4-5" above the ground where it ends due to being too close to the rear floor pans and rubbing against them if it is raised up any higher (causing obnoxious rattling inside).

I am thinking of just running a straight pipe or reusing the muffler he used, but I have no idea how an exhaust system is usually installed. Is it possible to do DIY exhaust without welding or bending pipes? The PO used lengths of pipe that bolt together with U shaped bolts about every 2 feet. I was thinking of doing the same but doing a better job of suspending it and bringing it all the way to the back of the car.

If I remember right, I only seem to remember seeing one exhaust hanger bracket thingie underneath the car.

Has anyone done a DIY exhaust on one of these cars that can provide me some pointers?

The OEM exhaust system on an SD has two resonators, they look like pods with a split pipe going into each side, they are located in front of the rear wheels, the exhaust then exits those, turns back into a single pipe, goes into a big straight-through muffler pot, and then out the back with a twin pipe exit.

I just used a straight pipe from engine to rear...fairly loud when accelerating with the windows down, but barely a detectible difference with the windows up from inside the car. At idle or when coasting its perfectly quiet, also pretty quiet on the freeway. Cheap too. I had the shop use 2.5" pipe which I then painted black with high-temp paint to prevent rust, works great.

That sounds like the kind of thing I am thinking of. How did you suspend your straight pipe?

It is connected to the car only at the turbo, the clamp on the side of the transmission where it comes out under the car, and at the very back with two little "arms" off the pipe (welded to it) that reach to the hooks the original rear muffler hung from. Two little rubber donuts complete the suspension to the two hooks. No vibrations, and its very solid. 2.5" pipe is very strong!

Hmmm... I'll have to take another look, but I don't think I have the clamp by the trans (or do you just mean where it clamps to the downpipe?), and I think I only have one of the hooks in the rear.

So your pipe must have been bent by a shop to follow the path of the original exhaust, is that right?

I had my SD exhaust system redone, it was $$$. The flex pipe, down and back is straight to the muffler. The resoanators had the rubber dough nuts on 'em, way out to the sides. I had the fella mount a straight rod, bent at the proper places, welded to the pipe, and hung the dough nuts there, all's well.
It's a long way to the muffler, I'm more comfortable with the extra hangers ahead of the axle.

Yeah, where it clamps to the downpipe. The shop bent it to follow a path pretty close to the original. Looks and functions excellent. There should be two hooks across from each other at the very back of the car....if one is missing maybe it rusted off? :eek:

The pipe will have a tendency to twist if only supported at the front and rear due to the bend. I found this out the hard way.

The stock exhaust is supported in such a way that the torque(ing) cannot take place. The two hangers in the center spread apart almost the width of the car.

That won't happen if you have one-piece solid pipe or weld that joint together! :D