Right now, the stock exhaust pipe is pretty small, and, like others have done, I'd like to go a little bigger - like 2.0 inches. Problem is, can I use a "reducer" pipe, and turn it around, so it is actually a "diffuser" (to go from small dia. to bigger dia.). And second of all, can I make this? Thanks,

Stephen

 

Being that you neglected to tell us what year, model,engine and exhaust type you are planning all this exhaust work on, answers are going to be vague. If you need a pipe adapter, try a muffler shop. They have pipe expanders that would seem to fit your requirements.
Jim

 

Why not just get new pipe bent and have the shop do it all.

 

Dang, where does my sig keep going...

Okay, so the "pipe expander" does exist....that's all I needed to know - if there was such a thing, or if I could do that.

edit: oh - "Always attach sig in post"

 

Check out your local auto parts store. I know at least my local "Advance Auto Parts" keeps a variety of exhaust bits and pieces. A 1 3/4" to 2" adapter (or whatever) should be right there on the exhaust aisle. Also the clamps to put it on. A pipeexpander is nice to have but fairly pricy, such an adapter/reducer can be had for around three dollars.

 

clamps? What about welding?

Thanks for the suggestion - I will check em out

 

Adapters/reducers are too short for clamping to be reliable, and they aren't slotted at the ends so that a clamp can squeeze them tight anyway. So plan on welding.

Unless you absolutely need to butt-weld it to get the very most out of it (which would be overkill for a 6-cyl exhaust), an adapter should fit over the pipe in front of it and inside the pipe behind it. IOW, the ID of one end of the reducer should match the OD of the pipe up front and the OD of the other end of the reducer should match the ID of the rear pipe. Pipe ID is normally 1/8" less than its advertised OD. If you're specifically adapting 1 3/4" pipe up to 2" pipe, a short length of 1 7/8" pipe would work if you can find it.

Norm