Exhaust & Muffler Sizes, Inner and Outer Diameters

[dasnoboarder]

Right,

I'm getting some materials together for building my new 2.5" exhaust system, but have some questions.

I'm looking at a straight through bullet type muffler, any opinions on what's best with regard to perforated or louvered cores, and 300mm vs. 450mm length?
For my 2.8L Turbo Diesel.

And, what's the deal with inner and outer diameter sizes!?

- Muffler in/out sizes are in ID.
- Exhaust tube seems to be measured in OD.
- So, the reducer I need for the back of the turbo is 2" ID to 2.5" OD. Which doesn't seem to be available off the shelf.
- No idea how flexi joints are measured...

Anyone had good experience with an exhaust shop in Auckland? Need someone who does good mandrel bends.
A lot of trials trucks had Papakura Mufflers signage, but could be too far to travel from north Auckland...

Oh dear...
Andy

[geeves]

perforated will still be a little loud even in the longer length. It may pass the wof test but the droning on long trips can be a bit much. Most exhaust shops make adapters as they go. If you are getting them to weld it all up let them sort out the pipe