This winter I will be finally doing my UK Exhaust Mod. I decided to go for 44mm ormaybe 38mm. My only problem is:

I am not sure if you people name the outside diameter or the inside diameter?!

The outside diameter makes absolutely no sense without knowing how thick the piping walls are.
So when ever someone says 38mm or 44mm.. are those the inside diameters?

THanks !

 

I did mine w 2" piping (50.8mm) and I wouldn't do anything smaller than that, it sounds great.

 

2" piping... nice... outside diameter or inside diameter?

Naming the outside diameter without the wall strength of the pipe is a useless information. I can get a 2" piping with 0.5" thick walls which means the inside will only be 1".

 

1/2" thick pipe FTW

 

Could also go with 1" and then the inside diameter is zero

A guy on youtube made a video for a 44mm UK mod.. turns out this is the outside diameter on his video. So I guess the inside diameter would 38mm?

 

Its almost moot if its id or od. The wall thickness on exhaust pipe isn't going to make that much difference.

The difference between, say, 44mm id and 44 mm od is the id of 44 m od is going to be like 41 mm. Not really going to make that much difference in sound for UK mod.

 

ID. If it was OD then the actual flow capacity could be anything due to material thickness.

 

Exactly my thinking but as you can see above, most people actually mit OD or don't think it matters.

 

Because its exhaust pipe, not any old pipe you might find. No one is using cast iron pipe for this mod. Exhaust pipe has a typical wall thickness of .0625 inches. Do the math, its not going to have a big effect.

Most people had an exhaust shop do the mod, and used pipe supplied by shop. So they just don't know if it was id or od.

 

People are arguin between 38mm and 44mm which is a 6mm difference when not knowing the 3mm variable that the wall thickness is.

In any case.. I will probably take 43mm (OD) with 1,5mm wall thickness which ends up with 40mm ID.. probably a good compromise between the 38mm and 44mm version.