Can anyone assist the OP with this issue?:thumbsup

 

i was asking the same thing a while back but after ages of searching i found another forum saying it is 2.5 but not checked it yet

 

I think the O/D is 2.5"

Get underneath and and have a measure..

 

thanks chaps

 

if you want to know the diameter but only have a means of measuring the circumference, divide the value of the circumference by pi (or 3.141) and you'll get the diameter :thumbsup [sorry if you knew that already]

 

2.5 sounds a bit too big? Iv just had a full system installed on my 328 and had both pipes from the manifolds back replaced for 2.25. I think they are more likely to be 1.75 or 2 inch pipes.

 

320s have a larger single pipe, and 325s and above use 2 smaller pipes.

From my experience, the 320 is one of the best sounding BMW engines without even trying.

 

Ahh cool, learn something new everyday :-D