anyone know? NA S4...?

 

WTF sum1s gotta know!

 

Uhh like 2.5" or so.

 

I've always wanted to know this too... Inner Diameter... not outer

 

yeah inner...and i dont think it's 2.5"

maybe 1.5-1.75" but i dont think its 2"

 

Oh, right. 1.75". I'm almost sure maybe, possibly, perhaps.

But I'm definitely maybe not yes I am almost sure.

Oh yeah...cause the racing beat replacement is 2" or 2.5". It's 2. I think.

But the stock might be 1.75. I'm getting more confident that it's 1.75. Am I helping?

 

im staring to believe, i went under my car to measuere and it looked like 1.75" but im still not sure.. anyone got official numbers?