2.5/3.2 exhaust diameter

[The Radium King]

hi. i'm looking for inside diameter on the exhaust manifold where it connects to the mid-pipes. hoping to compare size from a 2.5 to a 3.2. i think that the 3.2 is 1-7/8, and that it is the same as the 2.5, but am uncertain.

[JAAY]

I believe their both the same. The only thing I know is that the S muffler itself flows better than a 2.5 muffler. I did not due the research on that but someone else has.

[The Radium King]

that's what i was thinking. if so, if a person wants to do an inexpensive cat delete on their car but has issues with the quality of the cheap ebay headers, then using the manifolds from a 2.5 is a good option; compared to the 2.7/3.2 headers they will will flow better, be lighter, are inexpensive and higher quality than the $69 ebay offering.

if they are the same ID.

[BYprodriver]

Originally Posted by The Radium King

hi. i'm looking for inside diameter on the exhaust manifold where it connects to the mid-pipes. hoping to compare size from a 2.5 to a 3.2. i think that the 3.2 is 1-7/8, and that it is the same as the 2.5, but am uncertain.

The 2.5 is smaller as it should be, I don't have any to measure but that is the reason the gaskets are different.

[The Radium King]

so, perhaps the primaries are smaller on the 2.5 but the secondaries are the same as the 3.2?

one thing to note is that some ROW markets don't have cats on the headers of the 3.2 (ie, australia, germany) and the headers they use look suspiciaously like the 2.5 headers. here are some comparative images:



and



one is for a 2.5, one is for a german 3.2. differences?

[jaykay]

I think you are on the right track moving the cats out of the headers would improve flow. Put the cats in the mid pipes for a straight shot through. I would look into buying 3.2 take offs on a German site. I sniff around FVD once in a while.

I can measure the entrance to the 2000 3.2 secondary cats if you still need it...I have fabspeeds so I dropped them