Do any of u guys know the collector size of this header? cos sum1 has one for sale bu he says its 2.5" outer dimater but only around 2.25" inned dimater. is this correct?


and what is the collector size of the aussie and US headers?
2" right(inner diameter)?

 

correct

 

odd, i thought the usdm had a 2.25" bottleneck as well?

 

USDM is 2.25 i believe. Might be smaller. The JDM 4-2-1 is noticeably larger than the U.S. version of the header.

 

The USDM and EuroDM/AUSDM header has a 2" (50 mm) OD flange.
All JDM headers incl. the '96 4-2-1 have 65 mm (2.56") OD flange. The OEM ones have a inner tube which 60 mm OD.
Only the B-pipe is 2.25" (57mm) OD except for the bottlenecks.

 

Ok thanks for ur help.

SO what r the differences between a ausdm euro and us header the primary sizes??

 

USDM = cast iron (OD= ?). Euro/AusDM = not cast iron but only 40 mm OD