[EMKOOP]

Originally Posted by FD3S

According to the Superspint website the below two are the available headers for the Z4M:

1) http://www.supersprint.com/ww-en/bmw...-drive.aspx#!/

2) http://www.supersprint.com/ww-en/bmw...-drive.aspx#!/

Do you know which is the stepped SSV1?

Thank you for your help.

If you take a look at the headers themselves you can definitely see the "STEPPED" design (Tubing diameter growing as they lead to section 1 connection).

#044001 is V1 STEPPED
#787501 is V1 REGULAR

All V1 headers will need to be connected to SS section 1s.

V2 headers has flanges to mate up to US/Euro OE section 1s.

#044901 is V2 STEPPED
#043901 is V2 REGULAR