I am going to put my DC JDM 4-1 header on my car soon, I am not going to buy a new 2.5" cat. So what I am going to do is get a reducer put on my stock cat, so the header will bolt up. My question is, is the header length the same as the stock header length? Basically I want to know if they are going to have to modify the lengths of the cat and or the header to get it to work. Thx

 

now what motor do u have and in what car and what model of dc 4-1 header do u plan on using??? then we can prolly help u out...

 

is that a new header from dc? never heard of a jdm 40-1

 

yeah it ads 50 horsepower!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Thrillhouse &raquo;</TD></TR><TR><TD CLASS="quote">I am going to put my DC JDM 4-1 header on my car soon, I am not going to buy a new 2.5" cat. So what I am going to do is get a reducer put on my stock cat, so the header will bolt up.</TD></TR></TABLE>

I'd suggest trading for a "USDM"-style header and saving the cost and time. The primaries are exactly the same diameter on the standard and JDM DC headers, and bottle-necking the JDM header into the pitifully small stock cat basically defeats the purpose and limits the benefits of the larger collector.

 

Its a 99 ls teg with B18B