If i get a 70mm test pipe and exhaust? do i need to mate up a header with a 70 mm collector
if I plan on getting a 70mm test pipe and exhaust, I would want a header that matches that, correct? Correct me if I am wrong, but my understand was it was always best to have the same size piping through from header back.

Thanks

 

Sure it would be nice to have a 70mm collector to mate with the 70mm test pipe BUT i have a 70mm test pipe mated to stock header and stock catback no isssues.

 

so it can be mated with a smaller header size?
is really what i am asking cause i am not sure how it would fit i am a newb when it comes to this

 

The largest collector for a header I've seen is 2.5in or 65mm. It's fine to run a smaller collector to bigger piping since it wont bottle neck just don't run larger piping to smaller.

 

There are no headers out with a 70mm collector.