im planning on building a header for my s4 n/a 13b and im looking to get some information on different header lengths. i DID try searching but all i found was vague guidlines and people's opinions.

anyways, i understand that there are two options for the length of the primaries: long and short. im wondering if anyone can post a link or share some knowledge as to the ideal length of the primaries for a stock ported engine, and the pros/cons of short versus long setup. thanks for your time guys.

 

This is what I've gathered about collected headers for the NA engines.

-Short More high end, less low end torque
-Long, More low end torque, less high end hp.

Thats at least what I remember. Your not going to find any 'facts' here btw, this is a forum, and all it is, is a huge collection of peoples opinions. If you want facts, read a book.

 

ok, i guess i am looking for opinions. is there a general length people here accept as "ideal" for the short setup? so far ive seen 18"-22"(racing beat header?) and 24". any dyno charts of different headers maybe?