I've seen some headers recently with some design features that may be gimmicky, but I'm not sure. One of the features is a "stepped primary", where the primaries go from smaller to larger. I don't know why this would be a good this, but supposedly it increases the velocity of the exhaust gases. The other feature is an "equalization chamber", which is a tube which goes between the secondaries. I don't know why this would be good either, but supposedly it is good for high-rpm power. Does anyone have any real world experience with these types of headers? I know I haven't seen this stuff on the higher end Honda headers before, but maybe some domestic guys have heard of these designs.

 

The stepped primaries are not a gimmick. They are designed to balance the goal of keeping the exhaust velocity high, while not prividing too big of a restriction as the gas expands. The steps also provide some anti-reversion properties.

I've only seen the cros-over pipes on domestic V engines, to join the two sets of secodnaries from each bank. I would think that, they would do nothing for an in-line engine.

Mike

 

Thanks for the input. I just wondered why I didn't see stepped primaries on DC's stuff or most anyone's stuff, actually. The only headers I have seen with these features are made by companies that were traditionally affiliated with domestic aftermarket power. Anyone else?

 

No one else has input on the equalization tube?