It is good to read a few nice comments, instead of wrong, wrong, wrong, etc.
Then, ponder this; what good was an H-pipe two decades ago, and now an X-pipe?
In the end, my questions are basically, what downside is there still in an X-pipe, and how can it be bettered? My hint is "think of a header collector." Regards,[/QUOTE
Just my thinking,
H-pipe, to equalize pressure pulses. Then X-pipe comes along to try to do it better by reducing the angle of the cross-over pipe. Of course all of this is due to the un-even firing order of the engine. One pulse can be shorter due to the fact that its exhaust port is closer to the collector because of its location in the head. Hint-collector, OK let me think, remember I've been out of active racing since the eary 70's. We used to take bolt-on collectors that started of long and then would hack-saw off an inch at a time to tune the headers for low end or high end performance. By cutting off the collector this would change the dynamics of the pulses as they come out the end of the collector and meet the atmospheric pressure. This would change the scavenging effect. So with that said, can we improve the X. How about the length of the runners of the X, the angle of the X in relation to the primary pipes and then experiment with pipe diameters in the X pipe itself. Forgot to mention downside. Is it because no matter what it is not as good as open headers?
Am I any where close? Do I even make sense?