header merge angles

[tharptroy]

I've done some searching through previous posts on this, and havent really found any answers, but I apologise if this has been covered.

im toying with the idea of making my own header for a car of mine.

its a 4 valve/cyl head, 93.5mm stroke and 82mm bore. and currently, peak horsepower occurs at around 6,000rpm. (street car)

not that thats really relevant. im looking into using the dos version of the maxracesoftware's "pipe max" to get me in the ballpark for the right sizes.

here's what im wondering...how critical is the merge angle of two primaries (or secondaries)?

also I see alot of 4-1 collectors with a blunt point in the center, this seems like its going to create turbulence, and not allow the gasses to easily "merge" into one stream.

and I also see alot of sharp angles on cheap headers.

sometimes I'll see two pipes that look like they converge upon one another at different angles, which sureley cant be what you want.

I guess, what are the critical areas that I should be really looking at when it comes time to build my header?

EDIT: I made a post that really shows specific things im talking about, but the pictures are hosted by that forum, so you'd need to register there to see what I was talking about.
here's the thread http://www.elantraxd.com/forums/showthread.php?t=9479

I would SINCERELY appreciate it if someone could correct/evaluate/advise me on that post, since im sort of a "guru" on those forums, there isnt really anyone to chime in and give me advise there.
Thanks!
-Troy