x and h pipes
To keep things simple, if you have anything stock or relatively mild and are simply wanting to upgrade or go to a dual exhaust, run an h-pipe. With the X coming on strong, prices have dropped for the h-pipes, and if nothing else h's are easily fabbed up by your local muffler house. The price will stay within your budget and you should be pleased with the results...
If you have built a high performance motor or are looking to get the most out of your ride, run the x-pipe.
I have been trying for several months to find definitive data on whether the "cutout" in an x-pipe system is better off being placed before the "x" (more in line with the collector) or beyond the "x" (take adv of improved scavenging). This is essentially a jegs/summit design versus the pypes design...No one seems to have et, mph, etc, much less flow numbers.
The 1st hand feedback I have received was simply most guys running the x with cutouts, made runs in all the three configurations: 1-open headers (no exhaust), 2-thru the entire exhaust, and 3-thru the exhaust out the ''cutouts."
The feedback I got was that there was no gain et/mph in either set up...If you have an x-pipe that can match #s with open headers at the track, something is going right. I would venture to guess that an ideal h-pipe for the same car would be a tenth or two slower.
As I have said, if your goal is simply a dual exhaust for your daily driver or cruiser, go with the h pipe....If you are looking for the best all out set up, go with the x. Both layouts equalize pressure, but the 'x' will win out in terms of scavenging, hence the gain. The 'x' will also tone things down a tad more than the 'h' pipe. This 'toning down' is largely influenced by the singular application and the muffler you have selected.
Muffler choice is a personal issue as everyone's preference to tones, resonance, dbs, and flow are variable. One guy just wants to sound good and could care less about flow, the next guy wants no sound with all the flow, and the next guy wants the best flow #s with the nastiest sound. Don't forget the guy who wants the loudest car in town, but also insists on no interior resonance, lol...
Also to consider is your pipe size, floor pan clearance, inlet/outlet location, side or rear exit etc...all of it has to be taken into account.
Similarly, many people still seem to take foregranted the impact of the cam/heads/valvetrain on the "sound" of the car...I still see people dissapointed when their flowmasters don't make their car sound like a high lift, long duration cam :toothy10: Live and learn I suppose, lol...
You really need to just size the pipe to your CID and HP levels for optimal gains...In other words don't choke your 318 down with 1 3/4" pea shooters or something...Just be smart and effecient, not a total penny pincher. When done right you will have something to be quite happy with and not out a lot of $$$.
I could keep going, but the point I'm trying to make is simply take time and research your application...Guys have sound clips all over the net are more than willing to share.