engines fire like so: LRLLRLRR and its those double pulses which are killing you.
In an H configuration, your basically working with two straight pipes since the gasses rarely make a 90 degree turn - especially at high pressure (why the power gain is lost at high RPMs). So when the gas is travelling very quickly, your still running down one pipe
In an x config, those double pulses get a better chance to split up at the x junction. So then its like doubling the net diameter of your system.
In either case, your better off then a single exaust.
h pipe:
- possible backfire on downshift
- cheaper
- less power gain, because the gasses "tumble" which is why you get the next point
- sounds better (more grrrrburble burble burble burble burble pop burble burble)
x pipe:
- more power (at higher RPM range)
- more money
- less ballsey noise becasue gasses travel faster, which is where more power comes from
http://www.carcraft.com/techarticles.../photo_10.html - pictue of h and x compared
http://www.carcraft.com/techarticles...ion/index.html - article about both
these guys got a 12 HP and 5ft-lbs increase with X over the H. I think that an increase of 8 is ambitious for our trucks...
anyhow, nothing can beat this
http://kalecoauto.com/index.php?main...;products_id=3