Good work Greg..

[William Northrup]

  The header design you spoke of is a very good design. There are easy
ways and lazy ways to kinda accomplish the same thing but they will
never reach that potential. I had a set try y's on my street Mustang that
worked and sounded awesome. As my Mustang grew into the full race
(road race) mode my needs changed. I built a set of custom try's (not a
set of fancy under the pan types) with oversized tubing. The oversized
tubing was used to soften jagged torque peaking. When you are in a long
right-hand sweeper at 120mph in oversteer, the sudden application of
torque is a bad thing. These headers teamed up with a merge in the
tertiary pipes works very well. The merge was accomplished by cutting
off the outside 1/2 off of two 3 inch 90's and welding them together in an
x or )( fashion. At about 6000 RPM this setup would develop a beautiful
Indy car like whine through 7500 RPM. Check out the next NASCAR
restrictor plate race. Look carefully at the exhaust system as they fly
through the air and you will see what I am talking about. 

Greg can you please elaborate more on that resonance/expansion
chamber you were talking about? Thanks!