Paul:

Re: Long tube intake runs made to behave as any length one wants!!

Back in the dark ages of big displacement Mustangs at FoMoCo when I was a Product Engineer there, we got surprisingly improved HP results by putting into the dual exhaust system what is now known as
the "H" portion of the dual exhaust pipes.  That is the FL and RH pipes are connected with a cross pipe.  It is a "tuning" measure.  It complicated the installation of the system having to miss the
tranny and other cables, linkages, etc.., made the system more expensive, and created NVH issues for sound guys, but the HP was not to be denied.  Note: It also made the sound much smoother and less
harsh!!

In order to tune a pipe, the dimension of interest is the length to the first major area change.  In this case the location of the "H" pipe functioned to tune the exhaust system to a particular
rpm.  Recently I have observed on local "muffler" required SCCA racing systems that the duals smoothly curve inward next to each other where they touch....and where holes into each system have been
made....and then they are welded around this oval (as viewed from the side).  Makes one scratch ones head that it would work, but the results and enthusiasm of the users seem to prove the benefits.
Seems to me to be the same technology as we used back then.

My thought is that the "long" intake pipes which are already close together could be joined at the proper "effective" lenght with either a small connector pipe or curved in then out, holes machined
in the touching sides of both and then welded around the periphery of the "holes"!!  My NVH experience says this should work.

Has anyone tried it??

Doug Dempsey

It does indeed work and you are describing an RX8 intake to a "tee" pardon
the pun if any. The problem is the Q is lower. It tends to broad band the system at
the expense of peak power. A true infinitely variable system will have peak power
at any length and RPM the pipes are set too.

Paul Lamar
 
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