Paul

Does anyone out there have a picture of the six port arrangement under
the manifold?  All I can find on the web is the four port.  Are the four
outer ports all the same size or are the lower auxiliary ones smaller,
and if so what are each of the sizes?  In the picture of the previously
posted cut down manifold it looks like the upper ports are much bigger
than the bottom ones.

Tony Beaton

the large round top holes in the end housing is the reason the
RX8 high power engine can generated 240 HP.

Paul Lamar

Thanks for the picture, a big help.  The reason I asked, it struck me after
reading your comments on "6pipes vers 2pipes", when I was at the YAW POWER
site where they show the Renesis being mounted on the dyno (see photo top
right), that Mazda grouped the Center port and Aux. port on a common runner.
Now my thought is, that looking at the picture of the cut down manifold all
6 pipes are 30MM, which does not compute with the two larger ports.  Now if
two could be grouped into say a 40MM runner(area of 30MM x 2 = 40MM x 1
+/-), my thought is blend the 4 center pipes into two 40MM and feed in two
single 40MM to the two outside ports which should be larger anyway
facilitating surface area drag equal to the six but with more flow at high
RPMs or = to about 7 x 30MM or 17% more flow.

30MM = 1.094 sq in area x 7 = 7.658 sq in
40MM = 1.948 sq in area x 4 = 7.792 sq in

The cut down manifold could still be used as a mounting flange.

Tony Beaton