That was a for an NA motor though, dunno if it's as important for turbos as the manifold is pressurized.

do you mean something like this

http://www.imagestation.com/picture/sraid50/p3a18c6f1c52d0a2a7d5e4f08616522a6/fcaa9f1a.jpg

http://www.imagestation.com/picture/sraid50/pdd959a9f5c6fbad30e79bb6a5a8c7817/fcaa9f1b.jpg

http://www.imagestation.com/picture/sraid50/pb221eac97ebdbded26f898bcb5184b0e/fcaa9f19.jpg

yup, pretty much! Except my friends had it more like a half cylinder than a box section. And I think the taper started closer to the TB. And those are the trumpets I was talking about at the top of the runners into the plenum. My friends made three prototypes of runner entrances: 90 degree, radiused, and trumpted. They had already simulated them using CFD but they proved it out with the prototypes and a flowbench. The trumpts had the lowest pressure drop=better flow.

Were those models done in Pro/E? looks kinda like it.

no, they were made in Cobalt

i think you runners are to long id shorten them up a little

Im gonna do some searching :D

Air horns have the best flow... because when the air comes to them, it speeds up to go over the horn.. That makes it stick to the walls and therefore results in smoother flow. Just regular radiused edges make for good flow... but it tends to create turbulence in the runner as comes into the opening. The turbulence is from the air swirling down into the runner. On N/A motors.. horns are more critical.. on FI motors... it's realy not that critical between the two.

I dont like to bring back old posts but what happend to the polk intake manifold? Is it going to be built and sold to the public?

Actually... after being buried for a while.. We have something in the works to build an intake manifold for the highport motor right now.

Could you please keep us posted?