Here we go again...
In order to maximize the efficiency of the intake, a custom throttle body adapter plate will be made to exactly match the runner geometry. I start with a blank, then cut it to length and face both sides so it ends up at the final thickness:
After lots of chips and with the help of some special endmills, we end up with tapered runners and fully radiused inlets:
Back when I made the Kawi parts, I designed the TB adapter fixture to accept any adapter plates I could possibly come up with, regardless of bore size & spacing. Thus, after clamping the fixture and mounting the part, I'm able to machine the bottom side. BTW, I actually had a custom endmill made to put the little ring around the runners (which gives the silicone connectors something to bite onto).
I'd say it's a pretty good match. The bores are much bigger than the 10R.
One more part done. I'm quickly running out of stuff to machine...