Here's a little update:
I've got a rough CAD model completed, currently in the process of pulling off my stock intake manifold and getting it ready to throw on the CMM. Once I get it on the CMM, I'll be able to get some exact numbers instead of relying on my sh1tty vernier.
Done a bit of basic math and found my ideal runner area to be around 2.16" squared. I'll compare this to stock and throw some more numbers at formulas to see what sticks. Thinking 7.5" long runners into a smoother and larger plenum vs. stock. I'll do the acoustic boosting math and see if I can tune it to get something around 1psi at 7500 rpm on the second bounce. Stupid air pressure differentiation...
But right now, this was my first design:
As you can see, the bottom left section of the manifold is terrible. The fluid flow is so slow that it effectively stalls out and the flow through each runner differs by somewhere around 10%. I'm pretty much starving cylinder 1 here. I haven't seen the internals of the DD Performance manifold (seeing as it is the only example of aftermarket intake manifolds for the 2ZZ), but if it's the same cross sectional area throughout, like this, then I've got some improvements to make.
And improve I did.:
I added a slope to the interior to reduce the cross sectional area at each runner. As you can see from the simulated fluid flow, cylinder 1 is no longer starved, but simply inconvenienced slightly. There are some slight eddies and areas where fluid flow is almost non-existent. I'll take care of these by changing up the internal geometry a bit.
One solution I've found is changing the position of the throttle body; changing its attitude and position can have a huge affect on the flow to cylinder 1. I'm aiming at a more uniform fluid velocity throughout the manifold.
I'll keep you guys updated. Final CAD model should be done within the next two weeks I figure.
I need the intake manifold pressure that we run at 7500 rpm. Can someone please reply with the MAP @ 7500 rpm in a 2ZZ.