B16 manifold. Work in progress

started working on this manifold. this manifold will be designed for a high reving engine, 9000rpm at least. the plenum will be increased by 314cc, runners 21mm shorter and wider runners, +2mm.
 OEM manifols usually are designed with smaller plenum, longer and narrower runners seeking for a good throttle response,good idle keeping the air moving forward as the intake valves open an shut.
 When an intake valve opens, there is a short lag before the cylinder starts to pull air through the runner into the combustion chamber. A longer runner helps maintain the inertia of the air column so it will fill the cylinder faster.
Shorter runners, on the other hand, usually flow better at higher engine rpm. Reducing the length of the runners may allow the engine to make more power at the top end, but the trade-off may be a loss of power and torque at lower speeds.
 we'll see if my math and theory works on this manifold. there is an inconvenient on my design, due to i am using oem manifold, , the oem runners are curved, so cutting and decreasing the length of the runners, don't match, so i have to reduce the diammeter of the runner in the point i am going to wel both pieces.