Plenums

I think Nick did a great job for a hobby kit to keep prices in line for his R&D & manufacturing costs. At this point I'd like to go in with you guys & design something that optimizes the setup. If we can agree on design parameters & have someone build 5-10 at once we could make it more affordable to each of us & have an end product better suited to us than any individual effort. Agreed ?
Maybe we could start at the TB & work backwards ? (Boots can be addressed as we progress ) Can we design around 58mm units ? Our ID going up to the plenum would be 58mm and flared at the top. What length do we need ( TB flange bottom to top of velocity stack ) ? Looking at the Trask set up ( most common, but very similar in most ) in appears that a center inlet, between the cylinders coming from the right side of the bike would be most efficient. It would entail relocating the coolant hoses but that seems a minor consideration. A Y shape might enhance air balance & physical positioning of necessary periferals. Are we heading the right direction ? Who's in ? THX

Here are some items I came up with on the subject, feel free to comment;
The charge tube on the Trask has three curves, two at 90 degrees and two 45's, length of pipe is about 24 inches. Total of 270 degrees of curve ( ID is a little less than 1.75". It then hits the weld in inlet with an app ID of 1.5". That is a LOT of restriction. The turbine side has to work to overcome that back pressure that becomes greater as speed increases, until the two cancel each other out & increase in boost in halted. It then blasts over the top of the inlets & would create a vacume at the rear port, hence the need for the V-shaped divider in an attempt to diffuse the air equally. It then hits the dead air boundry layer where the down tubes join the plenum.
If the heater hoses were re-routed the compressor housing could be clocked to 10 o'clock and the charge tube angled toward the middle of the intake ports. The tube could be shortened to maybe ten inches and have a single 45 and 90. The inlet to the plenum should have a matching 1.75 ID using a 1.75 to 2.25 silicone reducer. The charge would enter the side at a downward angle thru a wider portion that would begin to difuse the incoming flow. Using a 4.5" ID D tube ( My Trask is a 3.5" ID by 8.5" long, or about 80 cubic inches volume ) we can angle cut the top at the ends to direct the air flow and utilize stock length 9 each different) stacks with bell mouths, to increase flow from the center of the plenum & not be in boundry layer & take advantage of the factory dyno time to maximize intake tract length for each cylinder. The attached sketch might help illustrate this.
Tell me am I off base ? What could be done to improve this ? my guess is 5 -8 HP improvement with better turbo efficiency. Porting & cams would benefit even more.

breather setup; There is a post here somewhere that shows the internal dimensions / layout. I need the idle air layout for the intake flange that Karzza drew, can't find it. Anybody remember what it was posted in ?

Karzza, The ideal situation would be a turbo for each cylinder, then the only issue becomes volume to fill the cylinder between the valve and the compressor outlet. We have one turbo feeding two cylinders so we get back & forth motion in the common air supply ( plenum or charge tubes ). The closest example I can find is the S&S Pro stock motor. It uses a common air box, designed by the rules to force additional pressure in at 200 mph. We are using a pump to do the same thing, but we have issues with balance between the turbine and compressor sides. Our discussion now is the intake side. We can do the math to determine sufficient volume for each cylinder, however because we have to relieve pressure when the throttle is closed the intake tracts need to be joined. Pressure will always go from high to the low area. Therefore a bigger plenum with the BOV located to draw from it will minimize the changes in the runners & soften any wave harmonics. For racing, at a specific rpm, it would appear that an individual runner design could be advantageous, but you're getting into flow math that is WAY outside what I can comprehend. I feel that a plenum, designed for maximum flow, is going to be the best all around compromise for street or street/strip Vrods. If anyone has better data, please correct any of this.