[KevinD]

rapid prototyping that thing will be a collosal waste of money. the ABS plastic they are made out of is very very brittle (others are made of plaster which is like handling paper thin glass). you wont be able to run it on a car, and if your very lucky you may be able to flow bench it at very very small pressure differentials to atmostpheric. your best bet is to use your cad software to make it into a sheetmetal drawings and get it laser cut or water jet cut. from there roll the cone by hand ( i don't see any other way of doing that), and just weld the rest together. you going to manufacturing them out of aluminum or stainless? keep in mind that aluminum corrodes with alcohol, and a large percentage of your clientel will be using alcohol injection... might want to consider coatings (or anodizing) in that case. manufacturability of that cone is going to be a ***** if you expect it to hold 30+ psi and not burst. aluminum doesn't like to be bent and the thicker you make it the more it tears when bending (or rolling in this case). additionally, welding those two pieces together is going to make it tough to keep the inside surface clean and smooth along the seam between the two parts (cone and plenum).

where are your injector bungs going to be? any specific angles for those guys? length along the runners?