A weekends airbox building

I spent the whole weekend building an airbox. It isn't obvious how to build an airbox. Lots of talk on forums but generally it is a bit of a mystery. Lots of talk about how the manufacturers must have got it perfect (because of budget). But actually they have some pretty serious restrictions (size for example). In the case of the gsxr1100 airbox, the design isn't of a very complicated design. It is designed as a Helmholtz resonator with an inlet of 50mm diameter, and 57mm length, although I am not sure about the volume. Further the flow to cylinders 1 and 4 is restricted a bit by the location of the frame.

Finally, I want to try secondary injection having those injectors in the air box firing down the trumpets. The idea is that injecting the fuel earlier allows it to mix up really well with the air, and also it extracts some heat from the air, which increases the charge density (cool air is denser than hot air). The net effect is that more oxygen gets into the cylinder, and also the fuel that is there is really nicely mixed up. Allegedly this is worth 5% bhp, and it popular on the latest sport bikes (cbr1000rr for example) and as it adds cost clearly they believe it worthwhile.

The result of all this meandering is that I need an airbox that won't burn, or dissolve in petrol.

Also I am keen to boost the airflow.

Requirements were:
Decent volume (>8 litres is an Andy Bates recommendation that I have read)

Cold air feed with diameter of 75mm

Interface to gsxr1000 TB's

Fits under bonnet!

Metal and not flammable

Mounting for secondary injectors

Manufacturable by me

So here is the design (made in cardboard)

And a few hours (and hours) later.

And finally fitted in the car. Its all a bit WW2 fighter control but I like it. The reason for the plexiglass window is so that I can see what is happening with the secondary injection (where is the fuel going).

I need to work out how to layout the pictures in this!!!!