The original airbox on the dyno testing was a huge 10 litres in size and an ugly square aluminium box, which might suit a dyno room but is a total no-go when trying to fit it into the streamliner chassis. From extensive, ok, a few websites i believe that the minimum size is X10 the engine capacity, and this is to allow for damping of the input pulses. Single engine need a bit more than mutli-cylinder as the pulses in a multi balance each other out, bit like a four into one exhaust. So i have slimmed it down to 5 litres, still 50 times the capacity!
This just so happens to be the size of the polystyrene blocks i bought for moulding stuff out of. So i am making a fibreglass airbox by using this block as a buck and will make a 5 sided block and a detachable lid, as i might yet need to build into the lid the ability to have an aluminium heat sink and ice bucket, to act as an intercooler.
Now some of you will realise the error of my thoughts, yep, fibreglass resin dissolves polystryrene!
so i wrapped the block in kitchen foil, then used copious amounts of duct tape to insulate the block from the resin, and i have to say i'm well happy. the 2 components have formed well, i did it onto aluminium and it seems to be releasing easily. looks solid and the part, and once fully hardened, just needs a trim.
From the attached photos, you will see i have machined the aluminium stubs that the hoses will connect to, these i will bond in with PU mastic/adhesive, and then resin over to keep it airtight, as it need to withstand 15psi of boost.
Overall, one happy chap.