For the carbs I can understand it, sorry but for the fuel injection currently I can't. I use my Sprint on the race track only so any performance gains will be taken into considiration. Engine will use fully customizable engine management including fuel injection but I don't see what different throttle bodies will bring me.
Also consider the height of your setup. Using stock throttle bodies + air horns on top of those it just fits und the bodies. If you use manifolds on top of the heads and on top of that throttle bodies and air horns I think it will stick out of the bonnet?
FYI: I am not saying it is all bad or rubbish. It is just that I would like to understand what the benefit of anything I add to the car will be.
Well you'd use the ITB's for the same reason as carbs, in that they offer a more direct airflow into the engine as opposed to the air filter/plenum intake setup on the standard engine. But the advantage being that the fueling can be accurately measured and injected with ITB's, coupled with a cold intake system and custom ECU etc., you're sure to see power gains over standard setup. Plus, ITB's can mean larger, more 'aggressive' injectors and pressures as they don't have to be standard.
Clearance shouldn't be an issue, I use 40mm Dell'Orto's with fairly tall trumpets on my 8v, the ITB's can be bought with varying heights and the computer design of the ports on the manifold allow for a low height, maximum flow setup.
I have no Pics yet, Kamm. I shall update though! It's still being measured at the moment. As for using plastic, as alfa-g has said, they'll withstand the temps no problem. Plenty of car manufactures use plastic for manifolds already, Rover K-series being a good example.
The plastic is thermally rigid at engine face temperature (~120C avg.), but it has the protection of a cork/plastic gasket on the mating face, plus the intake air cooling it from the inside out!
Plenty have been made using alloy, even steel. My idea allows for an accurately designed, easily produced, cheaper alternative to the metal ones (I hope anyway, we'll see
) that requires little finishing and minimal waste.
I'll keep progress updated! If I get a low batch production go ahead (20 or so) I'll be selling some off to recoup the costs, so watch this space!