Dead center in the port and as close as you can get to pointing straight down the middle of the port in the head..
One of the reasons for an anti-reversion shield being placed over the top of Webers in the GT is to trap the reversion fuel spray and allowing it to become liquid once again where it then drips down to the top of the plenum and evaporates...That's a nifty system! Looks a lot like the early F1 car fuel injection system, where they also had injectors suspended over ITB's. Saw a few of those configurations at the Ferrari Museum in Modena Italy.
I don't think I'd like free-spraying fuel in the back of my GT though, without a manifold around it like you'd have on your Alfa.
Maybe one day for a fire breathing drag strip beast? Would be awesome to see your fuel being delivered as you hurling down the strip!
JP, which 480cc Pico's are you using?Pico njectores come in single hole (480cc) and twelve hole (the larger ones) and they beheave different
May be excess back pressure in the exhaust as the turbo slows down when the throttle snaps shut. This slowing the exhaust turbine which then leads to the pressure building in the chamber due to exhaust valve overlap with the intake valve. ie both valves are open for a short period of time. Exhaust Air then flows back into the plenum. I don't know, i am not an expert.I'm intrigued by the behavior of the fuel injection here, at times the fuel is even coming back into plenum chamber.