I never understood how they did that, but I just went and looked at howthingswork and figured it out. My conceptual model of a 2 stroke was based on my goped's engines, but those are non-reed-valve 2 strokes that draw fuel and air straight through the intake port up on the cylinder. You cannot turbocharge a goped 2 stroke, to whoever posted above- the air would just flow straight out the exhaust port. I can see a possibility for turbocharging benefits on a reed valve 2 stroke. The piston is already compressing the air/fuel in the crankcase before it flows into the cylinder, adding a turbo would compress it even more. I see more of a potential for scavenging and making sure the cylinder is completely full of air/fuel and not exhaust than for building positive boost pressure, but I could see a turbo being used with a tuned pipe to blow a lot more air and fuel into the tuned pipe and then having the boost pressure sort of "ram into" the resonance waves sending air and fuel back into the cylinder. It sounds very complicated and tricky to tune, if my guess is right. But if I'm right you COULD turbocharge a goped, because Trevor Simpson makes billet reed induction cases that would let this principle of turbocharging work.