Toyota 4AGE have moped-like internals, good thing about is that it weights about nothing but for supercharging or turbocharging applications it's just pain in the ass. For example connecting rod bearings surface area is just about one third of 2TG, FJ20 or L-series engines, meaning that under boost very light pinging will destroy bottom end.

So if you want real power with low cost stay away from 4AGE....