Yeah, you only really need higher flow injectors if you're doing some really serious boosting as I am sure any heavily modded WRX owner will tell you. For the amount of gain you'd be getting out of the supercharger, the stock injectors should be plenty. Once you run high boost(lots more air), an intercooler, etc. and are turning a couple hundred horespower more is when injectors come into play. I don't even think the transmission would be able to take that.