Hear me out on this one: THIS MOD IS ESSENTIAL for boosting with a stock ECU and injectors. You can install a slightly larger injector with the stock ECU, but nothing huge. You can install 1.8L injectors on a 1.6L. You cannot install 550cc RX7 injectors though, the stock ECU cannot control those. The answer is to add an FMU that will increase fuel pressure as boost rises.