No need for any extra injectors and you have no way to meter the fuel. Up to 200bhp the standard efi can cope with minor mods. Ran mine for 6 years. But with out a recirc dump valve the airflow meter will wear due to reverse air flow. I have had to fit a spare due to this problem. A twin piston adjustable dump valve can be interesting, flames!! It can cause the ecu to dump more fuel in at gear changes