Injector calculationsBased on information found in Four-Stroke Performance Tuning by A. Grahamm Bell there are some basic calculations that can be done on injectors to see how far they scale. I've used these calculations in the injectorlist below.
Injector static flow = (Required flow * 100) / (injectors per cylinder * duty cycle)
Required flow = (maximum horsepower * K) / number of cylinders
Combined for the Speedster/VX220:
Max power == SF * (D / 100) * 4 / K
Where D is the duty cycle in percentage.
To recalculate the flow of an injector at a different fuel pressure, the following formula can be used:
new flow = old flow * sqrt(new pressure/oldpressure)
Without specification injector flowrates should be at 3bar. The z22se runs the fuel rails at 3.8bar.
For prolonged use at high rpm's it is best to keep the duty cycle of an injector below 80%.
Injector listBased on a lot of searching on the web I've found the following injectors which seem interesting for use on the Speedster/VX220 2.2 because they are the right type and have the correct connector.
Standard Z22SE injectors
Z22SE compressor upgrade injectors
Standard LSJ injectors
Stage 1/2 LSJ injectors