The very first step in tuning a custom EFI system is choosing a fuel injector size.  There are almost infinite resources online for picking a good fuel injector flow rate (a.k.a. "size").  Here are a couple we like:

• Fuel Injector Size Calculator from Iroczone
• Calculator from the MegaSquirt inventors Bowling and Grippo
• From RC Fuel Injection

Here is a spreadsheet that can help create a Base Fuel Map, useful for EFI computers that do not make this easy for you.  If you know your approximate torque curve and other injection basics, you can create an approximate Base Fuel Map.  Check out this spreadsheet at let us know if you have any comments or questions:

• Base Fuel Map Estimator   (MS Excel Format)