This is an excellent thread with a lot of useful information. However the topic of EFI can get overwhelming if there are more questions than answers. I'd like to make the point that the topic of an EFI (fuel system) and EFI (Electronics/Computer) are topics that can be addressed separately.
EFI Fuel system
There are many ways to do a fuel system. Basically, there needs to be a fuel line from the tank (inlet line) and a fuel line going back to the tank (return line). A high pressure fuel pump, a decent fuel pressure regulator and fuel injectors are needed to complete the system.
My fuel system is overkill for most. It was designed to support 800 supercharged horsepower. The size of the fuel pump and fuel lines I used are not necessary for a basic EFI conversion. However, my experience building my fuel system helped me to identify some points that I'd like to share.
1.) I made my return line larger than normal for EFI because if I wanted to go back to a carb, I could get a fuel pressure regulator that could drop the fuel pressure down as low as 6psi. If my return line was too small, it might not allow for fuel pressures to drop low enough for a carb.
2.) You need to address fuel slosh. EFI gas tanks have baffles that help prevent the fuel from sloshing around to limit the fuel pump from sucking air. I got a new gas tank and modified it by cutting it open and having baffles welded in. I also modified the tank to have the inlet line and the return line on the side of the tank. My fuel pump is an Aeromotive A-1000 and it’s externally mounted. I don’t have any major problems with my setup, but there are easier and better ways of doing it. If I had to do it again, I’d create a way to actually mount the pump in the tank and use the Walbro GSL392 255lph Fuel Pump that was suggested by another member. This is a small, powerful, quiet pump that can be mounted in the tank. Look at the EFI gas tank that XV Motorsports offers. It is a Mustang fuel pump bracket (that can fit the Walbro pump) mounted inside a Mopar fuel tank. Mustang guys that need more fuel than this often use two of these pumps.
3.) Don’t be cheap on your fuel system if you are trying to make real horsepower. Build the fuel system for the horsepower that you might want to make in the future. This way you can upgrade your engine and not have to worry about the fuel system again. It is cheaper to do it right the first time then to re-do and upgrade it later.
Again, if I was building an EFI fuel system today, I’d get a new tank and a Mustang fuel pump bracket and have the tank modified to fit the bracket like the XV Motorsport set up. I’d use the Walbro pump intank and later upgrade to two pumps if needed.
