10. The FAST EZ-EFI wiring harness looks intimidating rolled up—but stretched out it becom
Installing the EZ-EFI couldn’t be “ezier” with the exception of the coolant temperature and the O2 sensors, all the others come installed in the throttle body. The wiring harness is clearly labeled and the Electronic Control Unit, or ECU, is compact making it easy to find a mounting location. A new high-pressure fuel pump is required, and in our case plumbing dual fuel tanks does complicate things a bit, but we’ll show all that when we install the engine.
The FAST throttle body will bolt in place on any manifold that will accept a 4150-style carburetor, and just like a carburetor, the injector’s performance will respond to the manifold’s design. For operating in the higher rpm ranges a single-plane manifold might be considered. For our purposes we opted for a dual-plane manifold for enhanced low- and mid-range power.
Once the system is installed the included Setup Wizard is plugged in—it’s then a matter of answering questions and the ECU does the rest. With the target air/fuel ratios set the system starts out with basic closed-loop operation, which means ECU is comparing readings from the wideband O2 sensor to the targets established for idle, cruise, and wide-open throttle. What happens next is a testament to the sophistication of this system—the ECU then makes corrections by adding or subtracting an amount of fuel to make those two numbers match. The amazing part is the ECU then takes those correction percentages and makes a fuel map based on them. That’s one smart little black box.
From the moment John started the engine on the dyno we all felt our goal was about to be met. After the first pull, saying we’re pleased with our new engine is an understatement and the results speak for themselves. The peaks of 671 lb-ft of torque and 542 horsepower were impressive, but even more so for our purposes are the averages—from 2,500 to 5,000 rpm; 638 lb-ft of torque and 452 horsepower. That’s the makings of a real Hot Rod Hauler. CCT
12. We were thrilled with the dyno results and the ECU was still learning.
Here the A/F readings are N/A as we were using that sensor for the ECU.