When new technologies come out it doesn't mean what you used was bad, it just means that some cat with a pocket protector figured out a way to do things just a bit more efficiently. In the automotive world many of these advancements were figured out initially by the OEs and later trickled down to the aftermarket. This is exactly what happened with the growth of Electronic Fuel Injection (EFI). Now, EFI has been around for a long time, but it wasn't until the mid '80s when Americans went "all in" and started dropping the use of carburetors. For OEs the driving reason for the switch was to meet new government emissions and mileage regulations. EFI also gave engines the ability to self-tune and adjust to changing conditions like altitude and temperature.
In the '90s, the easiest way to get EFI under the hood of your classic was to swap in something like a GM LT1 or LS1 engine along with all the OEM wiring and ECU. But recently the aftermarket has come up with systems that let those with older engines easily make the move to EFI. One such company to offer up EFI to the masses was Holley. Long known as the top dog in terms of carburetor technology, Holley figured that they could put all their fuel-delivery expertise to good use. They've recently taken their initial system and further refined it resulting in their new Terminator EFI kit. Their goal was to make the switch to EFI as painless as possible. To this end, the kit is very simple to install. The throttle body bolts on and hooks to the linkage just like one of their carbs. Almost all of the sensors come mounted to the throttle body and the wiring is clearly labeled and mostly a plug-and-play affair. They also designed the ECU to be capable of self tuning, which is a great feature for those who don't have access to a chassis dyno tuner. To see how easy it really is we decided to install their kit on our carbureted 350-stroker powered '72 Caprice.
We should note that while the kit contained everything for the EFI install, it didn't address the fuel system needed to support it. This is an area where you can spend very little, or quite a bit. As opposed to carburetors, EFI requires higher fuel pressures and this typically means a return-style fuel system. Now, if funds are tight you can modify your stock tank to accept a return line and run an inline electric pump and filters. Keep in mind, without internal tank baffling you could run into fuel-starvation issues during hard turns when the tank level is low. But, it will work for cruising about. For a bit more time and money, you can add baffling to your tank, or spend even more and get a ready-to-run, pre-built tank like we did. Our point is, the way we addressed the fuel needs isn't the only way to get from there to here. Still, expect the swap to EFI to set you back between $2,000 to $3,000.
The centerpiece of our Holley Terminator EFI kit (PN 55-406, $2,050) is this 950 CFM throttle body. The air entry area has been CFD computer designed for max airflow and much of its design was patterned off the NASCAR piece found on Sprint Cup Series cars. Our unit came in Holley's Hard Coat Grey finish, but they also offer it in tumbled polish for a few bucks less.
Key to the unit having such a small footprint is the integration of all the sensors and fuel injectors into the throttle body housing. The four 65 lb-per-hour injectors can support 250-600hp engines.
The sensors in the throttle body, like the Idle Air Control (IAC) Motor, Throttle Position Sensor (TPS), MAP sensor, Air Charge Temp Sensor, and fuel injectors are easily replaceable if needed. Best of all, most of this will eventually be hidden by the air cleaner.
One cool design feature of the new Terminator system is the switch to an annular discharge fuel ring. This way of injecting fuel into the air stream doesn't suffer from the delay and restrictions found in booster designs.
This was our starting point, a 350 small-block with an 850 Holley double-pumper carb.
After removing the carb we installed the water temp sensor that came in the Terminator kit. In this case we placed it in the rear port of our RHS intake manifold. Later, we found that the water tempurature back there was much cooler than the front, by well over 20 degrees, so we eventually relocated the sensor to the front of the intake manifold. This was necessary since the Terminator's ECU won't go into learn mode until it registers water temperature of at least 160 degrees.
The new throttle body bolted into place where the 4150-flange carburetor was it replaced. We decided to reuse our billet Lokar linkage plate, but the Terminator did include brackets for throttle and for transmissions like the TH350, 200R4, and 700-R4.
The linkage should be familiar to anyone that's messed with carburetors and the kit included all the throttle and linkage studs. It's highly recommended that a throttle return spring be used.
Included in the kit was also this main system harness. The Holley instructions (which are downloadable on their website) are very clear, but, in short, the harness needs to be run clear of any high-voltage "noisy/dirty" wires and, of course, away from high-heat items like headers. There's also a main power loom included in the kit. For this, the negative (black) wire was run directly to the negative post of the Optima battery and the positive (red) lead was run directly to the positive post on the battery. Again, both of these need to go directly to the battery.
We decided to mount the Holley ECU in the Caprice's interior so we used a 2-inch hole saw to make a hole in the lower section of the firewall. The ECU can be mounted in the engine bay, but it needs to be in a somewhat protected area and in a place where you can still hook up the handheld module. Under the dash seemed like a cleaner option.
The Terminator ECU is weather sealed to protect the internals from the elements and the easy-to-use handheld programming module is key to getting the system up and running. One very cool feature of this ECU, which sets it apart from some other systems on the market, is that, if needed, the ECU can be fine tuned via a laptop, just like Holley's top-of-the-line HP ECUs.
With the wire loom run though the grommet, and into the car's interior, the hook-up process was simple matter of pulling the clearly labeled wired into their corresponding sensors. The Terminator system also has provisions to control up to two electric fans for the radiator and it has an A/C Shutdown output that will deactivate the A/C at higher throttle positions. If the car has an ignition box, the Terminator can also adjust engine timing.
We then installed the system's Bosch wideband O2 sensor. To do this we first drilled a 7/8-inch hole in the passenger side Hooker header. The included boss was then fully welded to prevent leaks. Holley recommends that the sensor be located 1 to 10 inches after the collector.