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.
The Terminator kit included a lot of parts, but we still had to bring the fuel system up to EFI standards. This is an area that can vary wildly in price depending on how you want to tackle it. In short, the system requires a pump capable of supplying 400-pounds-per-hour at 45 PSI and the proper filters (down to 10 microns) need to be installed. Holley offers a variety of kits, but we chose the EFI kit (PN 526-3, $600) that included an in-line fuel pump, billet regulator, billet 100 and 10-micron fuel filters, Earl’s Super Stock hose, and Super Stock push-on fittings. Since we ended up replacing the tank, we would have been better served to buy what we needed from Holley a-la-carte.
One super easy, and great looking, way to address the fuel system is to go with something like this Aeromotive Stealth fuel tank (PN 18567, $700). It’s built around a powdercoated Tanks Inc, fully baffled, replacement gas tank. Inside there’s a 340 Stealth turbine-style electric fuel pump and a GM 0-90 ohm sending unit. This is an especially good idea if high-g manuvers are planned since the design ensures that pump stays submerged even at low fuel levels. It came to us fully assembled and ready to install. We hit up Ground Up for their gas tank installation kit (B13-2-B, $13), which included new foam isolator pads.
The pump had three ports that needed to be dealt with, feed line, return line, and vent. The ports were ORB-06 style so we had to make a run down to the local speed shop for some fittings. The system supports naturally aspirated EFI engines up to 850 hp, so it’s more than capable of feeding our small-block. We should note that the Holley harness had a wire (green) that could directly power a pump up to 15 amps. The Aeromotive pump drew right around 15 amps so we decided to play it safe and install a relay and use the green wire to trigger it. If you use the inline pump that comes in the Holley kit then you’re good-to-go since it draws less than 10 amps.
We decided to mount the billet Holley fuel regulator to the firewall just above the heater box. We also tossed on an Aeromotive 1-100 psi fuel pressure gauge. It’s a great spot since Holley recommends that it be installed after the throttle body. In our case, we decided to use the Caprice’s existing hard line as the return and run the new Earl’s Super Stock hose for the feed. We just felt better relying on the Earl’s fittings to hold the EFI pressure rather than hose clamps on the factory hard line. The 40-micron Holley filter was plumbed into the feed line from the tank.
Since we wanted to be able to read fuel pressure with our handheld unit, we installed a Holley 0-100 psi fuel pressure transducer (PN 554-102, $112) in the fuel rail. If you want to skip it, the system will run fine, but you’ll get an LEr message on the handheld display.
We also removed the mechanical fuel pump and pushrod. To seal up the block we used a plate and gasket that came in the terminator kit.
The tank included a small vent fitting, but we really couldn’t find a good spot to mount it. The problem was finding a spot, higher than the gas cap, that didn’t let fumes into the trunk and was safe from road debris. Another big benefit is that, in addition to the fuel vent, it also handles the differential. Trust us that having gas slosh out of your vent every time you start, stop, or turn, or having your diff puke gear oil when it gets hot, is a real drag.
Testing And Tuning
A new EFI system is useless if you can’t get it up and running and in this regard the Terminator system excels. By setting some basic parameters with the handheld, the ECU is able to get the car started and from there it learns as you idle and drive. For the system to enter learn mode, all the sensors must be plugged in, the unit has to have a clean tach signal, and the ECU must sense that the water temperature is at least 160 degrees. It’s not complicated, but it is a process and thankfully the procedures, along with a troubleshooting guide, are well documented in the installation booklet. Here are some of the basics.
Using the small joystick we clicked through the menu to the appropriate screens. In addition to tuning, the handheld also has monitor and gauge functions. These are very handy for seeing what’s going on with the system and troubleshooting if necessary. We started by answering some basic questions, using the calibration wizard, such as engine displacement, what style camshaft, system part number, ignition source, etc.
The next step in firing up the Caprice was to set the TPS. Once we got the message that the TPS Autoset was successful we were ready to fire the engine. We admit we were a bit surprised when the engine fired up on the first attempt. We then followed the suggestions for letting the system start the self-tune process. Once fired, we also checked the car for any coolant or fuel leaks and opened the Monitor menu on the handheld to make sure the sensors were all reading correctly. This is where we figured out that the temp sender needed to be moved to the forward, hotter area of the intake manifold.
The Camaro was running better, but were getting erratic IAC readings along with a high-idle rpm and the system was stumbling a bit. To troubleshoot the system we took the easy route and brought the Caprice to the guys at Westech Performance. Chassis dyno tech Eric Rhee was able to plug his laptop into the Terminator ECU and see a ton of information not available on the handheld.
For the system to work it needs a good tach signal. We had the yellow wire on the harness hooked to the negative post on our coil. Normally this is fine, but Eric found we were picking up excessive “noise” and that wasn’t making the Terminator happy. The solution ended up being simple. The Terminator system has a pigtail for use with ignition boxes like the MSD 6A. The wires in this loom, unlike the yellow wire we were using, are shielded, so Eric tagged a wire from the ignition box pigtail and ran it to the positive post on the coil. We then used the handheld, under Ignition Setup, to tell the system we were getting our tach signal from a CD ignition box.
With a clean tach signal the system was able to tune as we drove around and the more we drove the Caprice the better everything ran. One thing that helped was we made sure to vary how we drove the car, so the system could “fill in more blanks” in the tune. Now the Caprice fires up just like a new car and runs silky smooth. And, while we’re pretty sure the engine didn’t pick up any power, we did notice the engine’s power band felt a bit different, mainly more responsive. We also noticed a slight improvement in fuel economy, but our lack of an overdrive gear made that a bit hard to quantify. What we do know is that our Caprice’s drivability is much improved and that makes the effort more than worthwhile.
Axalta Paint Tip
Go Slow To Get That Glow
This month’s Axalta Coating Systems paint tip advises everyone out there who loves to get down and spray their paint to always use slow hardeners, controllers, and reducers for that cleaner finish and less use of materials result. Whether you are spraying solvent or waterbase paint, all painters (new school or old school) need to slow down to speed up in the end and final finish. That’s right, slow means a cleaner, smoother finish that will require less sanding labor when the final stages of the buff-out demand that glass luster look. Let the product save you time, material, and labor from spending countless hours in the color-sand and buff department trying to correct all the imperfections and orange peel effects. It’s that simple my friends when you want to deliver that showroom gloss finish right out of the booth. Work smarter, not harder by slowing down to speed up and let the product do the work for you! Go slow and for any other paint tech advice, please feel free to contact Product Specialist Steven Chaparro at firstname.lastname@example.org.