1976 Chevy Camaro - Power I Fuel Injection System

For around $2,000, the Professional... 

   

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For around $2,000, the Professional Products Powerjection I will give you the street manners, economy, and throttle response of EFI, while retaining the good looks, simplicity, and ease of installation of a carburetor.

Every new car built since 1988 has had electronic fuel injection, so the novelty of swapping your muscle car over to EFI has long left the building. In fact, the battle lines between the EFI crowd and the carb crowd were drawn a long time ago, and each PHR reader probably has a well-defined opinion on the matter, and has discovered his or her own camp years back. Regardless of which faction you identify with, you're in for a big surprise with the Powerjection I EFI system by Professional Products.

The Powerjection I looks like a carburetor, and essentially installs like one. And like a carburetor, you don't need a laptop to drive off into the sunset. All that simplicity does come with a price, though: Dollar for dollar, the Powerjection system (which arguably encompasses way more than a carburetor) costs about four times what a nicely optioned 750-cfm modular 4150 double-pumper costs. Nevertheless, you will realize additional benefits for that extra dinero, such as superior cold start, idle, throttle response, and fuel economy. Moreover, your engine will retain the sex appeal of a carbureted induction setup, air cleaner and all.

Hardcore carburetor lovers will want to give the Powerjection a hard look. Unless you really just like messing with carbs, the seasonal ritual of rejetting and tweaking the tune-up just isn't part of the Powerjection's repertoire. Yet you won't need a computer for the Powerjection, either. A first in the standalone EFI market, the Powerjection's computer is self-learning, and needs no laptop. We were extremely skeptical of this claim, and decided to experience it firsthand using our '76 Camaro, Project g/28, as a guinea pig. Not only did the Powerjection fire up and settle down to a perfect idle with the first turn of the ignition switch, we quickly discovered how well-mannered it was on the street relative to our old 750-cfm double-pumper.

The self-learning computer is the key to the whole cost/benefit equation. Professional Products employs a wide-band oxygen sensor that makes it all possible (you must have the requisite bung welded to your exhaust). This feeds data to a small on-board control module called the EMS. The EMS has been preprogrammed to seek out a 14:1 air/fuel ratio at cruise, and a 12.5:1 air/fuel ratio at wide-open throttle. When the system is fired up the first time, the EMS rapidly makes corrections to the fuel delivery throughout the load map until all the operating cells are filled. As a variety of driving conditions are encountered, additional data is stored and/or updated. Within a period of about a half hour, all programming is completed, and you never break out the laptop once! All you do is drive around, which is what you were going to do anyway. As a side note, users have the option of connecting to the EMS via a USB cable. This allows you to reset the air/fuel ratio targets to your liking.

From a simplicity standpoint, we like how the Powerjection allows the user to retain his or her existing carbureted manifold. (Currently, the 4150-style bolt pattern is the only one supported.) And while it might not seem like a big deal at first blush, the Powerjection is the only aftermarket EFI system that doesn't require a fuel return line (applications up to about 550 hp). This is huge, and will save you at least a half-day's work over all the competing EFI systems. Your existing throttle cable and linkage are also retained.

As with other EFI conversions, there is also the obligatory mounting of a computer (in this case, the EMS), the installation of sensors (coolant temp, MAP, oxygen sensor, fuel pressure, tach), the routing of preterminated harness wires (power lead, computer, fuel pump control, sensor leads, idle air control), and the installation of a fuel pump.

Each Powerjection unit and... 

   

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Each Powerjection unit and its companion computer are run on a real engine before being shipped. This checks for leaks, and any running problems before units get in customers' hands. It's the same size and shape as a carburetor, which allows it to fit a huge range of manifolds for all makes of engines.

We came to the table ready for the possibility that this EFI swap could be a lot of hassle for a minimum benefit. We even hedged our bet by saving the old carb and fuel pump, just in case we needed to quietly put it back on. (Because it's so easy to swap back to a carb, that in itself makes it perfect for skeptics.) Right from the get-go, we noticed a difference. We'd grown accustomed to nursing the throttle on start-up with the carb, but the Powerjection started right up without touching the gas pedal once. When pulling away from a stop, we were able to drive it like a newer EFI car-once again, no pumping or pampering the throttle to get rolling. Once moving, the throttle response was noticeably sharper-and our old double-pumper had been no slouch in that area. But we were really sold on the conversion when we hit the gas pump the first time, and bumped up our fuel economy from 17 mpg to a little over 18 mpg.

Swapping out a traditional carb for the Professional Products Powerjection I is so simple, even a caveman can do it. We can only come to the conclusion that, ironically, only a caveman wouldn't do just that.

The Powerjection I was previously...        read full caption The Powerjection I was previously known as the RetroTek BossEFI. Professional Products knows a good thing when they see it, and acquired RetroTek last year. The unit we opted to install on our Vortec 350 small-block was the die-cast, satin-finish 750-cfm model (PN 70000). We were easily able to find this model for sale online for under $2,000.	A view from the bottom reveals...        read full caption A view from the bottom reveals the Powerjection's true nature: Four 60 lb/hr injectors can safely feed 550 hp, and are hidden in faux "float bowl" covers. Note the black harness between the injectors on the right: This fuel pressure sensor helps the EMS computer manage the system's fuel pump. This allows the fuel system to be returnless, thus making installation much easier.	Installation is simply a matter...        read full caption Installation is simply a matter of unbolting your old carburetor, and bolting the Powerjection on. No manifold swap is required and the unit comes tested and preassembled. If you have an automatic, you'll need one more step for mounting the transmission kickdown.
We reused our old throttle...        read full caption We reused our old throttle cable and throttle linkage. There are two mounting options on the throttle bell crank; we chose the low-leverage position since the throttle shaft springs in the new EFI throttle body are lighter than the old carb.	The EMS computer controls...        read full caption The EMS computer controls the Powerjection, and needs to be mounted in a cool, dry place. We chose this out-of-the-way location behind the dash on the passenger-side firewall.	Once you know where your EMS...        read full caption Once you know where your EMS computer will be mounted, find (or make) a small hole in the firewall to fish the computer harness through. We used a preexisting hole that had a factory plug. One of the first things you'll then do is find a good place on the engine to attach the ground wire.
The Professional Products...        read full caption The Professional Products Crosswind intake manifold on Project g/28 has two tapped bosses for coolant sensors-the front one was being used for our Auto Meter coolant temp gauge, so we used the second one near the firewall to mount the EFI coolant temp sensor. Note that you'll need to disconnect the battery and drain the coolant before starting.	The 1-bar MAP (manifold absolute...        read full caption The 1-bar MAP (manifold absolute pressure) sensor was then mounted high on the firewall near our harness passage. The harness connections for all the sensors are preterminated-just snap them on as you go through the installation checklist.	We'd done some instrumented...        read full caption We'd done some instrumented chassis dyno testing a while back, so we had an oxygen sensor bung already welded aft of our header collector. All we needed to do was pull the plug, and thread in the wide-band sensor.
We didn't leave the wiring...        read full caption We didn't leave the wiring this way, but we wanted to show you how all the extra harness length was nicely gathered and zip-tied together. Note the small red box, which is the signal conditioner for the wide-band oxygen sensor. The entire bundle was then snugged under the dash and tied up. Note the USB cable on the floor. We're leaving this under the floor mat in case we want to reset the air/fuel ratio targets for the self-programming function.	Every induction system, be...        read full caption Every induction system, be it carbed or EFI, needs some way to get fuel. Fortunately, we were able to reuse the factory feed line since our Vortec 350 (see "Budget Sledgehammer," December 2006) topped out at 447 on the DTS engine dyno. You won't need to plumb a return line unless you're making over 550 hp. Professional Products makes a return fuel line kit (PN 70106, $324.50) which has 25 feet of -6AN braided line, a selection of 24 AN fittings, a regulator, and prefilter. Most people use it as a feed line, and convert the factory feed line to a return line.	Don't be confused by the four-link...        read full caption Don't be confused by the four-link Air Ride Technologies AirBar suspension in our '76 Camaro. The Powerjection fuel pump installation won't be any different in stock leaf-spring cars. The new pump is mounted to the chassis and the wiring is connected to the EMS via the supplied harness. The pump (and prefilter) tap into the existing factory fuel line.
After connecting all the sensors...        read full caption After connecting all the sensors and actuator harnesses, replacing the coolant, and hooking up the battery, you're ready to fire it up. At this point, it's just been started, and Ken Farrell of Professional Products is adjusting the idle screw. The great thing about the Powerjection is that it senses the change in rpm, and resets the internal idle target to the adjustment you just made. That's just the opposite of what most EFI systems do, which try to take all your adjustments back out through the idle control valve. Notice the difference? You're telling the computer what to do, not the other way around.	Besides better driveability...        read full caption Besides better driveability and throttle response, we also picked up some economy. We noticed an improvement from 17 mpg to just over 18 mpg in highway driving, without any loss of performance.