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 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.
POWERJECTION I APPLICATIONS CFM: Throttle body: Finish: Part No.: Price*: 750 cfm die-cast satin 70000 $1,995.95 750 cfm die-cast polished 70001 $2,095.95 750 cfm billet machined 70002 $2,495.95 750 cfm billet polished 70003 $2,695.95 1,{{{200}}} cfm die-cast satin 70004 $2,095.00 1,200 cfm die-cast polished 70005 $2,195.00 1,200 cfm billet machined 70006 $2,595.00 1,200 cfm billet polished 70007 $2,795.00 *Pricing quoted from Performanceparts.com at time of publishing
