We normally think of aftermarket bolt-on EFI systems as the perfect modern upgrade for carbureted applications, which they are. But it seems that throttle-body-style systems like Edelbrock’s new E-Street EFI can also greatly simplify the retrofitting and tuning of a modern EFI engine in an older project vehicle.
Our test case is Karl Roekle’s shop truck, a mutated ’47 Ford pickup that was shortened, lowered, and modified with Model A body parts by his uncle many years ago. At one point, this “Roekle rat rod” was saddled with a small-block Chevy onboard, but Karl bleeds FoMoCo blue, so once he got title to the truck, he soon swapped in an EFI 351W sourced from a ’91 F-250 pickup. To run its port injection and processor- commanded distributor, Karl has been utilizing a non-mass air EEC-IV connected via a custom-made wiring harness. Backed by a non-electronic AOD tranny, his Windsor has remained pretty much stock, save for some long-tube headers. The problem? Actually there were three:
First and foremost, Karl and the EEC-IV could never get the combo to run quite right. It regularly fouled plugs and overall didn’t perform the way he thought 351 cubes should in such a light vehicle. Second, with its long-runner factory intake up top, the Windsor just never looked very cool or hot-roddish in Karl’s eyes (or ours, for that matter.) And lastly, if the EEC-IV couldn’t be tricked into making his 351W run properly when practically bone stock, Karl figured it would be utterly hopeless if he ever swapped in a racier cam and/or cylinder heads. And believe us; he wants to.
All of this led Mr. Roekle to Edelbrock’s recently introduced E-Street EFI, a plug-and-play system using a 4150-style, square-bore flange throttle body, and a processor that “learns” as you drive and self-tunes the fuel curve accordingly. It is also custom tunable via an included 7-inch touchscreen tablet with Bluetooth connectivity. In short, this is a sophisticated EFI system that doesn’t require an engineering degree to install or live with. Let’s see how it all worked out…
1. Karl Roekle’s self-described “rat rod” serves as shop truck (and shameless self-promotion tool) for his Ultimate Auto Repair business in Jackson, Michigan. The cut down and lightweight ’47 Ford pickup should run well with a ’91-vintage 351W onboard, but its performance was flat and uninspiring.
2. Plus, its (relatively) modern factory long-runner intake that visually dominated the top of the Windsor certainly didn’t match the truck’s otherwise retro theme. We dig the Mountain Dew overflow bottle, though.
3. The E-Street’s four-barrel throttle body has a 60-lb/hr fuel injector at the base of each of its bores, and can flow 1,000 cfm—enough to support up to 600 hp, according to Edelbrock. Visible protruding into the one bore is the system’s air temp sensor.
4. On the other side of the throttle body, manifold absolute pressure (orange arrow) and throttle-position (green arrow) sensors provide additional data necessary for the E-Street processor’s fuel calculations. There’s also an idle air control (IAC) valve not visible in this shot.
5. The E-Street’s ECU runs the outfit and communicates when desired, via Bluetooth, with the system’s included 7-inch color touchscreen tablet seen at left. This is two-way communication—the tablet can be used to program various functions in the ECU, but it can also display various engine data on the fly. Or, leave the tablet at home and just let the ECU do its thing.
6. If electronics intimidate you, fear not. The E-Street’s main wiring harness simply plugs in with unique, individually labeled connectors. The orange harness connects to your electric fuel pump; there’s a tach input harness configurable for various types of distributor and ignition, and the trio of white pigtails on the left come into play if you have electric fan(s) and/or air conditioning.
7. Like all modern injection systems, Edelbrock’s E-Street runs in closed-loop mode (once the vehicle warms up), taking constant feedback from the included wide-band oxygen sensor to help instantaneously assess and maintain correct air fuel ratios. As with any O2 sensor, unleaded fuel must be used.
8. If upgrading to the E-Street system from a square-bore carb, you’ll be able to use your old manifold, but Karl obviously needed a new one to replace his factory EFI lower, so he opted for Edelbrock’s Performer 351-W casting.
9. Another item on Karl’s required parts list was a new distributor. The factory TFI distributor previously in place had its timing functions controlled by Ford’s EEC-IV processor. The E-Street processor does not control ignition timing, so conversion to a straightforward mechanical/vacuum advance distributor was necessary.
10. If upgrading from a carb, you’ll need to convert to an electric fuel pump. Karl’s EFI-powered truck already had one of course (a 255-lph FRPP unit), but he needed a standalone fuel pressure regulator to dial in the E-Street’s required 50 psi.
11. Teardown began with removal of the 351’s TFI distributor cap and wires, but not before the engine was turned to top dead center on the number one cylinder, to ease eventual installation of the new distributor.
12. Then, Karl’s righthand man, Jacob DeKarske, set about removing the old long-runner upper intake. We won’t get into much detail on the specifics of this teardown, because each of your projects will obviously be different. And, yeah, we know that’s a strange place for a fender cover. We draped it there mostly to hide the reflections of our photo umbrellas in the ’47’s flat windshield panes.
13. While Jake tackled the mechanical teardown, Karl set about disconnecting and removing his ride’s old wiring harness. This harness had been custom made to try and make the EEC-IV processor happy and functional in Karl’s hot rod application.
14. Karl also removed the old EEC-IV processor from the rat rod’s cabin. You can see that the unofficial “chip tuning port” on the EEC had been well used over the years in trying to patch in workable calibrations. We suppose the EEC did alright, but there’s no way it was intended for retrofitting to non-factory projects like this.
15. Once the factory lower intake was removed, the Windsor was about as torn down as it needed to be. We were now ready to install the Performer 351-W intake and set the E-Street throttle body in place. Truthfully, about the slowest part of the whole project was the time it took for Karl and Jake to neaten up the rat rod’s existing wiring as we went along. We still got it done in just one day.
16. Already looks more like a hot rod engine, doesn’t it? In the foreground, you can see the old throttle linkage hanging over the valve cover. Because it was specific to the old factory EFI setup, it was soon completely removed and replaced with a Lokar throttle cable and pedal. If you’re simply upgrading from a carb, Edelbrock’s kit contains sufficient throttle cable hardware to do the job.
17. The fuel pressure regulator was mounted just inboard of the gnarly old transmission cooler on the firewall. Notice that the regulator feeds the front fuel rail on the throttle body (the return fuel line connects to the bottom of the regulator.) The throttle body’s rear fuel rail terminates in a fuel pressure sensor that will be connected to the Edelbrock main harness.
18. Here’s the completed throttle linkage (the lower cable is a carryover piece used for transmission kick-down.) Oh, and disregard the vacuum line seen running here to the fuel pressure regulator. We found out later (yes, the hard way) that the regulator should port to atmosphere, not to engine vacuum.
19. Soon it was time to begin connecting the E-Street’s main wiring harness; a simple job because no two connectors are alike, and all are labeled by Edelbrock (though most of the label tags have already been removed here).
20. The rat rod’s long-tube headers already had bungs fitted for the EEC-IV’s required O2 sensors. The passenger-side bung was plugged, and the kit’s wide-band sensor was threaded into the driver-side.
21. Karl tucked the Edelbrock ECU up high on the interior side of the firewall. The ECU can also be mounted underhood, but given that Karl’s ’47 has no hood, that option wasn’t viable, since the processor must be kept dry. We’re not delving into the details of wiring for the fuel pump and distributor, as each application will differ, but if you take the time to follow Edelbrock’s well-illustrated instruction booklet, you’ll have no problem at all. The company also has toll-free phone tech support, should you have any questions.
22. Topped for now with a simple aftermarket filter and scoop, Edelbrock’s E-Street EFI looks a lot more period-correct on Karl’s rat rod than did the previous OEM intake setup. More important, however, was how well it worked…
So, How Does It Work?
Now that you have the system physically installed, what happens next? This is where the included tablet gets its first workout in creating an initial “tune” before starting your engine for the first time. For it to do this, you simply enter some very basic info about your vehicle via the touchscreen interface. First, you enter engine displacement in cubic inches. Then you choose between three levels of cam duration—telling it whether your cam has 210 degrees or less, 210 to 230 degrees, or greater than 230 degrees. Then you tell it whether you have a regular or multi-spark/CDI ignition onboard, whether the fuel system is return-style or return-less, and what rev limit you’d like. That’s it. The tablet then computes a basic start-up tune and wirelessly transmits it to the ECU. Crank the key and you’re about ready for your first drive.
In Karl’s case, the Windsor fired right up, and immediately idled smoothly (the system has cold-start tables, just like any factory EFI processor.) Once warmed up, you can command a different idle speed via the tablet if you so choose (bear in mind that the E-Street ECU does not control ignition timing, so you’ll have to make sure your distributor is properly adjusted.) We then headed out for a short drive and it was immediately apparent that the 351 had much more crisp throttle response than before. It even sounded better, making us conclude that the old EEC-IV system had been commanding improper fuel and/or spark curves. Once the engine coolant reaches 150 degrees, the E-Street ECU then learns as you drive, constantly fine-tuning the fuel trims on the fly. Edelbrock suggests allowing a couple hundred miles after initial installation for the system to be fully optimized for your vehicle. And, yes, the E-Street will adapt automatically to airflow changes like upgraded cylinder heads, for example.
After the initial setup, the tablet can be switched to one of its monitoring modes if you want to observe various engine parameters. Or it can be shut off altogether, as the ECU is now operating automatically, unless and until you decide to use the tablet to do some tuning or fiddling of your own.
If you want more info about the tablet interface, Edelbrock’s website has a video of tablet operation at www.edelbrock.com/automotive_new/mc/efi/estreet_intro.shtml, and the system’s very thorough instruction PDF can be viewed and downloaded at www.edelbrock.com/automotive_new/misc/tech_center/install/3000/3600.pdf.
As for his rat rod, Karl is ecstatic about the greatly improved looks, performance, and manners of its otherwise unchanged 351W, and is looking forward to some cam and cylinder head upgrades—something he was afraid of attempting with the old EEC-IV processor in charge.