21st Century Digital Toy

Just like anything else in life, it's easy to take EFI for granted when you live with it every day. GMHTP is EFI only--and with my knowledge of carburetors, it's a damn good thing, too. Personally, I'm not comfortable turning screws on a carb--I'm at ease playing with tuning on a laptop or calibrating sensors. But there are days when I let EFI get me down, too: searching for false knock that pulls WOT timing is a real pain in the ass, and tracing a short in a wire harness can very easily take days. It almost makes me yearn for those simple engine bays from the '50s and '60s, where two vacuum lines and five wires are the extent of the engine's complexity...almost.

Because anyone who gets caught up in the frustrations of modern-day fuel injection should spent a day with a buddy's carbureted car. There is no luxury of an electronic Engine Control Unit; the driver is the ECU. All of those smooth cold-starts and stumble-free part-throttle experiences are literally a thing of the past. And unless your buddy is a tuning wizard, the way the car runs on one day can be drastically different from the next. Live in the now, people: there's a reason why carbs have been blissfully absent from factory vehicles since 1986.

Jason Kugler's 1969 Nova is a prime example of the timeless styling/aging technology conundrum. Way-back Rallys and sexy, curved body lines make it a real looker, and Kugler has even upgraded to a crate 383 and a Dynotech Performance-built TH200-4R overdrive tranny. Trouble is, the crate mill's 750-cfm carb never was right, and several attempted tunes later, a similarly mistuned 600-cfm unit sat atop the intake. This is Kugler's only vehicle, so the constant good idle/bad performance or vise-versa was starting to get a little old on the way to work. Additionally, he's working toward a pro touring road-trip ride, and with the increasing cost of petrol, those 7-mpg performances just weren't going to cut it. But above all, nothing is as much of a letdown as having a cool old musclecar that just isn't very fast. It was time for a drastic change in the way that the 383 did business: there are several ways to remedy this, but hands-down, the easiest would be a DFI conversion from Accel.

DFI has three distinct options for enthusiasts looking to convert their carbed rides over to EFI: the big-torque, TPI-esque Street-Ram, the better breathing, hybrid Super-Ram, and the high flowing Pro-Ram. After consideration of the 224 duration-cammed, Dart-headed 383, the folks at DFI recommended the 1,200-cfm Pro-Ram for its ease of packaging and its ability to flow lots of air from 2000 to 6500 rpm--just what the gasping 383 needs. DFI Pro-Ram buyers also have the choice of a smaller 750-cfm unit utilizing 30-pound injectors, but the bigger Pro-Ram's 36 pound-per-hour injectors will offer enough flow at 80 percent duty cycle to reach 400 ponies at the wheels quite easily--and still leave room for more.

Accel/DFI recommends that the Pro-Ram fuel injection system be installed at one of its nearly 200 Engine Management Installation Centers (EMIC). Technicians who attend Accel's EMIC training learn about the installation and tuning of DFI products, and the tech put in charge of our swap was none other than the very talented Bill Hahn of Hahn Racecraft. For those of you unfamiliar with Bill, he's a turbo and aftermarket ECU guru who builds custom turbo kits and tunes everything from Ecotecs to Ford 5.0s, which sprout from all corners of his Yorkville, Illinois shop. So the Pro-Ram, along with a boatload of Accel and Mallory ignition components and fuel system pieces from Summit Racing, were shipped out to Hahn Racecraft. EMIC Bill Hahn recently picked up an elevated DynoJet with wide-band O2 capability for the ultimate in tuning, so we baselined the carbed 383 before getting to work.

The DFI harness is top-notch--Weatherpack connectors give protection from the elements and ensure positive connections, the black loom looks factory, and everything is labeled for ease of installation. One of the best features is the built-in grommets for passing the harness through the firewall--then keeping it there.	Fuel filtration and pressurization was left up to Accel--its 74702 fuel pump and 74720 fuel filter are both part of the kit. The pump is rated to 870 flywheel horses on a N/A engine (at about .42 BSFC).	Along with the fuel pump and filter, the remainder of the fuel system will be replaced with parts sourced from Summit Racing. Aeroquip -6 (part No. AER-FCA0620, $88) and -8 (part No. AER-FCA0820, $106) AN fuel lines will replace the stock ones. Aeroquip straight, 45-, 90-degree, and adapter fittings (part Nos. AER-FCM4033, 4023, 1013, 2526, 2525, 1012, 4022, and 4032, $6 to $18), a Spectre fuel line connector (part No. SPE3360, $9) and some fuel filter adapter fittings from Accel will make the connections. The Auto Meter air/fuel ratio gauge (part No. 2675, $150), though not a wide-band, will be a handy tuning tool for the DFI. A fuel pump blockoff plate (part No. SUM-401030 $3) was needed, as well.
Hahn Racecraft had been in its new Yorkville, Illinois facility for mere weeks before we came calling. HRC is known for its wicked Neon and Cavalier race cars, and as a supplier of turbo kits to the domestic and import sport compact scene. It expanded into a 12,000-foot manufacturing facility, which includes this 3,200-foot shop.	Here is the test subject: the Engine Factory 383 has a Speed-Pro 3000 cam with 224 duration and .460 lift, and Dart II heads with 2.02/1.60 valves. The 383 has suffered for years with improperly tuned 750- and 600-cfm carburetors--but that's all about to change!	The Hahn Racecraft crew got to work installing a bung in the exhaust for the DynoJet's wide-band O2 sensor. Judging from its owner's comments, there is a fuel system gremlin at work, and dyno time with a wide-band is a good way to find what it is.
...by disconnecting the battery, then removing the factory gas tank from the Nova.	The radiator cap is removed, then the radiator is drained.	Twelve intake manifold bolts are loosened with a 9/16-inch wrench.
The Nova's coil and distributor are loosened and removed.(Above) After double-checking that everything was disconnected, Martinelli removes the intake and carburetor.	With the intake gone, the Dart II heads are scraped to remove grime and old gasket material.	With the intake gone, the Dart II heads are scraped to remove grime and old gasket material.
Now it's time to test-fit the wiring harness and ignition systems. Bill Hahn drops the Pro-Ram manifold into place, and Craig connects all of the Weatherpacks to get an idea of how the wires will be run. The Hahn crew then placed the Mallory coil and ignition box onto the firewall to determine a mounting spot.	The harness will have no problem reaching all of its sensors, so Craig uses a 1 5/8-inch holesaw to put two holes into the firewall. These points are where the wiring harness will pass through.	Now, with Craig on one side and Bill Hahn on the other, the wiring harness is passed through the firewall. Although this takes care and lots of patience, the harness comes through until the grommets pop soundly into place. Four holes are drilled into the firewall left of the grommets to mount the Mallory coil.
The DFI ECU's mounting location will be under the passenger-side dash. Martinelli placed it so it would be out of harm's way, but would still be accessible if necessary.	Martinelli extends the DFI harness fuel pump power wire to run down the frame to where the pump will be mounted.	Back under the '69, seven 1/2-inch bolts and one 5/16-inch bolt are removed to pull the Nova's 5/16-inch fuel lines.
The mechanical fuel pump was removed and the blockoff plate was bolted up.	Car owner Kugler lends a hand by running the new fuel pump wire. It was routed down the passenger-side firewall to the frame, ending up in the passenger-side rear fender outside of the frame rail. Black loom covers it.	We got a fuel sump kit from Summit (part No. 4041, $62), to be welded to the bottom of the Nova's fuel tank. Bill Hahn would be wielding the TIG welder, and the first thing he did was test-fit the sump to the tank and make minor adjustments to the angle of the sump's flange with a sheetmetal box brake.
Once Bill was satisfied with the location of the sump, he marked the area to be cut. The tank had been dumped out two days prior, and a fan had been running constantly to completely dry it out. If there is even a semblance of gas or gas fumes left, a cutting wheel isn't exactly going to be your best friend here.	Using a wheel, Bill carefully cut the chunk of sheetmetal away to reveal the inside of the tank.	Hahn burned the midnight oil to clean up the cut, then TIG weld the sump onto the tank. The next morning, the tank was leak-tested with mineral spirits and cleaned up with mild soap and water, then the welds and sump were treated to an alcohol bath.
Finally, some black undercoating was applied to the tank.	Before reinstallation, the top of the factory fuel pump sender was plugged with a 1/16-inch NPT fitting and a new ground wire was run to replace the crusty stock one.	The newly sumped tank was placed on a trans jack and bolted back into position.
Time to test-fit the Accel fuel pump and filter. We'll be using -8 from the sump to the pump, then switch back to -6 for the rest. "Even the strongest fuel pump is very sensitive to restrictions on its inlet side, that's why the sump-to-filter-to-pump line is -8 AN, and the pump outlet-to-fuel rail can be -6," Bill explained.	Aeroquip -6 AN is used from the fuel pump to the rail, and from the rail back to the tank. Once the hose length was determined, Bill Hahn uses a chop saw to cut the hoses, flushes them out with solvent, and uses a liberal amount of engine oil inside them and on the fittings for final assembly. When they were ready to go, the lines were run and secured at the factory mounting points with clamps.	This sweet arrangement is the Nova's completed fuel sump/pump/filter setup. As you can see, the -8 runs from the sump, through the Accel filter, and to the Accel fuel pump, then -6 runs to the fuel rail. The -6 return line feeds back into the sump.
Before the final installation, the Pro-Ram intake was drilled and tapped for two additional sensors: the coolant temp sender for the Nova's temp gauge (bottom), and the Manifold Surface Temperature sensor (top). The latter is one of the key components of Gen. VII that separates it from the lesser versions. The ECU uses that temp info to assist in modeling the behavior of fuel film in the intake runner, which helps smooth out driveability and response issues that can plague less advanced programmable EFI systems.	With two new intake gaskets placed, Bill and Craig carefully set the Pro-Ram into position atop the 383 and bolt it down.	All sensors, including the extra coolant and MST, are connected. The injector harness is connected and all eight clips are attached to their respective injectors.
The Dual Sync distributor is dropped into place, Hahn test-fits the 10.8mm spark plug wires for length, and three ground wires, two for the distributor and one for the ignition lead off of the DFI, are grounded to a throttle body screw.	While Craig cuts the Accel wires to the correct length and installs them, a custom bracket for the HyFire 6A box is fabbed up and bolted down below the coil, then the box is attached and wired up.	The fully assembled Pro-Ram. With a project this big, you're bound to do some customization. With the Nova's 383, we shimmed the alternator bracket, modified the upper radiator hose to clear the fan, and mounted a custom ignition box bracket. A modified elbow was used for the heater hose, two 10-32 set screws in the front of the body plugged unused vacuum ports, and a plastic air filter riser was used for the air filter assembly to clear the throttle lever. HRC created a high-tech throttle linkage, and the MAP sensor was attached to the bottom of the air filter assembly (not shown). A rear vacuum port on the throttle body was used for vacuum to the brakes; another was used as a vacuum source for the MAP sensor.
The Pro-Ram was ready to rumble. We're not going to cover calibration, start-up, initial, road, or dyno tuning in Part I--we'll leave that for the November issue of GM High-Tech Performance. There is no doubt that this car was woefully ill-tuned before our DFI shenanigans began, but we will say that the difference--in power, economy, and driveability--was night and day. And we'll leave you with a clue to the final results: how does triple digits and over double sound to you?