Fueling Demands At A Digital Pace

It only seems natural. With the on set of the digital age, it’s no wonder the automotive market place is slowly following suit. From the integration of first generation On Board Diagnostics (OBDI) during the ’80s to the second, more advanced offering of OBDII beginning around ’94, and what seems like an endless supply of hand-held tuning capabilities recently, it’s about time an aftermarket manufacturer has upped their game.

With the enthusiast in mind, Fuelab took another look at supplying fuel to the brains of the operation, literally. Thankfully, aftermarket companies like Fuelab out of Litchfield, Illinois have become the foremost authority when it comes to fueling your project car, albeit now with more advanced, digital capabilities. Fuelab is no stranger to us either, and have even detailed some of their great products in previous mentions before.

To make installation simple, Fuelab uses common, -6AN (PN 52901) or -8AN (PN 52902) inlet and outlet fittings on the the 529 series. Also featured are 1/8-inch NPT gauge port with plug for an external pressure gauge.

Getting Fueled Up

These [traditional] systems produce so much heat, its like trying to control a vehicle at full throttle – Rob Scharfenberg

Let’s face it, these days making high horsepower mills with lots of down-low twist is painfully simple. Add in the overall availability and simplicity of an LS build; the doors for performance are wide open and easily accessible. Of course, with all that power comes the simple ingredients for making it work: fuel and air. Essentially, making reliable power is a no-brainer. In a nut shell, cram as much air and fuel down the intake, ignite it under pressure and viola!

Fuelab has introduced a key element to further simply the equation. With digital reliability becoming the means for control on many of our everyday personal products, its no wonder Fuelab has designed a way to incorporate all the control of a digital operating system into a mechanical-style component for your street or strip vehicle.

Of course, controlling fuel delivery in a vehicle is not a new concept. For what seems like eons, high-end builders and backyard wrenchers have needed a means for controlling fuel. Now, Fuelab’s digital fuel pressure regulator can control fuel demand, seamlessly through a digital processor.

An additional 1/8-inch NPT pressure reference port with a barbed fitting was also added to the 529 series regulators.

Fuelab, recently introduced its most innovative electronic fuel pressure regulator in their 529 series, which includes a -6AN and -8AN version. The new electronic fuel pressure operates quite simply. The Fuelab regulator uses a microprocessor in its base and operates in conjunction with Fuelab’s current line of Prodigy fuel pumps. Devised for street-strip and drag race applications generating up to 1,800hp, this new innovative, patented device communicates automatically with Fuelab’s Prodigy variable-speed pump.

The pump, in turn, responds instantly to fluctuating fuel flow demands and decreases current draw when in reduced speed mode, suppressing heat and potential vapor lock troubles in the fuel system. Before discussing the benefits of Fuelab’s digital fuel pressure regulator, it’s important to first understand how the traditional, mechanical style fuel regulator operates and functions as an integral member of any fuel system.

Fuelab’s latest innovation is installed and prepared for operation in the normal way: set the fuel pressure mechanically like a traditional bypassing regulator, then let the electronic regulator’s demand-based speed control take care of the rest.

How A Fuel Pressure Regulator Works:

  • High pressure fuel enters a chamber that has the regulator inlet and outlet.
  • High pressure fuel pushes against the diaphragm in the regulator, and acts against the spring behind the diaphragm.
  • The vacuum line attached to the nipple also acts against the diaphragm. As engine demand increases, so does the pressure acting on the diaphragm.
  • Under low fuel demand the majority of the pumped fuel is exiting the regulator bypass. The regulator bypass is sending unused fuel back to the fuel tank.
  • As more fuel is needed by the engine, less is sent through the regulator bypass.
A fuel pressure regulator is a device that is used to control the upper limit of the fuel pressure. Controlling this pressure is needed so that the carburetor can receive and dispense fuel at a known rate. As engine load increases, so does the demand for fuel. It’s also important to understand that any externally mounted mechanical regulator will require some type of bypass return line to the fuel tank.

Traditionally, a carbureted system’s fuel pressure should be generally set between 6 and 8 psi (measured at the carburetor) for a street engine (higher for a race engine). Keep in mind that fuel pressure is not fuel volume. Your pressure reading is only an indication of the level of restriction in the system. What’s more, Fuelab also offers traditional, mechanical fuel pressure regulators as well.

Fuelab Digital Fuel Pressure Regulator

These days, more and more serious builds are ending up as street driven vehicles. Even the most radically powered engines are being stuffed into cars, which for the most part, was almost unheard of just a few short years ago. Rarely would these builds ever see a city traffic light or freeway on ramp under its own power.

Used in conjunction with Fuelab's Prodigy fuel pumps, the Fuelab 529 series digital fuel regulator automatically senses demand from the engine and controls the pump flow directly. for faster reaction time but also brings the current draw down enough for easy street driving. traditional high-flow pumps at idle draw a lot of current, which in turns can heat up the fuel, potentially causing fuel vapor lock. The Fuelab digital fuel regulator can eliminates vapor lock and issues with short pump life.

Of course, the issue with driving a high-horsepower car on the street is wrought with drivability issues. Start cruising around your full-tilt race motor on the street and inevitably, those components which were only meant for limited driving begin to heat up. When it comes to fuel, vapor lock can begin to rear its ugly head and cut your cruise night short.

To get the inside scoop to efficiently fueling the demands of any project vehicle or daily driver and to avoid vapor lock, we contacted Fuelab’s Chief Engineer, Rob Scharfenberg. Fuelab’s methodology was simple: Eliminate heat build up and control fuel demand instantly from idle to full throttle situations. Scharfenberg outlined a lot of issues most owners might experience when it comes to fueling the high demands of a thirsty, high-zoot engine.

From an idle condition to fully open throttle the microprocessor generates a signal, sensing approximately 100 times each second. The signal is communicated by the microprocessor to Fuelab’s Prodigy fuel pump and with electronic accuracy the system precisely meters its fuel.

Case in point, heat. It’s a vehicles worst enemy and can quickly cause parts to fail. Fuelab recognized a large need for, “Speed reduction or speed control on high-flow fuel systems,” explained Scharfenberg. He added, “These [traditional] systems produce so much heat, its like trying to control a vehicle at full throttle.”

Essentially, Fuelab has created a way of throttling the fuel pump, which in turn keeps heat build up to a minimum and vapor lock a thing of the past. “Street driven applications could over heat the fuel, damage the pump, lose fuel pressure and cavitate,” stated Scharfenberg. Take into account the distance of the tank in relation to the engine, when heated by the pump, the gasoline could actually boil creating a vapor of gasoline which the fuel pump can’t handle.

Included with each 529 series Fuelab digital fuel regulator are the quick plug 'n' play connections which make installation a breeze. Simply line up the tab on the male side with the female, plug in the prongs and thread them together.

The Inner Workings

Of course, the Fuelab digital fuel pressure regulator isn’t just an ordinary regulator. In actuality, its quite the contrary. There’s a lot going on behind the scenes. As Scharfenberg explained, “The Fuelab digital fuel regulator outputs a signal, which the fuel pump communicates with.” In turn, the regulator controls the pump and dictates the flow to the demands of the engine.

Fuelab 529 Series Electronic Fuel Pressure Regulator Features

  • Works with Fuelab’s Prodigy Fuel Pump.
  • Patented method for demand based flow control, able to detect changes in demand before change in rail pressure is realized.
  • Automatically reduces current draw at low flow demand.
  • Monitoring capability to track actual fuel system capacity.
  • Get the quick response of a mechanically regulated system, with the advantage of electronic flow control.
  • Independent system, no other connections, control boxes or calibration required.

The Fuelab digital fuel regulator uses an ingenious method for determining its “target flow rate.” In this case, a target flow rate is essential for establishing the correct amount of fuel needed to supply the engine. In a nutshell the digital fuel pressure regulator operates quite simply.

Scharfenberg pointed out, “The return line acts like a restrict0r, which builds up pressure. By creating a pressure pocket in the return cavity, a target flow rate can be determined.” Of course, this is all occurring about 100 times per second as the digital fuel regulator communicates directly with the pump.

Scharfenberg added, “When disruption occurs within the target flow rate (positive or negative flow) the regulator will either add or decrease demand at the pump.” The benefits don’t stop there either.

Whether you’re at the drag strip or on the street during spirited driving adventures, “A constant return line on our system acts like a reserve. Even when pressure is lost and the pump doesn’t have time to react, there is an extra cushion of 40-50gph, which allows some dampening and the fuel pressure to remain stable.”

Fuelab’s fuel pressure regulator offers on demand fuel delivery and even includes the fittings and wiring harness. Additionally, all assembly of the Fuelab digital fuel regulators are done in-house at Fuelabs facility while machining is done locally. Ultimately, each regulator is available in six different color options including black, red, purple, gold and yes, even green; there’s one to fit your build.

Aside from the standard diaphragm and spring normally found in traditional fuel regulators, Fuelab adds their patented microprocessor unit, which communicates directly with the Fuelab line of pumps. What's more, the regulator body is completely CNC-machined to ensure high-quality standards.

Fuelab Prodigy Fuel Pumps

Need some serious flow? No Fuelab digital fuel pressure regulator system would be complete without the Prodigy fuel pump. Fuelabs Prodigy fuel pumps are quite capable of supplying most street to race applications, even engines rated to 1,800HP. Prodigy pumps use a DC brush less motor system with electronics that control the pump’s operation. The pumps use an input signal to determine the desired operating speed. By having this feature, pump speed becomes controllable, allowing continuous duty applications for high flow pumps and avoiding a full speed high current draw condition that leads to heat buildup and the potential for vapor lock.

All Prodigy fuel pumps are gasoline, diesel, methanol, and ethanol compatible. This allows the ability to support big power without a belt driven pump. Each pump is hand built and tested at the Fuelab facility in Litchfield, Illinois under strict quality and rigorous testing guidelines before shipping. Fuelab has eight models available ranging in performance levels; with flow rates up to 200GPH and operating pressures up to 125PSI.

Fuelab’s electronic fuel pressure regulator takes all the guess work out of fuel delivery. Their line of electronic fuel pressure regulators work in concert with the Prodigy line of fuel pumps to reduce heat build up and vapor lock conditions related to street/strip operation. Simply, set the pressure mechanically like a traditional bypass regulator, then let the electronic fuel pressure regulator’s demand based speed control take care of the rest.

Shannon Carnathan's '71 Nova utilizes a complete Fuelab fuel system, featuring twin Prodigy pumps and a Fuelab digital fuel regulator.

Fueling In The Real World

So, does the Fuelab system actually work and perform as desired? Just take a look at Shannon Carnathan’s ’71 Nova. Under the hood sits a twin-88mm turbocharged, 555-inch big-block outfitted with a set of heavy-breathing Profiler 375 Sniper cylinder heads, while a Holley Dominator EFI relying on 225 lb injectors system sit up top. Inside, a set of set of CP 22cc dished pistons provide a low, 8.9:1 compression ratio and swing on Oliver billet rods.

The Nova is good for 4.97 at 164 mph in the eighth-mile with a very respectable 1.30 60ft. time.

Carnathan’s Nova is no slouch, either. With 1,860hp on tap at the rear tires, it’s obvious, Carnathan was all-in on his Nova. A build of this magnitude isn’t left up for chance and to fuel this mill correctly, Carnathan went with a complete Fuelab fuel system.

Fuelab supplied Carnathans Nova with two, High Power EFI in-line Prodigy pumps, which works in concert with the Fuelab digitial fuel regulator. At a hefty 3,567 lbs, Carnathan’s big-block powered Nova is no stranger to the track.

To reiterate, Fuelab has devised these systems for street-strip and drag race applications generating up to 1,800hp. This new innovative, patented device communicates automatically with Fuelab’s Prodigy variable-speed pump. The pump, in turn, responds instantly to fluctuating fuel flow demands and decreases current draw when in reduced speed mode, suppressing heat and potential vapor lock troubles in the fuel system. From daily-drivers, street/strip cars and even full-tilt race cars, Fuelab has the components to fuel your vehicle no matter what the duty.

Underneath, Fuelab equipped the Nova with a dual pump setup with the pumps on the right and pre-filters to the left.


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About the author

Sean Haggai

The former Associate Editor of Chevy High Performance, joins publication Chevy Hardcore, Sean is a true blue Bow Tie guy and a core do-it-yourself technician. If it doesn't run a "mouse motor" or a big rat between fenders, Sean ain't interested.
Read My Articles

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