The FourX Return-Type control system has everything needed to provide a stand-alone fuel pump speed control system for up to four high-power brushed pumps.
- Works with all brushed type fuel pumps
- Typical power reduction to the pump(s) of 45-75% during idle and cruise -> reduced heat generation
- Includes a stand-alone MAP sensor for pump speed and triggering control
- Easily change the #3/#4 pumps turn-on points with a simple voltmeter reading.
- All pumps are under PWM control.
- Plumb the fuel system using traditional regulators, filters, and return lines.
- Developed for the Radium Engineering Fuel Surge Tank 20-0992-XX but will work with any two, three, or four pump system.
- Carburetor and EFI capability.
High-horsepower pumping systems can create excessive heat that can lead to vapor lock. Vapor lock, a condition where the fuel somewhere in the system boils, causes fuel pressure to fall and pumping to effectively stop. It can happen anywhere from the pump inlet all the way to the fuel rails or carburetor bowl. With pumps being about 1/3 efficient, it is understandable that all of the OEM manufacturers are using a form of speed control to slow down the pump(s) during low fuel demand conditions.
Combine high power pumps and engine heat that is returned to the fuel tank on a return-type system, and the fuel tank becomes a large thermal battery. The hotter the fuel becomes, the more susceptible it is to vapor lock. It is very common on warm days that the fuel tank becomes so hot that it becomes uncomfortable to keep a hand on it.
Imagine the engine in your car running at wide open throttle all the time. Stuck in traffic with the engine going 6500rpm and roaring. Only a small fraction of the engine power is actually needed, hence, the need for a throttle. That is what Pulse Width Modulation is for fuel pumps, a power throttling mechanism.
There is more information on PWM pump control here: https://www.vaporworx.com/resources/fds/9-pwm-fuel-controllers/
Large pumps like the TI Automotive 450 and 525lph pumps can take 22+ amps to drive at full power. The 450lph pump, commonly referred to as the Hellcat pump, and the 525lph, or the Demon pump, are controlled by Mopar using Pulse Width Modulation. PWM is simply turning the pump on and off thousands of times per second. The longer the electrical pulse is on, the faster the pump(s) spins. However, there must be some kind of input/feedback to tell the electronics how to change the pump speed. The FourX uses a stand-alone MAP sensor to provide the feedback needed to control the pump speed.
The FourX system consists of a primary PWM controller and a secondary relay controller. Under normal idle/cruise driving, the #1 and #2 pumps are running. Even with both pumps running a near 30% reduction in power vs. a single full-speed pump is achieved. The #3 and #4 pumps are latched to the PWM controller by programmable relays. Each relay has a potentiometer that is used to set the turn-on point for each relay. Setting the on-point is as simple as reading a voltage on the relay controller and setting the potentiometer. The controller comes pre-set for approximately 3psi/9psi on settings for the #3/#4 relays. Since all pumps are connected through the PWM controller, they will ramp together in a smooth manner.
This system will provide approximately 35% power reduction to the dual operating pumps TI 450lph fuel pumps during idle and cruise vs. a single full speed pump, much lower noise, and increased pump life. Simply attach the MAP sensor hose to a manifold vacuum source, make at-idle controller adjustments, and the VaporWorx controller will do the rest. For carbureted applications, please contact VaporWorx so that an initial and under-power relay turn-on strategy can be done specifically for your application. Any standard carburetor low-pressure regulator with sufficient flowrate capacity for your combined pumps should work well.
The standard MAP sensor provided is a GM 4bar type. This sensor has shown to have more than adequate range. Since the amount of time that the #3/#4 relays will be on it is best to have them come on early, well before the point where fuel pressure is dropping. Any standard EFI pressure regulator with sufficient flowrate and pressure capacity should work well. Be sure to size your fuel lines accordingly. AN8 for up to 1200hp. AN10 for about 1200hp.
It is recommended that for supercharged applications that manifold referenced fuel pressure be used with the fuel pressure set to approximately 43psi at idle. This will reduce the load on the fuel pump(s) and the vehicle electrical system.
The FourX Controller includes these standard features:
- Everything needed electrically to drive three or four brushed fuel pump(s) electrically.
- Easy to set idle/cruise primary pump speed adjustments.
- #3/#4 pump turn on points adjustable from 12inhg to 30psi.
- A significant reduction in the average fuel pump power requirement resulting in lower fuel temperatures and longer pump life.
- Uses standard return-type plumbing systems. Can be used to replace currently installed Hobb’s/pressure switch + relay applications.
- 110A minimum continuous power rating in a compact controller package.
- Over-temperature shutdown with automatic reset that will operate indefinitely without damage.
- Short circuit output protection that will operate indefinitely without damage.
- OEM Delphi/Aptiv connections for terminals, seals, and connector bodies.
- All cross-linked polyethylene wiring.
- UL94 rated components used throughout.
- Integrates into the OE ECM to allow all safety systems to remain functional.
- 10-18v operating capacity. Lower than 10v applied to the turn on circuit will cause controller shutdown to protect from an AFR lean condition.
The basic wiring layout and connections are shown in the following diagram:
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