DeatschWerks DW400 Fuel Pump: The Ultimate 415LPH In-Tank Upgrade for High-Horsepower Builds
If you are building a performance engine that demands more than 1,000 horsepower on gasoline or 750 horsepower on E85, the DeatschWerks DW400 fuel pump is the highest-flowing in-tank pump currently available on the market, delivering 415 liters per hour at 40 psi with proven reliability backed by a 3-year warranty. This pump outflows competitors like the Walbro 450 by an average of 31 percent between 70 and 100 psi, making it the clear choice for serious builds where fuel delivery cannot be a weak link. Manufactured in Germany through a collaboration with Bosch Aftermarket, the DW400 combines German engineering precision with American performance tuning expertise. Whether you are upgrading a daily driver that sees occasional track time or building a dedicated race car, this pump deserves serious consideration.
What Makes the DW400 Different from Other High-Flow Pumps
The DeatschWerks DW400 is not just another high-flow pump with a larger number stamped on the side. It represents a fundamental engineering approach that prioritizes real-world performance over marketing claims.
Flow Performance That Actually Matters
The DW400 delivers 500 liters per hour at zero pressure and 415 liters per hour at 40 psi, which is the standard operating pressure for most modern fuel injection systems. But the real story is what happens at higher pressures. When you run forced induction or high-compression naturally aspirated engines, fuel pressure rises with boost pressure through the fuel pressure regulator. At 80 psi, the DW400 still flows 350 liters per hour. At 100 psi, it flows significantly more than any comparable pump in its class.
Compared directly to the Walbro 450, which many builders consider the gold standard, the DW400 shows measurable advantages. At 40 psi, the DW400 flows about 5 percent more fuel. But as pressure increases, the gap widens dramatically. At 70 psi, the DW400 outperforms the Walbro 450 by 18 percent. At 100 psi, the advantage grows to 56 percent. For builders running high-boost turbo setups or supercharged applications where fuel pressure routinely exceeds 70 psi, this difference can mean the difference between a safe air-fuel ratio and a lean condition that destroys pistons.
German Manufacturing with Bosch Collaboration
The DW400 is manufactured in Germany through a direct collaboration between DeatschWerks and Bosch Aftermarket. This is not a generic pump with a brand name stuck on it. Bosch brings decades of fuel system engineering experience, and the pump is built on the same production lines that supply original equipment manufacturers worldwide. The pump exceeds the specifications of SAE J1537, which is the industry standard for electric fuel pump performance testing. When you buy a DW400, you are getting manufacturing quality that meets or exceeds what automakers demand from their suppliers.
E85 Compatibility Built In, Not Patched On
Many aftermarket fuel pumps claim E85 compatibility, but they achieve it through after-the-fort modifications or material substitutions that can compromise reliability. The DW400 was designed from the ground up for ethanol fuels. It features carbon commutators and brushes, which resist the corrosion and wear that ethanol causes in standard copper commutators. The armature is fully encapsulated and machine-balanced, protecting the internal windings from ethanol's solvent properties. The composite turbine impeller is also engineered to withstand the chemical attack of high-ethanol fuels. If you plan to run E85, the DW400 gives you confidence that the pump will last.
Pulse Width Modulation Compatibility
Modern vehicles increasingly use pulse width modulated pump controllers to vary fuel pump speed based on demand. This improves fuel temperature management and reduces noise at idle. The DW400 is fully compatible with PWM controllers, meaning it can be used as a drop-in replacement in late-model vehicles that use this technology. Many older high-flow pumps cannot handle PWM signals and will fail prematurely if used with a factory controller. The DW400 eliminates this concern.
Physical Size and Installation Considerations
Before you buy any fuel pump, you need to understand whether it will physically fit in your vehicle. The DW400 has specifications that differ from standard pumps.
Diameter and Length
The DW400 has a 46mm diameter, which is about 16 percent larger than the standard 39mm diameter found in most in-tank pumps. This extra size allows for the larger internal components necessary to achieve 415 liters per hour of flow. However, it also means the pump may not fit into every factory fuel pump module without modification.
The overall length is approximately 11.5 centimeters, which is similar to many standard pump modules but must be verified against your specific application. Some vehicles have tight clearance inside the fuel tank, and a pump that is too long will not allow the module to sit flush against the tank flange.
Universal Fitment vs. Application-Specific Kits
The DW400 is sold as a universal fitment pump with an included installation kit. The kit contains fuel hose, hose clamps, an electrical wiring harness, and a fuel filter. This universal approach gives you flexibility, but it also means you may need to make modifications to your factory fuel pump module to get everything to fit properly.
Fortunately, DeatschWerks has released multiple application-specific fitment kits that make installation much easier for popular vehicles. As of 2018, the company offers eight fitment kits covering 21 popular applications, including the 2011-2017 Ford Mustang 5.0L Coyote, 2005-2010 Ford Mustang, 1985-1997 Ford Mustang, Mazda Miata MX5, Nissan Skyline R33, Nissan 300ZX Z32, Subaru WRX STi, and various DSM applications. These kits include everything needed for a direct drop-in fitment, including specialty brackets, wiring adapters, and step-by-step instructions.
Check Valve Consideration
One important technical detail: the DW400 does not have an internal check valve. In a factory fuel system, the check valve prevents fuel from draining back into the tank when the engine is off, which maintains fuel pressure at the injectors for quick starts. Without a check valve, you may experience longer cranking times after the vehicle has sat for several hours, because the fuel has drained back to the tank.
If you experience hard starting, you can add an in-line check valve in the fuel line near the pump outlet. These are inexpensive and easy to install. Many builders choose to add a check valve regardless, because it ensures consistent starting performance regardless of the pump's internal design.
Wiring Requirements for the DW400
A pump that draws 16 to 20 amps at operating pressure requires proper electrical support. Skimping on wiring is one of the most common causes of premature pump failure.
Minimum Wire Gauge
DeatschWerks strongly recommends using a 10-gauge hardwire kit to ensure the pump receives adequate voltage. The company offers its own kit under part number FPHWK-10-HD, but any quality 10-gauge relay kit will work. Standard factory wiring for fuel pumps is often 16 or 18 gauge, which is sufficient for a 60 to 80 liter per hour pump drawing 6 to 8 amps. When you upgrade to a pump that draws three times that current, the factory wiring becomes a bottleneck that causes voltage drop.
Voltage Drop Consequences
Voltage drop is the enemy of high-performance fuel pumps. If the pump receives only 11 volts instead of 13.5 volts, flow drops significantly. At 11 volts, the DW400 might flow only 300 liters per hour instead of 415. This defeats the purpose of buying a high-flow pump in the first place. Worse, running a pump at reduced voltage causes the motor to draw higher current to compensate, generating excess heat that shortens pump life.
Use a multimeter to check voltage at the pump connector while the engine is running. You want to see at least 13 volts at idle and no less than 12.5 volts under load. If you see lower numbers, upgrade the wiring before finalizing your installation.
Relay and Fuse Sizing
Install a 20-amp relay with an ignition-switched trigger. This protects your ignition switch from carrying the full pump current. Use a 20-amp fuse or circuit breaker in the power feed to the pump. Never exceed 25 amps for the fuse, because a larger fuse might not blow quickly enough to protect the wiring in case of a short circuit.
Tuning Data and Expected Power Levels
The DW400 is rated to support more than 1,000 horsepower on gasoline and approximately 750 horsepower on E85. These numbers come from DeatschWerks' internal testing and are realistic for properly tuned engines.
The difference between gasoline and E85 power ratings exists because ethanol requires approximately 30 percent more fuel volume to achieve the same air-fuel ratio. A pump that flows enough fuel for 1,000 horsepower on gasoline will only support about 750 horsepower on E85 because the engine needs more fuel per horsepower.
If you are building an engine that exceeds these power levels, you may need to run two DW400 pumps in parallel or step up to a different pump solution. However, for the vast majority of street and track builds, a single DW400 provides plenty of headroom.
What Comes in the Box
When you purchase a DeatschWerks DW400 universal fuel pump, the package includes:
- One DW400 fuel pump unit
- One universal installation kit containing:
- Fuel hose rated for submersible in-tank use
- Hose clamps designed for fuel system applications
- Electrical wiring harness with connectors
- Fuel filter/strainer
The universal kit gives you the basic components needed for installation, but you may need additional parts depending on your specific vehicle. For example, if your factory fuel pump module uses a specific mounting bracket or electrical connector, you may need to source those separately or adapt the universal kit components.
Why You Should Consider KEMSO Fuel Pumps as an Alternative
While the DeatschWerks DW400 is an excellent pump for high-horsepower builds, many vehicle owners do not need 415 liters per hour of flow. For daily drivers, mild performance builds, and standard replacements, KEMSO fuel pumps offer OEM replacement quality with a lifetime warranty at competitive prices. Every KEMSO pump is engineered to meet or exceed original equipment specifications, giving you factory-level fit, performance, and reliability without paying dealership prices.
OEM Replacement Quality with Performance Benefits
KEMSO pumps are designed as direct OEM replacements for stock pumps that have gone faulty. Compared to your stock OEM fuel pump, a KEMSO pump delivers over 20 percent more flow at 43 psi. This extra flow provides a safety margin for performance upgrades or simply ensures consistent fuel delivery as your vehicle ages. Whether you drive a daily commuter, a heavy-duty truck, or a performance car, KEMSO pumps are built to handle the job.
The pumps are designed for both gasoline and E85/ethanol, with internal seals and motors specifically rated for ethanol's corrosive properties. This means you can switch to E85 in the future without worrying about pump compatibility.
What You Get in a KEMSO Pump Kit
Each KEMSO pump kit comes with everything needed for a complete installation. A typical kit includes:
- One genuine KEMSO fuel pump
- Multiple gradient density fuel strainers to cover different model variations
- Flexible hose and rubber hose sections
- Rubber base and mounting hardware
- Wiring connectors and crimp connectors
- Hose clamps and zip ties
The pump body diameter is either 30mm or 38mm depending on the application, and the overall length is approximately 11.5cm for the 38mm version. Flow rate is 200 liters per hour at 43 psi and 13.5 volts, with operational pressure ranging from 43 to 68 psi. This makes KEMSO pumps suitable for a wide range of EFI applications, from daily drivers to fast road cars.
Unrivaled Quality Control
KEMSO distinguishes itself from cheap aftermarket pumps through rigorous quality control. Every pump is individually tested with documented flow testing results. The company maintains a quality control program that meets ISO/TSO standards, which is rare for aftermarket fuel pump manufacturers. When you buy KEMSO, you are not getting an unbranded unit with unknown performance characteristics. You are getting a pump with verified flow numbers and proven reliability.
Lifetime Warranty Gives You Peace of Mind
The most compelling reason to choose KEMSO is the lifetime warranty. KEMSO backs every fuel pump with a lifetime warranty that covers you as long as you own your vehicle. The serialized fuel pump body guarantees this warranty coverage. If a pump fails due to a manufacturing defect, KEMSO will replace it at no cost.
Think about what this means in practical terms. A fuel pump replacement typically costs between 600 and 1,200 dollars including parts and labor at a professional shop. If a cheap pump fails in two years, you pay that entire cost again. With a KEMSO pump, you pay once and never pay for a replacement pump again. The lifetime warranty transforms a one-time purchase into a permanent solution.
USA-Based Support
KEMSO support for their pumps is USA-based and provided by USA technicians. If you have installation questions or need troubleshooting assistance, you can speak directly with knowledgeable staff who understand American vehicles and driving conditions. This level of support is rare among budget pump manufacturers and adds significant value to your purchase.
Visit KEMSO Racing Today
To browse the complete KEMSO fuel pump lineup and find the exact pump for your vehicle, visit https://www.kemsoracing.com/. The website features detailed product descriptions, compatibility information, customer reviews, and installation guides. Whether you are replacing a failing OEM pump in a daily driver or upgrading a performance build, KEMSO has the right pump for you.
The product catalog covers vehicles ranging from Audi and BMW to Honda, Kawasaki, Polaris, Can-Am, and many more. With KEMSO's lifetime warranty and OEM-quality construction, you are making a smart investment in your vehicle's long-term reliability.
Installation Tips for Any Fuel Pump Upgrade
Whether you choose the DeatschWerks DW400 or a KEMSO pump, proper installation is critical for long-term reliability.
Keep the Fuel Tank Clean
When you have the fuel pump module removed, inspect the inside of the tank. Look for debris, rust, or sediment. If the tank is dirty, clean it thoroughly before installing the new pump. Any debris that enters the new pump will cause premature wear and potential failure.
Replace the Fuel Filter
Always replace the fuel filter when you replace the fuel pump. A clogged filter creates backpressure that forces the pump to work harder, increasing current draw and reducing flow. A new fuel filter costs between 10 and 50 dollars and can prevent premature failure of your new pump.
Use Submersible Fuel Hose
If your installation requires cutting or replacing any fuel hose inside the tank, use SAE 30R10 rated hose. Standard fuel line will degrade when submerged in gasoline or ethanol, causing fuel contamination and potential pump damage. The submersible hose costs slightly more but is essential for in-tank applications.
Check All Connections
Ensure all electrical connections are clean, tight, and protected from moisture. Use heat shrink connectors or dielectric grease on exposed terminals. A loose or corroded connection creates resistance that generates heat and reduces voltage to the pump.
Prime the System Before Starting
Before you start the engine, prime the fuel system by cycling the key to the on position several times. This fills the new pump and fuel lines with fuel and removes air from the system. Attempting to start with an empty pump can cause the pump to run dry, which damages the internal components.
Troubleshooting Common Fuel Pump Problems
Even with a quality pump, issues can arise. Here are common problems and their solutions.
Engine Cranks but Will Not Start
If the engine cranks but does not start after a pump replacement, check for power at the pump connector. Use a test light or multimeter to verify that the pump receives 12 volts when the key is turned to the on position. If there is no power, the problem is likely in the wiring, relay, or fuse, not the pump itself.
Pump Runs but No Fuel Pressure
If the pump runs but you get no fuel pressure, check for a kinked fuel line, a clogged filter, or an incorrectly installed check valve. Also verify that the pump is installed with the correct polarity. Reversing the connections can cause the pump to run backward, which produces no flow.
Loud or Noisy Pump Operation
Some pump noise is normal, especially with high-flow pumps. But if the pump becomes significantly louder than when first installed, check for debris in the pump inlet or a loose mounting bracket. A pump that vibrates against the tank wall will amplify noise throughout the vehicle.
Final Thoughts
The DeatschWerks DW400 fuel pump is the right choice if you need the highest possible flow from an in-tank pump. Its 415 liters per hour capacity, German manufacturing quality, and E85 compatibility make it suitable for builds targeting 1,000 horsepower on gasoline or 750 horsepower on E85. The 3-year warranty and technical support from DeatschWerks add confidence to your purchase.
But for most vehicle owners who need reliable fuel delivery without chasing maximum horsepower numbers, KEMSO fuel pumps offer a compelling alternative. The OEM replacement quality, 20 percent flow improvement over stock pumps, and lifetime warranty provide exceptional value. You get a pump that fits perfectly, performs reliably, and never needs to be purchased again.
The decision comes down to your specific needs. If you are building a high-horsepower race car, the DW400 is the benchmark. If you want a reliable daily driver or mild performance upgrade that will last the life of your vehicle, KEMSO is the smart choice.
Before you buy any fuel pump, confirm the diagnosis with a fuel pressure test. Verify your vehicle's specific pump dimensions and electrical requirements. Compare prices from multiple retailers, and factor in the cost of any additional installation parts you may need.
For the best combination of performance, quality, and warranty protection, visit https://www.kemsoracing.com/ to explore the full KEMSO fuel pump lineup. With fast shipping and expert support, KEMSO makes it easy to get back on the road with reliable fuel delivery.