DW400 Fuel Pump: The Ultimate High-Performance In-Tank Upgrade for Your Build
If you are building a high-horsepower engine and need a single in-tank fuel pump that can support over 1,000 horsepower on gasoline or 750 horsepower on E85, the DeatschWerks DW400 fuel pump is the highest-flowing brushed in-tank pump currently available on the market. This pump delivers an industry-leading 415 liters per hour at 40 psi, and more importantly, it outflows the Walbro 450 by an average of 31 percent in the critical 70 to 100 psi pressure range where modern boosted engines make their peak power. Manufactured in Germany through a collaboration with Bosch Automotive Aftermarket, the DW400 combines German engineering quality with E85 compatibility, pulse width modulation compatibility, and a three-year no-fault warranty. However, before you buy, you need to understand the wiring requirements, fitment considerations, and the fact that this pump does not include an internal check valve. This guide covers everything you need to know about the DW400 fuel pump, including its specifications, real-world performance, installation tips, and a strong recommendation for an alternative worth considering.
What Makes the DW400 Fuel Pump Stand Out
The DW400 is not just another fuel pump. It was specifically engineered to solve the problem that many high-performance builders face: maintaining adequate fuel flow under high boost pressure. When you run a supercharged or turbocharged engine, your fuel pressure rises with boost pressure. Most pumps lose significant flow as pressure increases, but the DW400 was designed to hold its flow曲线 much better than competitors.
Flow Numbers That Matter
The raw flow numbers tell an impressive story. At zero pressure, the DW400 flows 500 liters per hour. At 40 psi, which is a typical base pressure for many fuel injection systems, it delivers 415 liters per hour. But the real test comes at higher pressures. At 80 psi, the DW400 still flows 350 liters per hour, and at 100 psi, it delivers 297 liters per hour. This means the pump can support more than 1,000 horsepower on gasoline and up to 750 horsepower on E85, making it suitable for serious street cars, track cars, and even some competition vehicles.
How It Compares to the Walbro 450
The Walbro 450 has long been considered the benchmark for high-flow in-tank pumps, especially the E85 version. However, the DW400 significantly outperforms it. At 40 psi, the DW400 flows only about 5 percent more than the Walbro 450, but the gap widens dramatically as pressure increases. At 70 psi, the DW400 flows 18 percent more. At 100 psi, the advantage grows to 56 percent more flow. This is critical because most boosted engines operate in the 70 to 100 psi range under full load. If your pump cannot maintain flow at those pressures, your engine will run lean, which can cause detonation and catastrophic failure.
German Engineering and Bosch Quality
The DW400 is manufactured in Germany through a collaboration between DeatschWerks and Bosch Automotive Aftermarket. Bosch is one of the most respected names in automotive components, and their involvement ensures that the pump meets strict quality standards. The pump exceeds the specifications of SAE J1537, which is the industry standard for electric fuel pumps. The carbon commutators and brushes, fully encapsulated and machine-balanced armature, and composite turbine impeller are all designed for durability and long service life.
Key Features You Need to Know
E85 Compatibility
If you plan to run E85 ethanol fuel, the DW400 is built for it. The carbon commutators and fully encapsulated armature protect the pump from the corrosive effects of ethanol. Many pumps fail prematurely when used with E85 because ethanol attracts moisture and can damage internal components. The DW400 avoids this problem with its materials and construction.
Pulse Width Modulation Compatibility
Modern fuel systems often use pulse width modulation to control fuel pump speed and reduce noise. The DW400 is compatible with PWM pump controllers, which means you can use it with factory or aftermarket PWM systems without issues. The turbine impeller design also contributes to quiet operation, which is a welcome feature for daily drivers.
46mm Diameter Body
The DW400 has a 46mm diameter body. This is 16 percent smaller than the Walbro 450's 55mm bell bottom design, which makes it easier to fit into many factory fuel pump modules. However, it is also 7mm larger than the standard 39mm in-tank pump. This means you will likely need to modify your fuel pump module or hanger to accommodate the larger diameter. Do not expect a direct drop-in fit for most vehicles.
No Internal Check Valve
One important detail that many buyers overlook: the DW400 does not have an internal check valve. The check valve is what holds fuel pressure in the lines after the engine is shut off. Without it, fuel can drain back into the tank, which can cause hard starts, especially after the car has been sitting for a while. DeatschWerks recommends installing an in-line check valve if you experience starting issues. Some newer versions of the DW400 may include an integrated check valve, so check the specific part number you are purchasing.
Installation Considerations
Wiring Requirements
The DW400 draws substantial current. At 40 psi, it draws about 16.1 amps at 13.5 volts. At 100 psi, current draw increases to 21 amps. This is a lot of current for a fuel pump, and your factory wiring may not be up to the task. DeatschWerks strongly recommends using a hardwire kit, specifically their part number FPHWK or FPHWK-10-HD, to ensure maximum voltage reaches the pump. Using thin or undersized wiring can cause voltage drop, which reduces pump performance and can lead to fuel starvation under load. A 10-gauge wire is recommended for the power supply.
Fuel Pump Module Modifications
Because the DW400 is 46mm in diameter, you will likely need to modify your factory fuel pump module. Many OEM modules are designed for 39mm pumps. You may need to enlarge the opening or use a different mounting method. Some aftermarket fuel pump hangers are available that are designed specifically for 46mm pumps. If you are not comfortable with modifications, consider purchasing a universal fuel pump module or a custom hanger.
Universal Fitment Kit
The DW400 ships with a universal installation kit that includes a fuel filter, wiring harness, fuel hose, and clamps. This kit provides everything you need for a basic installation, but it is not vehicle-specific. You will still need to source any additional fittings or adapters required for your particular vehicle.
Performance Expectations
Gasoline Applications
On gasoline, the DW400 can support over 1,000 horsepower. This makes it suitable for big turbo builds, supercharged V8s, and high-horsepower imports. If you are running a naturally aspirated engine that makes 600 to 700 horsepower, this pump will provide more than enough flow with plenty of headroom.
E85 Applications
On E85, the DW400 can support up to 750 horsepower. E85 requires approximately 30 percent more fuel flow than gasoline because it has a lower energy density. The DW400's high flow rate compensates for this, allowing you to run E85 on moderately high-horsepower builds without needing a second pump.
Boosted Applications
Where the DW400 truly shines is in boosted applications. The ability to maintain flow at 70 to 100 psi is what sets this pump apart. Many pumps that flow well at 40 psi drop off sharply at higher pressures. The DW400 holds its flow much better, which means you can run higher boost levels without worrying about fuel pressure limitations.
Common Questions About the DW400
Is the DW400 noisy?
The DW400 uses a turbine impeller design, which is inherently quieter than some other pump designs. Users generally report that it is quiet during normal operation, especially when used with a PWM controller. However, because it is a high-flow pump, you will hear it running, especially at full output.
Can I use the DW400 in a daily driver?
Yes, many people use the DW400 in daily drivers. The E85 compatibility, PWM compatibility, and quiet operation make it suitable for street use. Just be aware of the wiring requirements and the need for a check valve if you experience hard starts.
Does the DW400 come with a warranty?
Yes, all DeatschWerks fuel pumps are backed by a three-year no-fault warranty. This means if the pump fails for any reason within three years of purchase, it will be replaced. This warranty is to the original purchaser and is non-transferable.
Alternatives to Consider: KEMSO Fuel Pumps
While the DW400 is an excellent pump, it is not the only option on the market, and it may not be the best fit for every application. One alternative worth serious consideration is KEMSO fuel pumps.
KEMSO is a brand that has been manufacturing high-performance fuel pumps since 1999, with their headquarters and warehouse located in Houston, Texas. What sets KEMSO apart is their focus on OEM replacement and performance upgrades, combined with a lifetime warranty that gives you confidence in your purchase.
Why Consider KEMSO
KEMSO fuel pumps are designed as direct OEM replacements for a wide range of vehicles, including cars, trucks, SUVs, and powersports applications. They deliver over 20 percent more flow than stock pumps at 43 psi, which provides a noticeable performance improvement without the complexity of a full fuel system overhaul. The pumps are built with robust aluminum alloy bodies, making them durable enough for demanding automotive environments. They are also designed for compatibility with both gasoline and E85 ethanol fuels, so you do not have to worry about fuel compatibility issues.
Lifetime Warranty
Perhaps the most compelling reason to choose KEMSO is the lifetime warranty. KEMSO fuel pumps that fail due to defects in workmanship or material are replaced under warranty at any time. This lifetime confidence guarantee applies to the original customer and is non-transferable. When you buy a KEMSO pump, you are making a one-time investment in your vehicle's fuel system, knowing that the manufacturer stands behind their product for as long as you own it.
USA-Based Support
KEMSO is based in Houston, Texas, and they provide USA-based technical support. This means you can speak with knowledgeable technicians who understand your application and can help you with installation questions or troubleshooting. For many buyers, having access to local support is a significant advantage over brands that are based overseas.
To learn more about KEMSO fuel pumps and find the right pump for your vehicle, visit their website at:
Final Verdict on the DW400 Fuel Pump
The DeatschWerks DW400 is a legitimate high-performance fuel pump that delivers class-leading flow, especially at high pressures. If you are building a boosted engine that requires 70 to 100 psi of fuel pressure and you want a single in-tank pump that can handle the job, the DW400 is one of the best options available. The Bosch manufacturing quality, E85 compatibility, and three-year warranty add to its appeal.
However, the DW400 is not a simple drop-in replacement for most vehicles. You will need to address the wiring requirements, modify your fuel pump module, and potentially add an external check valve. The pump is also priced at around $239, which is premium but justified by the performance.
If you are looking for a more straightforward upgrade that still provides significant performance gains, or if you want the peace of mind that comes with a lifetime warranty, consider KEMSO fuel pumps. They offer direct-fit solutions for many vehicles, deliver improved flow over stock, and are backed by a lifetime guarantee from a USA-based company.
Whichever pump you choose, remember that your fuel system is the lifeline of your engine. Investing in a quality fuel pump is one of the smartest decisions you can make for your build.
For more information on high-performance fuel pumps and to explore your options, visit: