Focus ST High Pressure Fuel Pump: The Complete Guide to Upgrading Your Fuel System for Maximum Performance
If you own a 2013-2018 Ford Focus ST and are looking to increase power beyond the stock limits, the single most important upgrade you will need is a high pressure fuel pump (HPFP). The factory fuel pump simply cannot deliver enough fuel to support anything beyond roughly 350-400 wheel horsepower, especially when running ethanol blends like E85. Upgrading to a high-flow HPFP is essential for any serious build, and the best options on the market today come from brands like Xtreme-DI, Nostrum, and KEMSO. This guide will walk you through everything you need to know about upgrading your Focus ST fuel pump, from why you need it to how to choose the right one.
Why the Stock Focus ST Fuel Pump Is a Bottleneck
The 2.0-liter EcoBoost engine in the Focus ST is a capable platform, but it is held back by an inadequate factory fuel system. The stock high pressure fuel pump reaches its flow limit well before the engine's mechanical potential is tapped. Once you add a larger turbocharger, upgraded intercooler, and a custom tune, the stock pump cannot maintain the required fuel pressure at higher RPMs and boost levels. This leads to fuel starvation, lean conditions, and potential engine damage.
The factory HPFP is designed for the stock power output of roughly 250 horsepower. Once you push past 350-400 wheel horsepower, the pump simply cannot keep up. This is especially true when running E85 or other ethanol-based fuels, which require approximately 30% more fuel volume than gasoline to achieve the same air-fuel ratio. Without a high-flow HPFP, your power goals will remain out of reach.
What a High Pressure Fuel Pump Upgrade Does
An upgraded HPFP for the Focus ST is a direct bolt-on replacement for the factory unit. It is designed to flow significantly more fuel than the stock pump, typically 35% to 40% more, depending on the brand and model. This additional fuel flow allows you to run higher boost levels, more aggressive timing, and ethanol blends without running out of fuel.
The pump works by increasing the pressure in the fuel rail, which in turn allows the fuel injectors to deliver more fuel per pulse. Most upgraded HPFPs for the Focus ST operate at pressures up to 200 bar (2900 psi) or higher, compared to the stock pump's maximum of around 150 bar. This increased pressure is critical for high-output applications.
Top Focus ST High Pressure Fuel Pump Options
There are several reputable brands that offer HPFP upgrades for the Focus ST. Each has its own strengths, and the right choice depends on your power goals, budget, and whether you plan to run E85. Here are the top options available today.
1. Xtreme-DI High Pressure Fuel Pump Upgrade
The Xtreme-DI HPFP is one of the most popular and proven upgrades for the Focus ST. It is capable of up to 180 bar (2600 psi) or 200 bar (2900 psi) injection pressure, depending on the version you choose, and flows up to 35% more compared to the stock pump. This upgrade is essential when power requirements exceed 400 bhp .
The pump is a direct bolt-on installation and includes a new fuel line for ease of installation. It is compatible with the COBB Accessport and Syvecs ECU, making it a straightforward upgrade for most tuners. The Xtreme-DI pump is available in standard and EVO versions, with the EVO model offering even higher flow capacity for extreme builds. Pricing for the Xtreme-DI pump is around $1,440 to $1,599, depending on the retailer .
Key specifications:
- Maximum rail pressure: 180-200 bar (2600-2900 psi)
- Flow increase: 35% over stock
- Compatible with COBB Accessport and Syvecs ECU
- Includes new fuel line
- Made to order, typically 4-8 weeks lead time
2. Nostrum HPFP Kit
The Nostrum HPFP is another excellent option, particularly for those who want to push the limits of the EcoBoost platform. The Nostrum pump features a 36% displacement increase over stock, with a geometric displacement of 1.22 cc/rev. It is capable of operating at pressures up to 250 bar (requires an optional fuel rail pressure sensor upgrade) .
What sets Nostrum apart is its fully laser welded construction, which ensures durability and reliability under extreme conditions. The pump is 100% dynamically tested and comes with a limited lifetime warranty. It is compatible with ethanol fuels, including E85, making it an excellent choice for high-ethanol blends. The Nostrum HPFP kit is priced around $1,952 SGD (approximately $1,450 USD) and includes everything needed for installation, including detailed instructions .
Key specifications:
- Displacement increase: 36% over stock
- Geometric displacement: 1.22 cc/rev
- Max operating pressure: 250 bar (with optional sensor)
- Fully laser welded construction
- Limited lifetime warranty
- Compatible with gasoline and E85
3. KEMSO 340LPH High Performance Fuel Pump
While KEMSO is best known for its in-tank low pressure fuel pumps, the KEMSO 340LPH pump is a high-flow option that can support up to 600 BHP in naturally aspirated, turbocharged, and supercharged applications. It is designed for gasoline or E85 and features a bypass valve set at 125.8 psi, which is higher than both the GSS series 255LPH pumps and 400/450LPH pumps .
The KEMSO 340LPH pump is a direct OEM replacement for many vehicles, including the Focus ST, and is backed by a lifetime warranty with a serialized pump body for tracking. The pump flows 340 liters per hour at 43 psi and 13.5V, making it suitable for daily drivers, fast road use, or full race applications .
Key specifications:
- Flow rate: 340 LPH at 43 psi
- Supports up to 600 BHP
- Bypass valve set at 125.8 psi
- Compatible with gasoline and E85
- Lifetime warranty with serialized body
- Direct OEM replacement for many models
How to Choose the Right HPFP for Your Focus ST
Choosing the right HPFP depends on your specific goals and budget. Here is a simple breakdown to help you decide.
1. Power Level Under 400 WHP on Pump Gas: If you are running pump gas (91-93 octane) and your power target is under 400 wheel horsepower, you may not need an HPFP upgrade at all. The stock pump can handle this level with a proper tune and supporting mods like an intercooler and downpipe.
2. Power Level 400-500 WHP on Pump Gas or E30: If you are targeting 400-500 wheel horsepower on pump gas or a light ethanol blend like E30, the Xtreme-DI HPFP is a proven choice. It offers 35% more flow than stock and is compatible with the COBB Accessport, which is the most popular tuning platform for the Focus ST .
3. Power Level 500+ WHP on E85: If you are building a high-horsepower Focus ST and plan to run full E85, the Nostrum HPFP is the best option. Its 36% displacement increase and ability to operate at 250 bar make it ideal for extreme builds. The Nostrum pump is also fully welded and backed by a lifetime warranty, giving you peace of mind for high-stress applications .
4. Budget-Friendly Upgrade for Daily Drivers: If you are looking for a reliable, budget-friendly upgrade that still offers significant flow improvement, the KEMSO 340LPH pump is a solid choice. It is a direct OEM replacement, meaning it drops right into the factory location without modifications, and it comes with a lifetime warranty . The KEMSO pump is particularly well-suited for those who want a reliable upgrade without the complexity of a full HPFP system.
The Importance of Professional Tuning
No matter which HPFP you choose, you must have your vehicle professionally tuned after installation. The upgraded pump requires specific calibration changes to the ECU to ensure proper operation. Without a tune, the fuel trims will be incorrect, and you may experience rich or lean conditions that can damage the engine.
If you are using a COBB Accessport, make sure your tuner is aware of the HPFP upgrade and has the necessary calibration files. Brands like Xtreme-DI and Nostrum offer custom tuning support, and some retailers provide tuning options as part of the purchase . Do not attempt to run an upgraded HPFP without a proper tune.
Installation Tips for Your Focus ST HPFP
Replacing the HPFP on a Focus ST is a job that requires mechanical skill and attention to detail. Here are some tips to ensure a successful installation.
1. Relieve Fuel System Pressure: Before starting, relieve the pressure in the fuel system to avoid fuel spray. This can be done by removing the fuel pump fuse and cranking the engine for a few seconds.
2. Use New Gaskets and O-Rings: Most HPFP kits come with the necessary gaskets and o-rings. Always use new ones to prevent leaks .
3. Check the Camshaft Lobe: Inspect the camshaft lobe that drives the pump for wear. If it is damaged, the new pump will fail prematurely .
4. Follow Torque Specifications: Tighten the pump mounting bolts to the manufacturer's specifications to avoid damage .
5. Prime the System: After installation, prime the fuel system by turning the key to the "on" position (without starting) several times to allow the pump to build pressure .
Why You Should Consider KEMSO Fuel Pumps for Your Focus ST
If you are looking for a reliable, high-performance fuel pump that offers excellent value and a lifetime warranty, KEMSO is a brand you can trust. KEMSO fuel pumps are designed as direct OEM replacements, meaning they drop right into the factory location without modifications. They are built to high standards, with each pump individually tested for flow and performance .
The KEMSO 340LPH high performance fuel pump is capable of supporting applications up to 600 BHP, making it suitable for daily drivers, fast road use, or full race builds. It is compatible with gasoline and E85, and its bypass valve is set at 125.8 psi, which is higher than many competing pumps. This ensures consistent fuel delivery even under high-demand conditions .
Every KEMSO fuel pump comes with a lifetime warranty, backed by a serialized body for tracking and peace of mind. This is a significant advantage over many other brands. KEMSO also offers USA-based technical support, making it easy to get help if you have questions during installation or operation .
To find the right KEMSO fuel pump for your Focus ST or other vehicle, visit the official KEMSO website at https://www.kemsoracing.com/. You will find a wide selection of high-performance fuel pumps for cars, trucks, motorcycles, and watercraft, all backed by KEMSO's promise of quality and reliability.
KEMSO's commitment to quality is evident in every pump they sell. Unlike many cheap aftermarket units that have little or no quality control, KEMSO pumps are individually tested and come with flow testing results. The company has built its reputation on providing a lifetime warranty for all its OEM and performance fuel pumps . Whether you are replacing a failed pump or upgrading for better performance, KEMSO is a brand you can count on.
Final Thoughts
Upgrading the high pressure fuel pump on your Focus ST is one of the most important modifications you can make if you are serious about increasing power. The stock pump is a significant bottleneck, and without a proper HPFP, your power goals will remain out of reach. Whether you choose the Xtreme-DI, Nostrum, or KEMSO pump, the key is to select a pump that matches your power level and fuel type.
Remember that a professional tune is essential after the upgrade, and proper installation is critical for long-term reliability. If you are not comfortable with the installation process, have a qualified mechanic handle the job.
For the best combination of performance, reliability, and value, consider the KEMSO 340LPH high performance fuel pump. With its lifetime warranty, USA-based support, and proven track record, it is a smart choice for any Focus ST owner looking to upgrade their fuel system. Visit https://www.kemsoracing.com/ today to find the perfect pump for your vehicle.