Fuel pump technology is ever-changing and has been crucial to the automotive industry for the last hundred years. Fuel pumps were created in the late 1800's to simply solve a safety problem.

Since then, they have grown into a subcategory, and people often debate the merits of traditional period-correct pumps versus the newest generation of high-performance pump options. We’ll go into the history of fuel pumps and what options are currently available, whether traditional or high-performance style.

• Where Fuel Pump Technology Began
• What Is Traditional Fuel Pump Technology?
• The Electric Fuel Pump Revolution Begins
• Electric Fuel Pumps & Fuel Injection Become the Standard
• Fuel Types and Their Effect on Fuel Systems
• Incorporating High-Performance Fuel Pumps for a Specific Purpose

Where Fuel Pump Technology Began

We love walking through car shows and automotive museums. As a fuel technology supplier, we can see the history and evolution of fuel systems through the generations of cars and trucks on display. Fuel system technology was extremely basic when automobiles were first built over 150 years ago. A tank close to the engine bay stored the fuel, typically positioned higher than the engine to allow gravity to help the fuel flow from the tank to the engine.

While the design was simple, it was also problematic concerning safety for the passengers in the car. The term “firewall” came from the need for a barrier preventing fire from reaching passengers in the car. After numerous issues with this dangerous mounting location, engineers relocated the fuel tank to the rear of the car. At that point, a mechanical pump was added to move the fuel to the engine.

What Is Traditional Fuel Pump Technology?

When an engine sits for a while, it loses the suction or vacuum within the fuel system, and it takes a few revolutions of the engine to build enough vacuum to draw fuel back to the engine again. This is why older cars and trucks take longer to start, and it sounds like they just crank and crank before starting the engine. The mechanical pumps only operate at a low pressure between 4 and 6 psi, so it doesn’t take long for the system to pressurize and deliver fuel to the engine.

The mechanical pumps are simple and reliable, but they can be susceptible to vapor lock due to overheating the fuel. Outside temperatures or excessive temperatures in the engine bay can quickly cause the fuel to turn from liquid to gas and stall an older car or truck. This is one of the major drawbacks of the “traditional” system and one of the many reasons we now have better technology.

The Electric Fuel Pump Revolution Begins

Carburetors were the dominant fuel delivery method when mechanical fuel pumps were added to automobiles in the 1920s, but the concept of fuel injection was invented in 1925 by a Swedish engineer named Jonas Hesselman.

From the 1920s to the late 1960s, many manufacturers did not adopt fuel injection because gasoline was cheap, emissions standards were lax or non-existent, and most car owners didn’t worry about fuel economy. Advertisements of the time showcased style and horsepower as the selling features, but that started to change in the latter half of the 1960s when the market began to adjust due to the rising cost of gasoline and new fuel emission and economy ratings.

A Changing Economy & New Regulations

In the late 1960s and early 1970s, fuel injection started to trickle into the market. The changing market required better fuel economy and lower emissions, which a fuel injection system could provide. The industry produced a new electric fuel pump to meet the high-pressure requirements of a fuel injection system.

Electric high-capacity fuel pumps can generate pressures up to 100psi, which is beyond the normal operating range of 45-65psi of most standard fuel injection systems. Generally, 60psi of pressure can atomize fuel as it travels through the injectors into the engine cylinders.

The electric fuel pump uses a solenoid to actuate a diaphragm and pressurize the fuel system. Some pumps run continuously, while others just cycle on and off when the system needs more pressure to deliver fuel to the engine. This doesn’t allow the fuel to overheat and vapor lock.

Electric Fuel Pumps & Fuel Injection Become the Standard

Electric fuel pump technology and fuel injection gained popularity over the mechanical fuel pump technology and carburetor, and by the mid-1990s, almost every car and truck on the road had fuel injection systems. Early fuel injection systems had two different types adopted by auto manufacturers: internal mixture formation and external mixture formation.

Internal Mixture Formation

There are two categories of internal mixture formation: indirect and direct injection systems. The most common system used, regardless of variety, is the common-rail injection system that uses multiple fuel injectors on a common (i.e., one) fuel rail that supplies fuel to each injector. Indirect systems spray the fuel outside of the combustion chamber and allow the engine to pull the air-fuel mixture into the combustion chamber when the intake valve opens. A direct system injects the fuel into the combustion chamber, where it mixes with the air that rushes in with the opening of the intake valve.

External Mixture Formation

External mixture formation uses manifold injection, which has two different types. Multi-point injection, also called port injection, uses multiple injectors to spray the atomized fuel into the individual manifold runners, where it mixes with air before entering the combustion chamber.

Single-point injection, also known as throttle-body injection, uses just one injector to spray atomized fuel into a centralized area before it is distributed to each engine cylinder. Early gasoline fuel injection adopted the single-point injection model as it was a far cheaper method for automakers to comply with the strict regulations of emissions.

Most American cars and trucks made from the early 1980s to the mid-1990s used single-point injection, while European cars used it mostly in the early 1990s. As the 2000s dawned, multiple-point injection systems became the norm as they offer better drivability and tighter emissions than carburetors or single-point injection systems. This also allows fuel pumps to jump from the early adopted simple units to what we have available today for high-performance options covering multiple fuel types and flow options.

Fuel Types and Their Effect on Fuel Systems

Over the last 30 years, fuel systems have become more complex due to the different fuel types available, the various injection types, and the strict emission standards that must be met in the global markets.  Diesel fuel is mostly sold with two distinctions: off-road and low-sulfur (or on-road) variations.

These don’t require significant changes in the fuel system for diesel automobiles or equipment. As a fuel system supplier and manufacturer, the largest challenge we face is staying ahead of gasoline and fuel pump technology.

The amount of ethanol in a gasoline mixture categorizes it into one of four typical categories: non-ethanol (also called E0), 10% ethanol (E10), 15% ethanol (E15), and 85% ethanol (E85). Gasoline with 10% ethanol is the standard across America; non-ethanol and E85 are available in some markets, and the 15% ethanol variety is available in some regions around the world.

Using gasoline with 10-15% ethanol mixed in doesn’t require significant changes in the fuel system, but incorporating 85% ethanol requires ~40% more fuel flow and components that are resistant to the effects of the corrosive alcohol.

Incorporating High-Performance Fuel Pumps for a Specific Purpose

Most replacement fuel pump kits are designed to only meet the fuel supply requirements of the pump being replaced. They don’t incorporate additional features, nor do they offer additional fuel flow beyond the specified amount for the application.

If you plan to use a different fuel type, such as switching from E10 to E85 gasoline or from gasoline to methanol, you will need to design a fuel system that can accommodate the specific purpose requiring the change.

We field a lot of questions on how to convert a current E10 fuel system to a flex-fuel or E85 system. Using E85 gasoline does have some advantages in terms of engine performance, but it does come with drawbacks, too. A fuel system designed to incorporate 85% ethanol must flow at least 30-40% more fuel for a naturally aspirated engine. If your engine uses forced induction via a supercharger or turbocharger, switching to E85 may require even more fuel flow.

Upgrading Your Fuel System

If your goal is to add more horsepower and torque to your vehicle, a larger fuel pump will allow for more volume but you will still need to replace additional fuel system components to ensure the system is running efficiently. Beyond the fuel pump, larger injectors, and computer re-flash to control the changes, you should add other supporting components that will flow the required fuel amount to meet your goals.

If your vehicle has a fuel pump that is rated at 100LPH (liters per hour), you may choose to replace it with a 255LPH pump instead of the minimum 155LPH pump E85 will require. You can also increase the size of the fuel injectors equally, plus replace your fuel pressure regulator, fuel filter, pressurized fuel line, return line, and the fuel pump wiring for the extra required fuel flow.

Quantum Fuel System High-Performance Fuel Pump Options:

pART NUMBER	PART DESCRIPTION	APPLICATION NOTES	HORSEPOWER SUPPORT
QFS-344FT	265LPH E85 IN-TANK EFI FUEL PUMP	Universal	500
QFS-342FT	340LPH E85/FLEX IN-TANK EFI FUEL PUMP	Universal, can be doubled for 900+ hp	640
QFS-343FT	340LPH E85 INTANK FUEL PUMP	Universal	640
QFS-350FT	340LPH E85/FLEX IN-TANK EFI FUEL PUMP	Universal	640
QFS-353FT	340LPH E85 INTANK FUEL PUMP	Universal	640
QFS-450FT	450LPH E85/FLEX IN-TANK EFI FUEL PUMP	Universal	840
QFS-525FT	QFS 525LPH E85 COMPATIBLE IN-TANK FUEL PUMP	Universal	900
QFS-606FT	380LPH INLINE EXTERNAL E85 FUEL PUMP	Universal, external mounting	716

Switching to E85 gasoline isn’t the only way to achieve higher horsepower. Some systems incorporate methanol injection into the gasoline-based fuel system, while others use methanol, an alcohol blend, or nitromethane as the main fuel type for a specific environment like drag racing.

These systems may use a smaller fuel cell to save weight, but they can still incorporate a similar style pump setup with an electric in-tank fuel pump. Some systems may also incorporate a surge tank that acts as an on-demand fuel supply when the engine draws more fuel than the pump can keep up with in a short period.

Want to learn more about switching to E85 and how fuel pump technology has adapted to accommodate the higher ethanol levels? Read our FAQ: Convert to E85 Fuel

More Horsepower, More Fuel

Engine technology continues to evolve and create better components to achieve higher levels of horsepower. Some of our customers have successfully installed 2 and 3-pump systems using our 450LPH fuel pump to support over 2,000 horsepower from the engine.

The flow rate for that amount of horsepower is incredible, but even high-performance electric fuel pumps have a limit to pumping fuel. Power requirements beyond 2,000 – 3,000 horsepower may need to revert to a mechanical pump, which takes us back in time and technology.

Want to Chat About Your Upcoming Fuel Pump Installation?

We are available Monday through Friday, 7:00 a.m. to 4:00 p.m. PST, over the phone or through our extensive catalog. Be sure to contact us via our support page for any detailed technical questions, and we’ll get back to you as soon as possible.