All About Fuel Pumps, Updated January 2021

INTRODUCTION
At Radium Engineering we design our surge tanks and fuel pump hangers around popular aftermarket fuel pumps from Walbro (aka Ti Automotive) and AEM. We have chosen to offer the highest performing pumps from the most reputable companies.
This article will describe each pump and provide information so you can choose the right pump (or pumps) for your application.


WALBRO F90000-SERIES FUEL PUMPS
Due to Ti Automotive's COVID related production issues in 2020, these pumps are often out of stock. Please contact Radium Engineering before purchasing to check stock.
Lets start with our most popular offering, the Walbro F90000-series pumps, officially called Ti Automotive 39/50 DCSS pumps. These gas/E85 compatible pumps have a stepped body and come in different flow rates depending on part number.
These are tricky to talk about because many people use the unofficial slang names given to these pumps, such as the "Hellcat pump" or the "Walbro 450" etc. These names rarely have anything to do with the actual flow rate of the pump and often just cause confusion. Here at Radium Engineering we call these pumps by their official F90000... part number, stamped right on the side of them, as shown below.
Ti Automotive has released many F90000-series pumps to the aftermarket over the years, but we are only going to focus on the three most popular: F90000274, F90000285 and F90000295

All of the F90000-series pumps have the same physical dimensions and same electrical connector, so they can be interchanged with each other in Radium products.

The "274" and "285 both have internal check valves, so they can be staged when using more than one in a surge tank or hanger. The "295" does not have a check valve (hence the higher flow) so line pressure immediatly drops when it turns off and it cannot be staged with other pumps, but it works great as a lift pump.
Radium Engineering only offers the F90000274 pre-assembled into products. If you would like to use the F90000285 or F90000295, select the Radium product version "pumps not included" and purchase the pumps you want to use separately.
In-house back-top-back testing of the three F90000-series pumps here at Radium Engineering resulted in the following performance curve:

The F90000285 outflows the F90000274 by about 8%, but requires about 15% more electrical current (more heat!). So only use the F9000285 if you absolutely have to in order to avoid excess heat going into the fuel.
Note that our test numbers are not a direct match to what TI Automotive advertises. This is due to different testing methods and conditions. Also, as pumps wear in, they generally increase in flow rate. This chart does provide a good back-to-back comparison of the pumps though.

The chart above shows how much current each pump uses when operating at 13.5VDC. The F9000285 is drawing considereably more current than the other pumps, this is where it's higher flow rate is coming from. Plan your wiring accordingly.

These pumps have a pressure relief valve setting of about 110-112 psi.  This means that if fuel pressure exceeds this value, a valve will open on the pump and let out excess fuel to keep the pump from hurting itself.



AEM E85 PUMPS
Advanced Engine Management (AEM) has been around a long time and is very well known in the aftermarket and motorsports industry. Their fuel pumps offer a lot of performance and value. The pumps are made to AEM's exact specifications, which are the result of many hours of R&D and countless hours of testing.
We are often asked "Because it is an E85 pump, does it work with gasoline?"  YES! It is compatible with gasoline and alcohol fuels. It even states this right on the side of the pump. These pumps flow 340LPH at 40psi and come in two heights. The size of these pumps mimics popular OEM fuel pumps sizing, so they can swapped into many cars without much work.


WALBRO GSS342
This tried and true option from Walbro is economical and effective. These pumps are great for vehicles with lower power output. This pump draws less electrical current, which helps keep fuel temps lower. However, this pump is not quiet. It is also not officially rated for use with E85, however historical data has shown that it does work fine with alternative fuels.


TI AUTOMOTIVE BKS1000
There is a new king on the block. This brushless pump system is a great option for high power vehicles. Brushless pumps creates a lot of flow without using much electrical power. This helps keep fuel temps and electrical load on the alternator low. Because of the popularity of this option, Radium has been intgrating this pump into new product designs.
A brushless pump always needs a controller. In this case, the controller is a separeate device that sits outside the fuel tank. Four wires connect the controller to the pump. This controller is not programmable in any way, which keeps its complexity and price down. Power is fed into the controller through the red and black wires.


The pump itlsef is called an E5LM. This was previously used in some supercars and high-end SUVs. It is the same 39mm diameter as the other pumps on this page, but it is quite a bit longer. This makes packaging difficult and requires unique designs for many Radium products.

BKS1000 IMPORTANT NOTES:
1. The outlet of the pump DOES NOT HAVE A CHECK VALVE! So you must be careful if planning to stage this with other pumps.
2. The system is only sold as pump + controller. It is not possible to buy only a pump or only a controller.
3. One controller per pump, you cannot use one controller for multiple pumps.
4. The controller can be run with up to 18VDC. As voltage increase, so does pump speed and output. 
5. When run at 18 volts, this pump puts out 26% more flow than it does at 13.5 volts.
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SO WHICH PUMP DO I CHOOSE?

Selecting a fuel pump is based entirely on two factors: Fuel Type and power goal. Make sure the pump is compatible with your fuel type and that it flows enough to meet your horsepower goal (plus 20% or so safety factor). The table below can be used an approximate guide for selecting a fuel pump based on the power output of the engine. For multiple fuel pumps, just multiply the horsepower number by the number of pumps. The actual horsepower values achieved can vary greatly between different types of engines, so use this guide as a general approximation. Rotary engines should not use this table.


This chart shows flow rate vs. pressure for these popular pumps:


If noise is something that you are worried about, this chart compares pump noise. Each reading was taken under identical circumstances back-to-back.



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