Fuel Delivery Diagrams
The Hyper Racing Technicians highly recommend the installation of a flow-through type fuel delivery system with our fuel injection systems. To view the diagrams of different fuel delivery systems, click on the links below, and a pdf file will open in a new window. There are two pages in each of these documents. View both pages to see all relevant information.
Fuel Delivery Systems
Fuel Delivery Systems are a very important part of the engine's performance and your ability to finish races. The system can be divided up into five main areas:
When it comes to buying fuel line, Hyper Racing strongly recommends the HBS Line and Fittings. The HBS Fuel line is compatible with methanol.
The fuel line generally used on micro sprints is the blue rubber hose manufactured by Earl's, Aeroquip, or a few other manufacturers. They are all essentially the same thing, and they are not compatible with methanol. The blue line needs to be replaced every year. It may last longer, but it is at high risk. The line will eventually break down (gradually and without warning) and cause major problems ranging from clogging fuel filters to causing stuck nozzles. There are many stories out there that state "a friend told me they ran the same line for 3 years and didn't have any problems." Those experiences are more the exception than the norm.
The Fuel Pump
A common failure on the fuel delivery system is the pump. The Hyper Racing technicians and teams have tried many different brands and styles of pumps. None of the inexpensive pumps are rated to pump methanol. On all the inline pumps, the fuel flows directly through the electric motor and bearings.
Cavitation is the formation of gas bubbles in the fuel where the pressure of the liquid falls below its vapor pressure point. When the pump can't pull the fuel in, it creates a vacuum forming gas bubbles, when these gas bubbles collapse it creates a shock wave that destroys the bearings and veins.
Key items that cause cavitation may include:
Turning on the pump without first priming or bleeding the air out of the fuel system
Clogged fuel filter
Clogged inlet of pump (the Walbro pumps have a screen on the inlet that can cause severe restriction)
The pick up inside the tank is suctioned to the side of the bladder, or it is clogged
Pinched fuel line
Shut off valve not turned on or one that vibrated off
If you are turning on your pump and the fuel lines do not have fuel in them, you will need to crack the fitting loose on the outlet side of the pump. You will hear the pump run fast for about 10 seconds, then it will make a lower pitch as the fuel gets up inside the pump. When fuel starts to squirt out of the loose fitting, you can tighten it up.
Many times, the pump will work fine at idle and low fuel demand RPMs/loads, but not be able to keep up at higher RPMs/loads when the engine demands the most fuel. A problem such as this is easily diagnosed by watching the fuel pressure gauge while on the track. If issues with the engine blubbering or breaking up exist, the driver should glance at the fuel pressure gauge during race conditions and notice how far it is from the set point. If it is more than 5 lbs. away from the set point, there may be a faulty fuel pump or restricted fuel filter or pickup.
The Aeromotive Pump has mechanically fastened magnets, which was a previous weak spot for these pumps. With its new redesign (2012), it is now our recommended pump. You must run a -8 (1/2") inlet system to help prevent cavitation. This pump has very high quality bearings and components. Send it to Aeromotive during the off season for inspection, and this pump can last for years. This same pump works both for fuel injection and carburetors. Although it will generate over 70 psi, its flow is no more (well maybe a little) than the pumps many carb guys use.
The Walbro Pump is the most popular, but its life span is very limited. A common issue on the Walbro pump is bearing failure. It becomes obvious when you hear the pump making a squealing sound. This is usually caused by cavitation or just wearing out.
Elements: With our methanol fuel, paper or plastic elements will not work. After a race or two, they will choke off the delivery system to catastrophic results. Stainless steel is the only material that works. You need two filters, a 120 micron before the pump to remove the large particles but still allow good free flow, and a 25 micron between the pump and the fuel rail. If you put the 25 micron before the pump it will cause the pump to cavitate and destroy it rather quickly. The two elements can be identified by closely examining the element mesh, the 25 micron has a finer close knit mesh.
Capacity: Our filter elements are pleated to provide maximum surface area enabling tons of particle entrapment without restriction. 6" long x 2-1/4"O.D. filter bodies provide plenty of storage and house a big element.
Cleaning: The 25 micron filter must be cleaned every 2-4 races and the 120 micron every 4-6 races. If you clean the element with an air hose, blow it from the inside out, the particle swill be on the outside of the mesh. The best (and really the only way for the 25 micron) way to clean your filters is with an ultrasonic cleaner. This is the same thing jewelers use. We sell a low cost Ultrasonic Cleaner and Cleaner Fluid to go with it. Use this cleaner to clean your injector nozzles as well.
The regulator is responsible for controlling a constant fuel pressure between the pump and the regulator. Generally in a two port design, it is placed after the fuel rail. (See our fuel delivery diagrams at the top of this section.) Regulators can be adjusted from low to high pressures by the turn of a set screw, and bypass all the unneeded fuel back to the tank through the return line. A general setting for Hyper Racing fuel injection is 60 psi. Although when we dyno tune each engine we may change the pressure setting. After a dyno session, we ask that you do not change this setting.
The 1/8" NPT port on the front side of the regulator is where a fuel pressure gauge is installed. The small nipple coming off the side of the regulator is merely a vent and needs only to be tightened. We have seen no advantage to tying this into the vacuum lines on the throttle bodies. Viewing the regulator as pictured in the image below, the left port is the inlet and the right port (hidden) is the outlet leading back to the tank tail.
The FueLab regulator can be purchased in three configurations: 2-Port Regulator for Injection, 3-Port for Regulator for Injection, and a 3-Port for Regulator for Carburetors. The two port is the normal regulator we sell on our fuel injection fuel delivery systems. The three port design is used where a dead head style fuel rail is used, like those used on the factory motorcycle engines. The only difference between the carburetor and the injection regulators is the spring inside. The spring is what regulates the pressure "pop off". A light spring will allow low fuel pressures. The carburetor regulators are a three port design since there is no flow-through rail. It utilizes a return line to the tank for the unused fuel.
The Aeromotive regulator comes in a three port design but one side port may be plugged to make it a two port design if needed. It is a fine unit, just more expensive than the FueLab and does not have the two year warranty.
In recent years almost all tracks now mandate a bladder of some sort as a safety zone. When this change occurred, Hyper Racing developed the Fuel Forward Tank Tail System for Alcohol and the Fuel Forward Tank Tail System for Gasoline. This revolutionary tank design keeps the fuel low and forward, two critical areas of focus for optimum chassis handling.
Fuel Forward Tank Tail System features choice of bladder depending on the type of fuel you are running. Alcohol bladder is for alcohol only and gasoline bladder is for gasoline only. Failing to use the correct type of fuel (even if just for flushing) will destroy the bladder. Use our purge tank to safely prepare your system for off season storage.The tank tails with bladder kits come with a -6AN bulkhead outlet, however a -8AN bulkhead is available. If you are using a Walbro or similar pump, the -6AN outlet is used. If you are using an Aeromotive or FueLab pump, a -8AN bulkhead is needed. Keep this in mind when ordering a tank.
An improperly installed pickup hose can cause intermittent, hard to diagnose problems. If you are purchasing a Fuel Forward tank tail with a bladder, it will have the pickup correctly installed but not tightened. All you will have to do is tighten up the pickup and the bulkhead fitting. If you are installing your own pick up, ensure it is long enough to lay on the bottom of the tank and also to make sure the end of the pickup hose cannot suction to the inside wall of the tank. There are two common ways to prevent the pickup hose from suctioning to the inside of the tank. One is to cut the end of the pickup hose in a V shape. The second way is to use a ½” NPT x 3/8” Barbed fitting (Hyper Part # 816-105). Drill four to six ¼” holes in the ½” NPT portion of the fitting. Then insert the barbed section of the fitting into the end of the pickup hose. Either of these two methods for the pickup hose has been found to be very reliable.
Fuel Delivery System Maintenance
Methanol is a very dry fuel with no lubrication properties such as that which is present with gasoline. A white chalky residue remains when the methanol evaporates. The trick is to not let methanol evaporate, keep your fuel system filled with methanol, if you clean a fuel filter, replace it, then turn the pump on and remove all the air from the lines immediately. For more information on fuel delivery maintenance go our fuel injection maintenance page.