Fuel system layouts:

This is a diagram of a Saloon car race fuel system.


It has a number of unique elements:

- Are you sure about this schematic ? I think it won't 'work' (no pressure diffrence over pressure regulator, so line pressure stays same as pressure generated by fuel pump) -> fuel retun line should be routed to the pump inlet side. Actually swirl pot should also reside inlet side of high pressure pump -> then transfer pump is needed if swirl pot is not inside fuel cell.

[[Manual: Detailed.Output.Fuel.Operate]]

Fuel pumps:

Bosch in-tank pumps from CIS cars is always good and can handle really high fuel pressures. They are usually rated at 5bar. Walbro also has very good in-tank pumps. But always remember to check at which pressure the rated flow is specified.

fuel pump comparison: http://www.stealth316.com/2-fuelpumpguide.htm

The american race type pumps is really tricky and it's usually best to stay far away from them. Some are good and can run forever and some fail all the time. Some have very crappy flow ratings at high pressures too. I have seen an Aeromotive efi pump rated at 700hp chicken out at less then 500hp, when finally finding the flow rating it was 360lbs/hr@45psi. The stock pump in most CIS turbo audis is rated at 169l/h@5bar, that's something like 340lbs/hr@72.5psi. If IRC the Walbro 255l/h flow like the bosch 169l/h pump.

Fuel pressure regulators:

The stock fuel pregulator usually work fine as long as it has a vacuum port (which means it is MAP referenced: constant pressure across injectors). The american race type regulators are usually easier to install if a custom fuelrail is used. Some of them fail once in a while and you should get one that can be rebuilt and get the rebuild kit too if you aren't located in the US.

Fuel pressure regulator can be

fuel pressure regulator upgrades: http://www.stealth316.com/2-fpr_upgrade.htm

TODO: curves: fuel pressure in function of MAP; pressure across injectors and flowrate (which is proportional to squareroot of pressure across injectors) for the 3 types

Rising Rate Fuel pressure regulators:

Normally RR-FPR-s are used by tuners who choose not to install a proper(ly configured) ECM, but stay with the factory ECM that cannot add extra fuel at boost.

Among users of easily configurable ECMs (like GenBoard) constant pressure across injectors and larger injectors are common.

But RR-FPR can also help maintaining a smoother idle for very high performance engines, where idle injector pulsewidth would be very small without lowering the fuel pressure. Injector staging would probably be a better way. Careful configuration is needed in any case, compared to the simple case.

As the RR setup should maintain (does it do fast?) a consistent (but not constant!) pressure across the injectors in function of MAP, the injection control table (j, which is appr. ~VE) can be tuned to consider this (the higher MAP values will be set smaller to compensate for the higher pressure across injectors).

What can make an RR-FPR setup even more sophisticated?

Fuel temperature sensor:

My Range Rover has this sensor on the fuel rail. What is it use for? Taking the density into fuel account, or maybe monitoring the possibility of vapour locks?

[[Manual: Detailed.Output.Fuel.Install]]

Fuel injectors:

See the PortInjected/FuelInjectors page

[[Manual: Detailed.Output.Fuel.Install]]