|High horsepower levels demand precisely controlled high fuel flow rate. The APS High Capacity fuel injectors significantly increase the fuel flow rate capacity to the XR6 Turbo engine for maximum performance.
Unlike coarse methods of increasing fuel flow through the standard injectors by increasing fuel rail pressure and/or utilizing inferior pintle style injectors, the APS High Capacity Directional Quad Orifice injectors deliver a precise spray pattern designed for the XR6T's multi-valve head - particularly at high flow rates required to produce in excess of 300 kW of power.
Fuel injectors in general are designed to deliver fuel within a certain range of fuel pressure, duty cycle and volumetric flow rate parameters. When any of these parameters are exceeded, the spray pattern and atomization properties of the fuel being injected degrade rapidly - which is particularly evident with the standard XR6 Turbo injectors. When increasing the fuel pressure in order to force more fuel through the injector nozzles, the resultant spray pattern exhibits a significant degradation in fuel particle size and spread. In addition, in order to supply fuel at a higher pressure, the standard fuel pump is placed under greatly increased load.
Needless to say, poor fuel spray patterns have severe consequences on fuel economy, throttle response and most importantly on engine durability, particularly at high power levels.
There are many ways of increasing fuel flow but only one is technically correct - Appropriately sized injectors operating within the specified injector duty cycle and fuel pressure to achieve the desired power level.
APS offers injectors specifically designed for the XR6 Turbo - in two sizes. These will be available in quanity towards the end of June 2004.
Injector Flow Rates on XR6 Turbo
|Part Number: 695 084 100
Full flow rate capacity - 425 cc/min
Power applications - up to 320 kW
|Part Number: 695 084 200
Full flow rate capacity - 510 cc/min
Power applications - 320 kW to 390 kW
|Adrenalin Injection to the extreme!
Correct Injectors for the Ford XR6T Multivalve Head
The XR6T combustion chamber is fed via a single port that is split to feed each inlet valve. This is a popular design and one that is well proven in terms of performance. A critical factor however is to specify fuel injectors that are correctly configured to inject fuel in the correct spray pattern for this split design.
The pictures above and below show the inlet port in detail. Above, when viewed directly into the port and below off to one side. The central bridge is clearly visible. This is where the main inlet port becomes split into two - one for each inlet valve. The area above the bridge is where the fuel injector nozzle protrudes into the inlet tract. This also happens to be just in front of the bridge.
The correct injector type for this inlet configuration is one where the injector nozzle sprays a precisely split amount of fuel directly into each port and onto the back of each inlet valve - with each stream of equal quantity to ensure even mixture distribution inside the combustion chamber. This type of injector is known as a Directional Multi Orifice injector.
There are a number of different injectors that externally look the same as a directional multi orifice injector, however the spray patterns differ considerably.
The picture above shows three different types of injectors that physically fit the XR6T engine. From left to right:
- Directional Multi Orifice injector which has a split spray pattern suitable for use in the XR6T engine
- Standard Multi Orifice injector which does not split the spray and is designed for a single valve head
- Old fashioned pintle style injector, again with a single spray.
||An Injector Test Bench is used to graphically demonstrate the difference in spray pattern of all three different types of injector - side by side.
Click here to view video
NOTE: Injector Styles
- The APS injectors (shown left) are High Capacity Directional Quad Orifice injectors specifically designed to spray fuel precisely in the Ford XR6T's multi-valve head configuration. This results in not only efficient combustion and optimum engine operation, but also excellent fuel economy and clean emissions. These injectors are very sophisticated and not commonly available in the aftermarket industry.
- Standard Multi Orifice injectors look very similar to the APS injector, however the single spray pattern of these injectors render them unsuitable for XR6T applications - and indeed, any multivalve application. Standard or Non-Directional Multi Orifice style injectors should be avoided at all costs, particularly in high horsepower applications....
- Cheap pintle style injectors (shown right) are commonly available in a variety of sizes. Whilst these injectors may be of an appropriate size, they deliver a very course spray pattern which is not at all suitable for the XR6T engine. These injectors are also of a metal body construction and transfer a significant amount of heat into the fuel - resulting in increased likelyhood of vapour lock. Pintle style injectors should be avoided at all costs, particularly in high horsepower applications....
APS High Capacity fuel injectors are designed to remain well within their performance envelope at high engine horsepower levels - and deliver crisp throttle response, economical cruise and tyre shredding horsepower.