Direct to Head Individual Throttle Bodies

Our range of billet Direct to Head Throttle Bodies has been developed for the Motorsport and Modified Car markets. They are designed to release the maximum protentional from the engine without compromise.

The benefits of fitting Individual Throttle Bodies

Individual throttle bodies will improve performance by increasing the amount of air that is available to the combustion process of the engine.  Each cylinder will have its own dedicated throttle valve which is located much nearer, this improves the throttle response of the engine because there is less space between the throttle plate and the inlet valve so are can get to the engine much quicker than with a traditional EFI inlet system.

By mounting the injector closer to the throttle plate and further away from the inlet valve helps the fuel to mix with the air better before entering the combustion chamber. There is a trade-off with low-end torque and emissions which is why these systems are best suited to high-performance track orientated engines.

Direct to head throttle bodies have some distinct advantages over the more traditional DCOE replacement type throttle bodies. The main advantages are that they provide the most direct path for the air to travel with no direction changes needed within the flow path. The inlet length can be reduced for installations. The noticeable benefits are that they produce more power and have a quicker throttle response.

When choosing the size of the throttle bodies that would we best for an engine bigger is not always better.  The size of the throttle affects the speed of the air being drawn into the engine if the throttle is to small the air will become restricted due to friction against the walls of the throttle body, but if the body is too large the air speed will be too slow which will mean the air does not have much momentum so dynamic filling of the combustion chamber will be poor.

The table below shows a good starting point for choosing a suitable throttle size.

Engine SizeIndividual Throttle Size
1.642 mm
1.845 mm
2.048 mm

Depending on the intended engine speed during normal operation it might be beneficial to move up a size if the engine is to sustain high rpm at or above the typical redline of the engine.

All of our throttle body kits can be supplied in a range of throttle sizes, we can also provide custom sizes if your engine would benefit from a non-standard size.

Why Direct to Head Individual Throttle Bodies are better than Carb replacement bodies.

The main advantage of a direct to head setup is that they provide the most direct path for the air to travel with no direction changes needed within the flow path. If you look down the bore of a direct to head throttle set once mounted you can see the back of the inlet valves. This also allows the throttle plate to be positioned closer to the inlet valve improving the throttle response further and allowing the larger inlet bore to be maintained closer to the cylinder head.

Another advance of this method of installation is that the throttle inlet length can be reduced allowing more space for air boxes and increased clearances to bulkheads for compact engine bays. The noticeable benefits are that they produce more power and have a quicker throttle response.

Our range of throttle bodies have a range of key features;

  • Billet Aluminium Throttle Bodies.
  • Direct to head Mounting – removing the need for an intermediate manifold.
  • Spaced to match the cylinder inlets – direct air feed with minimal direction changes.
  • Integrated Injector mounting.
  • Adjustable throttle stops and linkage.
  • Modular Design enables easy customisation, upgrades and allows them to be easily transferable.

Customizable options allow each set to be tailored to meet the requirements of each application.

Customisable / Optional features include;

  • Selection of Throttle Size.
  • Take-offs for vacuum pipework.
  • A Range of trumpet lengths to fine-tune the intake length.

To see our range of Direct to Head throttle bodies have a look at our online store.

If your application is not listed please contact us and we will be happy to help develop a kit that suits your needs within a timely manner. We are always looking to expand our range and offer reductions to those who are prepared to help us develop new kits, if you would like to become a developer and help us with a new kit, then check out our Developer Scheme Page or email info@gradient-engineering.com

Full bespoke solutions are also available for rare or special project engines to extract their maximum potential, for more details check out our Custom Inlets Page

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