AIRTEC Motorsport Cosworth Inlet Plenum Upgrade – Fits 2WD & 4WD

Technical Data

Designed to fit both 2WD and 4WD Cosworth YB engines, our Cosworth YB plenum upgrade has been tried, tested and proven to work.

The improvements in air flow can be seen on any level of power/torque and tune, but the more highly tuned the car is the more you will reap the benefits.

How it works
The original inlet plenum does not distribute flow evenly across all four cylinders, as the design naturally favours the two centre cylinders closest to the plenum’s entry point. This creates a restriction to overall flow but also means each cylinder has a different amount of air flowing through it, which can affect cylinder temperatures, creating ‘hotter’ cylinders that are more likely to create issues.

By creating an improved plenum design that provides even flow across all four cylinders using internal diffusers to help divide and direct air, the inlet manifold sees more equal amounts between cylinders.

The effects of even flow distribution means less restriction and therefore improved throttle response as well as power/torque increases, with the most noticeable gains found after mapping to accommodate the change in flow characteristics in comparison to the original plenum. As flow is improved, the higher the power, the higher the benefit and the plenum design has been tested to give as much as 45bhp during back-to-back testing. It has also been tested to provide lower and more equal Exhaust Gas Temperatures across the cylinders, which makes for a happier, healthier engine.

What’s Included?
The cast aluminium plenum is finished in natural silver and is drilled to fit the original 2WD or 4WD throttle body. It comes with O-rings to seal the manifold flange and throttle body and there is an optional throttle cable bracket and throttle body butterfly lever available as options if required.

There is also an option to add a custom fluoro-lined power steering hose to clear the throttle body, which is ONLY required if you have an earlier Cosworth engine with the power-steering pump mounted directly below the throttle body and the pipe pointing upwards.

Features:

• Proven and tested to work – evenly distrubtes flow across cylinders
• Internal diffusers ensure air is diverted and directed equally
• Gains in power and torque – becomes even more effective the higher the power
• Evens out differences in cylinder tempertures, so there are no ‘hot’ cylinders
• Strong alloy casting that will not split under high boost pressure
• O-ring gaskets on throttle body and main manifold flanges included in kit

AIRTEC Part No: ATMSFO29