Industry-Leading Anti-Lag Valves

Industry-Leading Anti-Lag Valves
For high performance engines

Our motto is “Quality Driven Performance” –
performance as a result of quality and attention to detail.

When it comes to high performance racing, it’s the little details that really count, giving drivers and their teams the edge over their competitors to win races and lift trophies. It’s an approach that is built into everything we do at DSPS Engineering because in order to succeed in their field, our clients need instant access to performance, power and reliability.

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Over the years our anti-lag valves have become a critical component in race and championship winning cars in an array of motorsport racing disciplines, with teams taking advantage of almost four decades of motorsport expertise to enjoy a competitive advantage when they need it most.

Our clients remain at the forefront of the industry, using the latest tools and technology to push the boundaries of what anti-lag valves can achieve on race day.

We work closely with our clients to develop long-term relationships and provide bespoke solutions based on their needs and take the time to understand their goals to evolve the product from concept through to manufacture.

At DSPS Engineering we only use the highest quality materials for our anti-lag valves to ensure they can cope with long-term exposure to extreme race conditions.

So, no matter your boost requirement, working together we’ll help you realise the full potential of your engine.

What is an Anti-Lag Valve?

An anti-lag valve is a device used to maintain turbine speed when the throttle is closed or reduced.

Lifting off the throttle, partially or completely will lead to a partial or complete reduction in exhaust gas flow, neither of which is good from a turbine speed point of view, as the turbine is driven by exhaust gas.

If the turbine slows down markedly, application of the throttle will need the turbine to speed up again before full boost is achieved – this takes measurable time and this spooling time is called turbo lag.

An anti-lag valve keeps the turbine spinning, even when the throttle is closed or reduced, allowing for a much more responsive engine when accelerating again.

Anti-lag valves initially found use in Formula One during the 1980s, although changes to fuel regulations meant the component was no longer suitable for the class. However, it soon found favour in rallying as the introduction of mandatory restrictors in the manifold inlet meant cars experienced increased turbo lag, and anti-lag valves provided the ideal solution to for teams to maintain vehicle power.

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What are anti-lag valves used for?

There are two ways in which an anti-leg system (ALS) can work, both providing an air bypass to reduce or compress turbo lag on turbocharged engines, so any lag experienced by the vehicle is minimised as much as possible.

This makes them ideal for a wide range of racing cars, which is why they are so commonly used in rallying to maintain performance.

How do anti-lag valves work?

Anti-lag valves are simple in the way that they work. When the throttle is lifted, signals from the electronic control unit tell the fuel injectors to stop sending fuel into the cylinders, causing the throttle to close. At the same time, exhaust gases are halted temporarily, which isn’t ideal for turbocharged engines as they depend on gases from the exhaust.

Once you get back onto the throttle, it takes a while for the turbocharger to reach velocity and hit boost. The small gap between these two stages is known as turbo-lag.

There are two ways in which an anti-lag system can work, as it depends on the car and system installed. If the ignition timing is adjusted this can create spark within the exhaust as the throttle is lifted.
Alternatively, spark can be induced inside the exhaust manifold by enriching the air/fuel mix.
This ensures that spark occurs when you lift, keeping the turbocharger spooled.

Different types of anti-lag valves

There are two main types of anti-lag valves which we explain in more detail below:

Throttle bypass anti-lag system

To allow a passage of air even when there is no acceleration, the throttle plate is left slightly open. Two key components control this type of system – fuel enrichment and ignition delay.

When the piston is around the top in a standard 4-stroke combustion engine cycle, the ECU will allow ignition, which allows for maximum power generation through efficient burning of fuel.

But where there is a delayed ignition, combustion can only happen when the pistons are heading downwards during the exhaust stroke.

Because extra fuel can be sprayed in by the fuel injector, unburnt fuel is caused by inefficient combustion, which then leads to another combustion because of exhaust gases that are too hot. It’s
this second explosion that creates the right amount of pressure for the spooling of the turbocharger.

Secondary air injection anti-lag system

A secondary air injection anti-lag system is also referred to as a ‘rally-style’ system. Through the addition of a plumbing system before the throttle plate it creates a secondary air injection for the engine.

As the throttle is eased and the plate closes, air is diverted around the engine by the secondary air injection enabling it to reach the exhaust manifold. The flow of diverted air is controlled by either a bypass valve or spring, so once acceleration is initiated the ECU can control the fuel mixture.

A combination of unburnt fuel, high-temperature exhaust gases and extra air create secondary explosions which ensure the turbocharger can continue to spool.

Modern versions of secondary air injection anti-lag systems provide control mechanisms that allow you to manage the anti-lag setting. This means the throttle response can be adjusted by the driver or they have the option to turn it off completely when it’s not needed, which helps to prevent the turbocharger from experiencing high-temperature wear and tear.

Specific types of anti-lag valves

The descriptions above offer a general description of how anti-lag valves work and their benefits.

To give you a better idea of their construction and features, here are some specific examples:

  • 3 Lug ALS valve with Wiggins Inlet
    The 3 Lug ALS valve with Wiggins inlet arrived in 2018 and was inspired by the highly successful single port ALS valve. It features a 33.75mm outlet port that uses 4 tubes with a bore of 12.70mm to feed air into the primaries.
  • Anti-lag valve – single port
    The single port anti-lag valve has been around since 2011 and has remained a successful component used in several championship winning cars in RallyX, WRC, IMSA, WTCC and many more. The device enables air from the compressor or plenum to feed into the primaries using a 30mm outlet port, with cold air fed into the ALS through a Wiggins-style aluminium fitting (23mm bore)
  • Anti-Lag Valve - 40mm Port
    One of the newer valves, the 40mm part anti-lag valve, is derived from the highly popular 30-34mm ALS valve that has been consistently used on race winning cars in RallyX and Rally Championships. Air feeds into the primaries through a 40mm single outlet port, with cold air fed into the ALS through a Wiggins-fitting (42.90mm bore).

Why championship-winning motorsport teams choose DSPS anti-lag valves

DSPS Engineering’s anti-lag valves eliminate lag on gear changes and deceleration while helping to maintain turbine speed. From RallyX to WTCC, IMSA and WRC, our anti-lag valves have helped championship winning cars maximise their performance potential, developing solutions that are based on your vehicle, engine and ECU.

We are constantly looking towards the future, searching for new ways to innovate and evolve anti-lag technology. Motorsport teams trust in our experience and industry-leading knowledge to support their progress season after season, because they know we always deliver first-class results that gives them a platform to succeed.

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Anti-lag system kit closeup