You might have heard of turbo engines and how it helps engines gain extra power. Turbocharger depends on engine exhaust to generate more power. The exhaust needs time to build up enough output to drive the turbocharger.
This means when your car slows down, upon acceleration there will be a delay to throttle response. The time needed for change in engine output on throttle response is referred to as turbo lag.
The problem is more apparent in racing applications when you require rapid changes to engine power output. To avoid turbo lag you need to maintain the engine rpm, which is not possible unless you are on a racetrack.
One of the ways to overcome such problems is to use an anti-lag system in cars.
Working of Turbocharger
To understand how the anti-lag system works, let’s refresh a bit about the working of the car turbochargers. A turbocharger has a compressor wheel and turbine wheel connected by the same shaft in a housing.
The turbine inlet is connected to the exhaust port of the engine. As the exhaust gases pass through the port, the turbine wheel rotates while forcing the compressor wheel to rotate as well. This allows the compressor wheel to draw in air to inject back into the engine for more power output.
Car anti-lag System (ALS)
If the exhaust gases are not enough, it leads to turbo lag as throttling the engine needs time to build exhaust output.
Car anti-lag system reduces or eliminates turbo lag by making a few adjustments. The anti-lag system uses fuel with exhaust gases to cause combustion due to high temperature in the exhaust manifold. The extra force from the explosions keeps the turbocharger moving even when the engine slows down.
In addition to the anti-lag system, find out the difference between regular and racing car oil to use improve the performance of your race car by using the right option.
Types of Car anti-lag System
There are various ways to install a car anti-lag system. The common types includes:
- Throttle Bypass
- Secondary Air Injection
Throttle Bypass anti-lag System
In the throttle bypass anti-lag system, the throttle plate remains slightly open to allow passage of air even when not accelerating. The system relies on two key components, ignition delay and fuel enrichment.
In a standard 4-stroke combustion engine cycle, the ECU allows ignition when the piston is around the top. This leads to efficient fuel burning with maximum power generation. However, in a delayed ignition, the combustion occurs when pistons are on the way downward during the exhaust stroke.
Since the ECU allows fuel injector to spray in extra fuel, inefficient combustion results in unburnt fuel that causes another combustion due to high-temperature exhaust gases. The secondary explosions create enough pressure to maintain the spooling of the turbocharger.
Secondary Air Injection anti-lag System
Also known as the rally-style anti-lag system, the method relies on creating a secondary air injection by adding a plumbing system before the throttle plate.
When legs are off the pedal and throttle plate close down, the secondary air injection diverts the air around the engine and sends it to the exhaust manifold. Where a spring or bypass valve controls the flow of diverted air, the ECU controls the rich fuel mixture during the deceleration.
Extra air, unburnt fuel and high-temperature exhaust gases result in secondary explosions to keep the turbocharger spooling.
Modern secondary air injection anti-lag systems provide options to control the anti-lag setting via control knobs. Drivers can adjust the throttle response or switch it off to prevent high-temperature wear and tear of turbochargers when not needed.
Two-Step Launch Control
Two-step launch control or rev limiter is not basically an anti-lag system. However since it uses a similar principle, they are often confused with the car anti-lag system (ALS). As the name suggests, the two step rev limiter has two stages of rev limiter.
The first limiter is set at lower rpm, known as launch control. This is to prevent high speed cars from reaching redline during a launch. This minimises the wheel spin off and gives the car optimal traction on launch. The second rev limiter is set around the red line to prevent excessive vibrations and damage to engine components.
Just like car anti-lag systems, two-step rev limiter also relies on delayed ignition timings. As the spark plug ignites the fuel later to keep up with the first rev limiter, the unburnt fuel causes a secondary explosion to give an extra boost.
If the car happens to have a turbocharger, it might give an added boost but not like a car anti-lag system that is designed specifically for turbochargers. Also, learn about what causes turbocharger failure to avoid such a hazard.
FAQs
Is the anti-lag system bad for cars?
Car anti-lag system puts extra pressure and stress on the turbocharger due to high temperature explosions. Although turbochargers are designed for durability, they are not manufactured to bear continuous explosions. This limits its application to race or drag cars.
Is the car anti-lag system the same as two step?
Although both car anti-lag system and two step rev limiter works on similar principle by delaying ignition timing. The ALS is specifically used in turbo engines to maintain the speed. Whereas the two step rev limiter sets the rpm for best launch and can be incorporated with a turbo engine to offer anti-lag capabilities.
Since the car anti-lag system can damage your expensive turbocharger, it does not come factory fitted by the manufacturers. However, its ability to keep the turbo spooling while cornering, makes it a prime choice for race applications. In fact, the car anti-lag system is responsible for flaming exhaust due to secondary explosions of unburnt fuel.
Car modifications in the UAE require permission from relevant authorities. Without permission, engine modifications can result in fines and confiscation. One such regulated modification for racing cars is the use of Nitrous Oxide in cars.
Modifying a new car is usually not a preference as many would like to maintain the factory setting for resale value. Therefore, it’s a good idea to use a used car for this purpose. Explore your options with used cars for sale in the UAE to find some good deals.
Stay tuned to the UAE’s leading auto blogs for more information on car parts, market trends and automotive technology.
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