What is engine torque and how to increase it(modify)

Engine torque refers to the twisting force produced by an engine’s crankshaft, which is used to rotate the vehicle’s wheels and propel it forward. Torque is an essential factor in determining an engine’s ability to perform tasks like accelerating, towing, and climbing hills. It’s often measured in units like Newton meters (Nm) or pound-feet (lb-ft).

Imagine you’re riding a bicycle up a steep hill. As you pedal, your leg muscles force the pedals, causing them to rotate. This force generates a twisting motion at the crankshaft, which is connected to the bicycle’s chain and ultimately turns the wheels. The force you’re applying to the pedals is analogous to the engine torque in a vehicle.

Now, consider two different scenarios:

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Scenario 1: Riding with Low Torque


In this scenario, you’re riding a bicycle with a low gear ratio. This means that for each pedal revolution, the wheels also make several revolutions. While this allows you to pedal comfortably at a high speed on flat ground, it becomes challenging when you encounter a steep hill.

When you start climbing the hill, you’ll notice that it’s difficult to maintain a steady speed, and you might even have to stand up and pedal with more force to keep moving. In this case, the twisting force (torque) you can apply to the pedals is limited, making it harder to conquer the hill.

Scenario 2: Riding with High Torque


Now, imagine you switch to a much lower gear ratio on the bicycle. With each pedal revolution, the wheels only make a fraction of a circle. As you approach the same steep hill, you’ll find that it’s much easier to maintain a steady speed. You can pedal more slowly and with less effort while still making progress up the hill. This is because the lower gear ratio allows you to apply more twisting force (torque) to the pedals, which is translated into greater wheel-turning force.

In this scenario, you have increased torque at your disposal, making hill climbing more manageable.

Similarly, vehicles use engine torque to overcome resistance, such as the weight of the vehicle itself, air resistance, and the slope of the road. A higher torque output from the engine allows the vehicle to accelerate more effectively, tow heavy loads, and handle challenging terrains like hills and rough roads.

Does torque matter to increase vehicle speed?

Yes, torque is a crucial factor in increasing vehicle speed. While horsepower and torque are often discussed together, they play distinct roles in determining a vehicle’s performance, including its speed.

Torque is the twisting force generated by the engine’s crankshaft. It’s responsible for initiating and maintaining rotational motion, which is transmitted to the vehicle’s wheels through the transmission and drivetrain. When you press the accelerator pedal, the engine produces a torque that is used to overcome resistance (such as friction, air resistance, and the vehicle’s weight) and propel the vehicle forward.

Accelerate quicker

At lower speeds, especially during acceleration from a standstill or at low RPMs (revolutions per minute), torque is particularly important. A higher torque output enables the vehicle to accelerate more quickly because it can overcome the initial inertia and resistance. This is why vehicles with higher torque tend to feel more responsive during city driving and stop-and-go traffic.

Aerodynamics and the power

However, at higher speeds, other factors come into play, such as aerodynamics and the power required to overcome air resistance. This is where horsepower becomes more relevant. Horsepower is a measure of the engine’s ability to do work over time, and it’s calculated from the torque and RPM.

While torque gets a vehicle moving and accelerates it, horsepower determines how fast the vehicle can maintain its speed and overcome the forces that try to slow it down, like air resistance.

In summary, torque is important for both initial acceleration and maintaining speed, especially at lower speeds. For increasing vehicle speed, a balance between torque and horsepower is essential. Vehicles with higher torque values often provide better low-end acceleration, which contributes to a smoother and more responsive driving experience.

How to increase the engine torque

To increase engine torque, you’ll typically need to make modifications to the engine or its components. Here are some common ways to achieve this:

Engine Tuning:

Adjusting the engine’s fuel and air mixture, ignition timing, and other parameters through a process known as engine tuning can optimize torque output. This might involve reprogramming the Engine Control Unit (ECU) or using aftermarket tuning modules.

Intake and Exhaust Systems:

Upgrading the intake and exhaust systems can enhance airflow into and out of the engine, improving combustion efficiency and torque output. Aftermarket air intakes, larger diameter exhaust pipes, and performance headers can help achieve this.

Camshaft Upgrade:

Changing the camshaft profile can affect the timing of valve openings and closings, which in turn can impact torque production at different engine speeds. A more aggressive camshaft can provide increased torque at higher RPMs.

Forced Induction:

Adding a supercharger or turbocharger can significantly boost torque output. These devices force more air into the engine, allowing for greater fuel combustion and power generation.

Engine Displacement:

Increasing the engine’s displacement (cylinder bore and stroke) can lead to more torque due to the larger internal volume available for combustion. This might involve an engine swap or a rebuild.

Performance Exhaust Manifold:

Upgrading the exhaust manifold to a performance-oriented one can improve the scavenging effect and reduce exhaust backpressure, which can help increase torque.

Performance Headers:

Replacing the stock exhaust headers with performance headers can improve exhaust flow, contributing to better torque output.

High-Performance Air Filters:

Upgrading to high-flow air filters can improve air intake efficiency and lead to a small increase in torque.

Higher Octane Fuel:

Using a higher octane fuel can allow for more aggressive timing and better combustion, potentially resulting in increased torque.

Engine Balancing and Blueprinting:

Balancing the engine’s internal components and blueprinting (precisely matching and machining) critical engine parts can reduce friction and vibration, leading to better torque delivery.

Transmission and Differential Upgrades:

Modifying the transmission or differential ratios can optimize torque delivery to the wheels, improving acceleration.

Final thoughts

Increasing engine torque through modifications, as mentioned earlier, involves enhancing the engine’s ability to produce more of this twisting force. Just like switching to a lower gear on the bicycle allowed modifications to the engine can improve its performance in various driving conditions.

Remember that while increasing torque can enhance performance, it’s important to consider the overall impact on the vehicle’s reliability, emissions, and fuel efficiency. It’s recommended to seek expert advice and carefully plan any modifications to ensure they align with your goals and the vehicle’s intended use.

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