Benefits of Adding A Performance Throttle Body to Your Car.

"All that you need to know about throttle bodies, throttle body conversion"

Car geeks and lovers modify their vehicles inside out and we love hearing about people's projects and which mods they have done.

It is high time we covered throttle bodies, and how these affect a car's performance. They prove to be popular with some models and can make a surprising difference to the car's torque and power.

So let's blow open the world of throttle bodies, see what they are, how they work and what effect they have on performance.

Typically the most common modifications are around the exhaust systems and induction kits, neither of which make much difference unless you've done other mods. However, you should also consider the addition of high performing throttle body to your vehicle.

In this article, we’ll cover all that you need to know about throttle bodies, throttle body conversion, benefits, problems, and replacement costs.

What are Throttle Bodies?

They resemble a trumpet, essentially a tube with a taper on the outermost edge, and they are used in automotive engines to improve the air-delivery.

Taking one apart you quickly ascertain that it is an assembly of valves, pins, and sensors embedded into a metal casing.

In normal cars, a throttle body is usually located between the air filter and intake manifold of the engine.

A car will have a throttle body after the air filter and before the intake, but it is possible to have individual throttle bodies for each cylinder of the engine, but getting these perfectly balanced is a challenge, but the reward on offer is greater control over your cars power profile and theoretically a less restricted intake.

When a throttle is fully open the plate inside will generally be angled slightly downwards so will create a restriction in the airflow, so a well designed and shaped throttle body will address this inherent issue and improve your air intake flow.

How Does a Throttle Body Work?

The basic function of a throttle body is to regulate the volume of airflow to the combustion chamber.

It does so by responding to the signals generated by the ECU of your vehicle. When you press the gas paddle in your car, a signal is sent to the airflow sensors attached to the throttle body.

Upon receiving this signal, the throttle body adjusts the opening and timing of its valves so that so it fulfills the requirements of your car.

Generally, the more your press the gas, the larger the opening of the air valve becomes. Allowing more amount of air in the engine.

Velocity of the incoming air is just as important as the volume of air, and a throttle body allows the air to flow more easily into the cylinder.

In the next section, we will that how this timing of valves impacts the performance and output of your engine.

Impact of Intake Trumpets & AF Ratio On Engine Performance

Disclaimer: The following is a little more technical and nerdy, so feel free to skip ahead if you just wanted an overview.

As you might know, the power output of the engine is always a trade-off between RPM and Torque. At high RPM, torque becomes low, and vice versa. Longer and shorter intake trumpets offer engine output in these two different forms. Short trumpets promote higher RPMs, while longer trumpets favor higher torque.

Why is this important and what is its relation with the throttle body we will come back to it in a while. But before we go further, another important concept to understand is the AF ratio or FA ratio.

The air-fuel ratio or fuel-air ratio usually represents the amount of air in fuel or fuel in the air. For a gasoline engine it needs to be around 14.7:1 (the Stochiometric ratio or sometimes referred to as Lambda 1.

On warm up, and to maximize power, or improve fuel economy you need to deviate around this "stochiometric ratio".

If the AF ratio shows a lambda of greater than 1 then the engine is said to run lean and if it is lesser than one then the engine is said to run rich.

To simplify this concept a lean mixture means it has more air and less fuel, and rich mixture means less air and more fuel.

Now coming back, what the throttle body does is that it allows fine tuning and adjustment of everything. It makes these two controls very smart and optimal and by having control over the airflow you can affect the air fuel mix:

  1. The trade-off between torque and RPMs
  2. The AF ratio

In other words, fitting a throttle body allows a faster and more refined control over air, and will affect your air to fuel ratio. This allows you to make more power, or improve fuel economy, and speed up the warmup time.

Are Throttle Body and Carburetors the Same Thing?

Primarily both throttle body and carburetor are components of the fuel injection system of your vehicle. But the function of both parts is different.

A carburetor is responsible for the mixing of air and fuel in required ratios. Upon mixing this air-fuel mixture is delivered via injector to the engine cylinder.

A float reservoir and jet allows the fast flowing, air to mix with fuel essentially sucking up an appropriate dose of fuel to match the incoming air. It was clunky but worked quite well, but fuel injection allows much better control and fine tuning maximising your power/economy throughout the rev range.

On the other hand, the throttle body only regulates the volume of incoming air with respect to ECU commands.

When you press the gas paddle in your car, both the carburetor and throttle body are activated. These components directly impact the power output of your engine.

Benefits of Adding Throttle Bodies

The addition or modification of the throttle body can really make a positive impact on the performance of your engine and car altogether. Some of the most important benefits of adding a throttle body are:

  1. High Power:
    The first and foremost benefit of adding a throttle body is that it increases the power output of your engine. Most people think that the power surge of 5-15 hp is due to more air intake. But actually, it is due to the efficient optimization of air and fuel mixing. If you know what you are doing you can put this peak power exactly where you need it.
  2. Positive Throttle Response:
    A sudden response is experienced when you press the gas pedal. It is because of higher amounts of air rushing in the intake manifold. It makes the car feel a lot more snappy and responsive.
  3. Swift Acceleration:
    High power and positive throttle response is translated into swift acceleration as well. Since the deficiency of airflow that holds your car back is no longer there and you are getting better fuel atomization.
  4. Improved Fuel Economy:
    Smart adjustment of AF ratio can save a lot of fuel. Moreover, when the engine runs leaner, a lesser amount of fuel is consumed and your gas mileage is improved as a result.

Points to Consider Before Adding A Throttle Body

Throttle body is a highly recommended modification due to the above-mentioned benefits. But you should really consider the below points before making the final move.

  1. Engine Type:
    Duly consider your engine type. Some engines such as direct injection or diesel engines don’t use throttle bodies so they are not suitable for all engines.
  2. Device Compatibility:
    Check the compatibility between the throttle body and engine of your cars. Some older cars do not support a throttle body. Hence, you end up losing more instead of gaining.
  3. Your Requirements:
    Get your goals clear. List down the power, acceleration, and torque requirements of your car. It will help you choose the right throttle body.
  4. Engine Housing Capacity:
    If you are looking to upgrade the size of your throttle body then do analyze that how big is big enough. Is your engine block space sufficient to house a larger throttle body? Clearance in your engine bay is also a consideration and we've seen people having to cut large vents to allow the throttle bodies to protrude.
  5. Other Flow Restrictions:
    Consider the engines ability to flow air and exhaust, if either of these becomes restricted you will not maximize your power gains. Generally speaking, if you've improved the air intake you will need to expel more gases through the exhaust so if the exhaust system is not big enough your engine power will not improve.

Common Problems with Throttle Bodies

There are some downsides and problems associated with the fitting of throttle bodies. Some of the problems and drawbacks of throttle bodies are:

  1. Wear out or Complete Failure:
    Like other mechanical components, the throttle body is prone to wear out and ultimately fail you get what you pay for, with cheaper units failing after shorter periods of time. So by adding a new component you are essentially increasing the amount of maintenance you need to do.
  2. Manifold Absolute Pressure Sensor Problems:
    Manifold Absolute Pressure or MAP sensor problems are very commonly associated with throttle bodies. This sensor generates the signal for air and fuel delivery. If it fails or is malfunctioning it will directly impact the functioning of the throttle body, reset the ECU after cleaning the MAP sensor or replacing it or you might get some error codes and lumpy running whilst it tries to work out what is going on.
  3. Carbon Deposits:
    Debris and dust particles can come into the throttle body due to dirty air in general or a clogged air filter. These dirt particles are deposited around the valves. This compromises the working of the throttle body valve. Its only remedy is proper and timely cleaning. We strongly recommend you use a decent air filter, with many performance filters offering shocking filtration.
  4. Throttle Position Sensors Malfunction:
    This sensor directly decides the opening and time of opening of the valve in the throttle body. If it isn’t functioning properly then the throttle body can’t function as well. Sometimes it needs to be reprogrammed and in other cases, it needs replacing.

Are Throttle Bodies suitable for All Engines?

Where gasoline engines can benefit a lot by utilizing a well-designed throttle body, a diesel engine seldom uses it.

The main reason for the absence of a throttle body in diesel engines is their inherent tendency to run lean. In a diesel engine, the ratio of the air-fuel mixture is already decided and there is no need for a throttle body to regulate the volume of incoming air. Instead one regulates the supply of fuel to the engine and this adjusts power and output.

In some diesels notably those with an EGR Exhaust Gas Recirculation you will often still see a throttle body used. This creates a pressure differential in the intake allowing the exhaust gases to flow better.

Diesel engines are made to run lean due to their high compression ratios. The higher compression ratios of these engines allow for diesel fuel to self-ignite so maintaining a Stoichimetric mix is not as important, but you want to avoid making lots of black smoke and soot, typically caused by overfuelling.

Lean mixtures not only increase the efficiency of a diesel engine but also makes the engine run hotter. This eliminates the requirement for a spark plug and paves the way for the self-ignition of fuel.

Most diesel engines are direct injection engines as well. In these engines, fuel is directly injected into the cylinder. The pressing of the gas paddle only controls the opening and closing of these fuel injectors. A throttle body can further complicate the fuel delivery system.

So, it is not a great idea to include a high-performing throttle body in your direct injection engine if it has not been designed to utilize one. That's not to say it's impossible but there are a lot of engineering issues that will need addressing.

Cost of Upgrading/Replacing the Throttle Body

The complete replacement of a throttle body can cost you somewhere between $500 and $750. Although this cost is dependent upon the make and model of your car.

In addition to this, the country of replacement can also impact the cost. As spare parts and labor in some countries are cheaper than in others.

Similarly, uprating and improving your OEM throttle bodies can cost you between $250 and $550. Different combinations of valves and sizes of throttle bodies can affect the power output of your engine, so ask around and do your research if you are doing this yourself.

Why Replacement/Upgradation of Throttle Body is so Expensive?

Some people often consider the replacement or upgrade of a throttle body an expensive task. Due to the excessive cost, it is often viewed as an unnecessary modification.

The prime reason behind the high cost of the throttle body is its complex construction and intricate design details, but the benefits on most cars speak for themselves making this worthy of consideration.

Another important factor that makes throttle body modification so expensive is the presence of very critical sensors around it.

The sensors present in the vicinity of the throttle body include Idle Air Control (IAC), Manifold Absolute Pressure (MAP), Mass Air Flow (MAF), and Throttle Position Sensors (TPS).

All these sensors perform extremely important functions relating to air measurement and fuel delivery calculations. Anything that has to do with their commissioning and decommissioning demands a highly skilled mechanic. Thus, the higher cost of throttle body modification.

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