Stock Throttle Body Size (Things You Must Know)

A stock throttle is that butterfly-like valve occupying the space between your car engine’s intake manifold and air intake filter.

The function of a stock throttle body in your car engine is simple, to manage the amount of air and fuel entering the engine.

But this whole activity depends on the driver’s pressure on the gas pedal.

The stock throttle body of different cars come in different sizes and strengths. And these fit into specific engines, which may be modified or unmodified.

Using a throttle body that fits perfectly is essential to your engine’s proper running and functioning.

So, you may be wondering about the size of your engine’s stock throttle body.

For most cars, the stock throttle body sizes fall within 50 mm to 90 mm. Therefore, the size of this device determines how much torque your engine can muster. To measure that stock throttle body size, remove it and count the ports that convert to the throttle body’s diameter.

How Do I Know What Size Throttle Body I Need?

An engine throttle body comes in various sizes, usually measured in millimeters.

So, the depth of the engine’s internal space dictates the Revolutions Per Minute (RPM) that generate the highest horsepower. Larger engines require a higher RPM to create a unit of power.

Therefore, if your engine’s throttle body is more extensive than required, your car will produce a tired feel at low RPM.

But, on the other hand, it will generate excessive power at higher RPM. And at this point, there’ll be a matching air demand from the large bore of the throttle body.

So, a large throttle body for most cars becomes ideal because it enhances performance without beating down acceleration.

However, if your throttle body does not generate enough power at high RPM, you should consider replacing it with one with a higher capacity.

Nonetheless, always go with a throttle body of slightly higher strength than needed.

How Does Throttle Body Size Affect Performance?

A larger throttle body means more air for your engine.

This implies that if you increase the size of the internal partition of the throttle body, more air will be able to enter the engine.

This is a great advantage because the engine works just like a good-sized air pump.

Therefore, pushing up the air levels in the engine dramatically increases the power which the engine sends out.

In some instances, this increase in capacity could hit 15 to 20 horsepower. 

Also, when the engine collects more air, more fuel burns within it, creating more power.

The fuel/air rate sensors in your engine regulate the fuel/air rate. Nonetheless, you may still have to tune the fuel/air ratio in case of a throttle body replacement.

In addition to increased horsepower, a larger-sized throttle body creates a better throttle response.

But still, always pick a throttle body that balances airflow and performance.

How Do You Calculate CFM For Throttle Body?

The cubic feet per minute (CFM) of a throttle body is the amount of fuel and air the delivery component gives an engine using the intake manifold.

When the CFM is increased, the engine’s horsepower goes up. 

Suppose you attach a fuel delivery component that produces excessive CFM, and your engine’s power drops.

However, there is an effective way of calculating the ideal CFM for any machine through a few simple steps:

• Multiply the highest achievable RPM of your engine by the engine’s displacement in cubic inches. For instance, if the engine’s highest possible RPM is 6500 and its size is 350 cubic inches, take the result of 6,500 X 350, which is 2,275,000.
• Divide your result by 3,456. For example, 2,275,000 ÷ 3,456 gives you 658.275.
• Multiply the result by 0.85. This value represents the standard energy volume efficiency. So, 658.275 X 0.85, resulting in 559.

So, you should use a fuel delivery system that can generate 560 CFM on this engine.

Stock Throttle Body Size 5.0 F150

The F150 stock throttle body for engine 5.0 provides more options for your machine.

For instance, it comes with an 80 mm throttle body from the point of manufacture.

Afterward, you can get both 85 mm and 95 mm throttle body components for several models of F150 vehicles.

The 85 mm throttle body is an excellent choice for truck modifications that do not alter the workability.

On the other hand, the 95 mm throttle body feature is even better for trucks with significant changes.

So, if your car has cylinder head work or an additionally forced induction, the 95 mm throttle body is suitable for you.

These throttle body sizes provide reasonable amounts of horsepower, pushing the towing capacity of these vehicles to a high level.

Stock Throttle Body Size 5.7 Hemi

The 5.7 Hemi stock throttle body has a size of 80 mm. Therefore, these throttle body sizes fall from 80 mm to 83 mm.

However, you could still push it to a size of 90 mm, or you could replace it with one having a measurement of 90 mm.

While the 80 mm size fits only for a 5.7 Hemi stock throttle, the 90 mm can also be used on a 6.1 and a 5.4 Hemi.

These modifications come in when you look to increase your engine’s power. 

The larger 90 mm size allows for the entrance of more air into the engine and the resultant production of more horsepower.

However, a few users argue that the upgrade from 80 mm to 90 mm isn’t exactly worth it.

Stock LS1 Throttle Body Size 

The Stock LS1 throttle body has a size of 75 mm. Although it has a similar size to the LS6, their different builds do not allow you to use them interchangeably.

The stock LS1 throttle body has a composite construction and carries a runner length of 11.0 inches.

In addition, this throttle body has a throttle opening of 2.96 inches and a Wilson billet fuel rail.

Also, its 75 Lb Holley injectors create a better fuel efficiency when running the engine.

It attains a peak power of 535 horsepower at a top speed of 6,900 RPM. On the other hand, it reaches a peak torque of 468 Lb-ft at 5,100 RPM.

Significant reviews have lauded the OEM quality and excellent fitment. But, conversely, it is known as the factory intake with the least power.

Stock Throttle Body Size 5.0 Mustang

A 60 mm stock throttle body is excellent for a 5.0 Mustang engine. However, here, advancing to a 70 mm throttle body will not necessarily improve your engine’s power.

This is because your throttle body produces enough CFM for a stock motor.

Experts recommend that you should only upgrade your throttle body size when you begin to modify intake features.

Also, when you boost the performance of your engine, the 70 mm throttle body comes in well.

So, these naturally aspirated 60 mm throttle bodies go well with stock displacement engines such as the 5.0 Mustang.

But for larger models, their 65 mm and 70 mm counterparts do the job quite more excellently. 

Nonetheless, you should always try to understand the extent of modifications you make to your car engines.

This helps to pick out the exact throttle body that functions ideally with your modified engines.

Stock Throttle Body Size 6.4L Hemi

The throttle body size of a 6.4L Hemi is 80 mm. It has an opening taper boring which goes down a widened 82 mm boring.

The tip of its shaft is taken out, and this produces a smooth airflow at the top and bottom and produces an additional 4 mm space for the throttle.

The stock throttle body carries a fresh custom blade welding the accurate factory angles and presets.

A lot of tricks go into the manufacture of this stock throttle body. Consequently, many people go for this throttle body because of its enhanced properties and strength.

Read More: 4.7 to 5.7 Hemi Swap (Things You Must Know).

Stock 5.3 Throttle Body Size 

The Stock 5.3 throttle body has a size of 78 mm. From the factory, this throttle body has a size of 70 mm.

But users have confirmed that this size is bound to drop by at least 1mm after an intense polishing. 

Users have realized that the 5.3 throttle body shares a typical size with the LS1 throttle body.

This is quite advantageous because you can now use them interchangeably due to the similarity in size.

In addition, these budget build throttle bodies provide better options for those looking to make customizations and modifications to their engines.

Stock 4.8 Throttle Body Size

The body size of the stock 4.8 throttle is quite similar to the stock 5.3 throttle body size.

Although several measurements have confirmed that they are not the same, they can fit into engines interchangeably without breaking down. 

However, despite their interchangeability, it is not always advisable to switch them due to differences in their velocity and stock rates.

Furthermore, interchanging these stock throttle bodies does not create a stronger engine; instead, your engine’s power might drop.

So, the size of the stock 4.8 throttle body also measures around 78 mm. But several modifications could cause a decrease in this size. 

Stock LS3 Throttle Body Size

The factory-produced LS3 carries a design compatible with the stock GM-90 throttle body. The opening of this throttle body measures about 94 mm.

Nonetheless, you could use a 92 mm throttle body with the stock LS3.

Previously, the LS3 used a similar 90 mm throttle body to the LS2 and LS7.

But latter designs of this device have come with disparities that now discriminate between these 90 mm throttle bodies and the more compatible 92 mm to 94 mm throttle bodies.

Notwithstanding, these have evolved into more reliable throttle bodies.

Conclusion

Stock throttle bodies come in different sizes. However, these sizes must fit correctly for your engine to burn fuel and create the needed torque.

And although some of these are modified to work in specific ways, they must still fit in to make the necessary power and effect to propel your vehicle.