The LS1 Throttle Body Upgrade Instructions. General Motors/Chevrolet unveiled the 5.7L LS1 V8 engine inside the new C5 Corvette in 1997. The next year, it was also installed in the F-body Pontiac Firebird and Formula, as well as the Chevy Camaro and, briefly, the 2004 Pontiac GTO. It produced 305-350 horsepower and 335-365 lb-ft of torque, depending on the model. While the LS1 is already quite strong out of the box, it is also one of the most popular modding engines. An LS1 throttle body improvement is still quite popular, even though it isn’t one of the Top 7 LS1 mods.
We’ll go over everything you need to know about upgrading your LS1 throttle body in this article. We’ll go through what throttle bodies do and the various throttle configurations available on the LS1. Finally, we’ll discuss proper sizing and our top upgrades recommendations.
Basics of an LS1 Throttle Body
Before we begin, it’s probably best to define a throttle body and its relationship to the engine and performance. The throttle body is a component of the engine’s intake system. It is located between the air intake and the intake manifold and controls the amount of air that passes through. Throttle bodies have what is known as a throttle blade, which opens and shuts to allow air to pass through. The more air that flows through the engine, the more power it can produce.
The standard LS1 throttle body measures 75 mm in diameter. Except for the Corvette, nearly all LS1 engines have a drive-by-cable throttle arrangement (we’ll go over both later). In addition, instead of the 4-bolt configuration employed by later LS series engines, the LS1 uses a 3-bolt arrangement to connect to the intake manifold.
Why Should You Replace Your GM/Chevy 5.7 Throttle Body?
The purpose of installing a wider diameter throttle body is to increase the volume of air that enters an engine. Larger throttle bodies allow more air to enter the intake manifold and, eventually, the engine. More power is produced by increasing airflow and fuelling, and a larger throttle body allows for more air.
The original throttle body is more than suitable for most projects. Upgrade to a larger one is really only necessary if you’re creating a lot of horsepower and the stocker is becoming a hindrance. This is common when expanding the intake manifold to something larger or adding forced induction, such as a supercharger. Most larger intake manifolds necessitate a larger throttle body, which is often in the 92 mm+ range.
Putting a larger throttle body on a build that produces less than 600 horsepower will not result in significant increases. However, if you push it harder in the future, it will prevent a bottleneck from happening. You may notice a change of only 5-8 horsepower, which is unlikely to be significant. Furthermore, using a throttle body that is too large for your power level can cause your engine to lose low-end torque and struggle at low loads. Make sure your throttle body size is appropriate for your construction, not too huge or too little.
What precisely are ported LS1 throttle bodies?
Many individuals choose to transfer their standard throttle body instead of purchasing a larger diameter one. Porting is the process of smoothing and sharpening the inside of a unit to improve air flow and velocity. While it does not increase the diameter, it lets air to pass through faster and with less resistance and turbulence. In many circumstances, a ported throttle body will result in a size increase of 1-3mm.
Spacers for the LS1 throttle body
An LS1 throttle body spacer is another popular choice for LS1 designs. This is a little element that connects the intake manifold to the throttle body. Its purpose is to enhance airflow into the engine. The benefits of these are hotly contested, with some stating they are incredible and others claiming the opposite. It’s probably not worth it for most builds, but it also won’t hurt anything.
GM/Chevy 5.7 Drive-by-Wire Throttle Body Configuration
We previously used the terms “drive-by-wire” and “drive-by-cable,” but what do they mean? Why are many people of the opinion that drive-by-cable is superior? The distinction is in how the throttle blade is activated during operation. If you recall, the throttle blade sits inside the throttle body and regulates the amount of air that passes through. The LS1 in the C5 Corvette is driven by wire, whereas all other LS1 vehicles are driven by cable.
The throttle blade is controlled by a system of sensors that send the accelerator pedal position to the throttle body, instructing it how much to open in a drive-by-wire setup. Drive-by-wire is so named because the signal is transmitted electronically via a system of wires. The throttle blade is operated by a direct connection that connects the throttle body to the accelerator pedal in a drive-by-cable system. The throttle blade opens or shuts in response to the cable’s control, hence the phrase drive-by-cable.
Many people believe that the drive-by-cable design is ideal on older cars since the accelerator pedal responds faster to the throttle body. This makes the car slightly more responsive at first contact, but it has no effect on horsepower/torque. Drive-by-wire was still new for production vehicles at the time, and there were some glitches to work out.
While the drive-by-wire system in the Corvette is sufficient, the drive-by-cable system in Pontiacs and Camaros is thought to be superior. Drive-by-wire configurations are now the norm, but in the late 1990s and early 2000s, LS engines left a lot to be desired.
Sizing of the GM/Chevy 5.7 Throttle Body
As previously stated, the OEM throttle body measures 75mm. This is sufficient for most situations, but there are times when a replacement throttle body is required. When installing a new intake manifold on an LS1, a new throttle body is usually required. Furthermore, you may add a larger throttle body to the factory intake manifold and gain a few horsepower.
Most aftermarket intake manifolds have a throttle body that is larger than the stock 92 mm or 102/3 mm. If you’re going to use an LS1 for an engine swap, you should start with a larger throttle body if you’re going to use a larger intake manifold or want to create more horsepower. That way, you have some leeway without having to worry about a constraint.
Advantages of LS1 Throttle Body Upgrade
The following are the primary advantages of a bigger or ported LS1 throttle body:
- +5 to 15 horsepower
- +5-10 pound-feet of torque
- better air flow and velocity
- Power band that is more consistent
- enhanced throttle response
There are various advantages to replacing the conventional LS1 throttle body. Most notably, depending on the build, you will gain 5-15 horsepower. Larger increases will be seen if the stock throttle body is a hindrance. Builds under 600 horsepower are likely to gain 5 horsepower, but larger builds can gain up to 15 horsepower if the factory LS1 throttle body is a bottleneck.
Improved air flow and air velocity into the engine in cases where the throttle body is a restriction. This allows your engine to breathe more easily and function more efficiently, resulting in a smoother overall power spectrum. Because any limits will be abolished, there will be fewer dips in power. Because of the enhanced flow, you’ll also notice greater throttle response.
Top LS1 Throttle Body Improvements
Here are the top three LS1 Throttle Body upgrades:
- Stock LS1 throttle body ported to 75 mm
- 92 mm LS1 throttle body upgrade
- LS1 throttle body modified to 102/103 mm
We have three suggestions for improving the original LS1 throttle body. To begin, we’ll look at the benefits of porting your factory throttle body, which is a common choice. Following that, we’ll go over the two most common throttle body upgrade sizes, 92 mm and 102/103 mm. We recommend porting the OEM throttle body for naturally aspirated applications using the stock intake manifold. We recommend a bigger throttle body for boosted applications with an aftermarket manifold.
1) Stock LS1 throttle body that has been ported
Our initial recommendation is to use a ported version of the factory 75 mm throttle body. The factory throttle body sizing is more than adequate for the majority of builds, especially those that are still naturally aspirated. You may enhance air flow and velocity while keeping the OEM fitment by porting the stock throttle body.
Porting is a common alternative because it is significantly less expensive than purchasing a new throttle body. Many local machining shops will port throttle bodies for under $100. You can alternatively buy a throttle body that has already been ported, such as the one listed above. On most builds, a ported throttle body will provide around 5 horsepower.
A ported unit is the ideal option for any design that produces less than 600 horsepower. It will most likely fit the stock intake manifold and will not be a bottleneck. Many boosted applications make full use of ported throttle bodies. Going bigger is really only necessary if you’re running a lot of boost and have a larger intake manifold.
2) LS1 throttle body (92 mm)
Price: $349.00 – $409.95
Drive-by-wire throttle body LS Racing 92 mm
The 92 mm throttle body is a good choice if your LS1 build is boosted and you have a new intake manifold. It is a 17 mm enlargement above stock, allowing for significantly improved air flow and velocity. It makes no sense to keep the factory throttle body size if you’re upgrading to a larger intake manifold. You’ll undoubtedly want something larger, and the 92 mm is the smallest of your options.
We have two choices for 92 mm LS1 throttle bodies: Nick Williams and LS Racing. Nick Williams is the industry’s leading LS series throttle body maker, with the best reviews and reputation. They have an amazing drive-by-cable throttle body for the LS1.
LS Racing is not as well-known as Nick Williams, but they still produce high-quality equipment. If you have an LS1-powered C5 Corvette and need a larger drive-by-wire throttle body, LS Racing is your best bet. Because it was designed for the LS2, it has a 4-bolt housing pattern. It will still fit the LS1, but it will require an adapter harness to function.
3) Nick Williams LS1 throttle body, 102/103 mm
Price: $424.95 – $694.99
The Nick Williams 102 and 103 mm throttle bodies are the finest alternative for boosted LS1 setups seeking for the greatest horsepower with the least restriction. These are 27-28 mm longer than stock and 10-11 mm longer than the smaller 92 mm models. As previously stated, Nick Williams is the industry standard for LS series throttle bodies, and their items are flawless.
Nick Williams makes 102 and 103 mm throttle bodies for the LS1, but with a catch. The 102 mm variant is designed for drive-by-cable configurations, which include Pontiacs and Camaros. The 103 mm variant is only for the C5 Corvette’s drive-by-wire configuration. Despite the fact that the drive-by-wire version is slightly larger, they will perform nearly identically. You won’t notice any difference in restriction until you’re actually pushing large horsepower, well over 1,000+ horsepower.
The Nick Williams throttle bodies are designed to work with the Fast LSX intake manifold series, which is one of the best available for the LS1. They will still suit other manifolds, but they were built exclusively for the Fast LSX series and will fit them the best. This contains both Nick Williams’ 92 mm and 102/103 mm variants.
Related : The Guide to LS1 Supercharger Upgrade
Summary of LS1 Throttle Body Upgrades
While changing the LS1 throttle body is not the most frequent mod, it can be very advantageous in the appropriate builds. The stock unit is 75 mm in diameter, which is adequate for naturally aspirated engines and moderate builds. However, if you want to truly crank up the boost, you’ll need something bigger. A ported stock unit, on the other hand, can yield significant gains.
Our recommendations range from porting the stock unit to the largest 103 mm option. As previously said, if your engine is naturally aspirated or produces less than 600 horsepower, stick with porting the factory throttle body. It’s a different situation if you’re running boost and a new intake manifold. The 92 mm alternatives are suitable for low boost projects, but the 102 mm and 103 mm recommendations are suitable for 20+ PSI setups.