The Throttle Body Guide for LS2. The GM/Chevy 6.0 LS2 V8 engine has been a popular power plant for performance builds since its introduction in 2005. It was used in vehicles such as the early C6 Corvette, Pontiac GT/G8, Trailblazer SS, SSR, and CTS-V. Previously, we looked at the Top 5 LS2 Mods, an LS2 Supercharger Guide, and an LS2 Headers Guide for the 6.0 L engine. Today’s topic is LS2 throttle body upgrades.
While a tb upgrade is not as common as some other mods, it can provide solid power gains and significantly increase airflow into the engine on the right builds. There are numerous kits available, however the vast majority of them are completely useless.
Our guide will help you navigate any throttle body questions or upgrades and cut through the clutter. We’ll go over the greatest throttle bodies on the market and compare them based on price, performance, and craftsmanship. Let’s get this party started.
*Keep in mind that the LS2 was offered in a broad variety of cars. This guide is intended to cover as many LS2 equipped automobiles as feasible. However, before making any purchases, make sure you confirm fitment with your specific vehicle model.
Basics of an LS2 Throttle Body
First, let’s go over what throttle bodies are and what they do. They are located between the intake and the intake manifold and control the amount of air that passes through. To control the flow, there is a blade in the center that opens and shuts depending on how much air is required. The stock throttle body from 2005 to early 2008 came with a silver blade for the throttle body. The blade was changed to gold in mid-2008.
The GM/Chevy 6.0 engine employs a “drive-by-wire” (DBW) configuration, as opposed to a “drive-by-cable” (DBC) configuration, which we’ll discuss later. The stock unit has a diameter of 90 mm, which is quite large in terms of stock sizes. In terms of the LS series of engines, the engine has a unique throttle body. It differs from the LS1 tb in that it has a four-bolt design rather than a three-bolt, and it differs from all LS3+ series engines in that it is DBW rather than DBC.
Why should you upgrade to larger GM/Chevy 6.0 throttle bodies?
The goal of increasing the diameter is to increase the volume of air that enters an engine. A larger diameter allows more air to enter the intake manifold and, eventually, the engine. The only method to boost power is to increase airflow, which throttle bodies are capable of doing.
The stock unit is more than suitable for most designs. 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.
Putting a larger throttle body on a naturally aspirated build with less than 600 horsepower won’t add much in terms of improvements, but it will avoid a bottleneck from forming in the future if you push it harder. You may see an increase of 5-8 horsepower, but it will not 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.
What exactly are ported throttle bodies for GM/Chevy 6.0 engines?
Many people choose to port their stock throttle body instead of purchasing a larger one. Porting is the process of smoothing and shaping the inside of a unit to improve air flow and velocity. While it does not increase the diameter, it allows 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.
GM/Chevy 6.0 Drive-by-Wire Configuration
We mentioned “drive-by-wire” (DBW) and “drive-by-cable” (DBC) before, but what do those phrases signify, and why is DBC deemed superior by many? The distinction is in how the throttle blade is activated during operation.
The throttle blade on a DBW arrangement is controlled by a number of sensors that convey the location of the accelerator pedal to the throttle body, instructing it how much to open. 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 DBC arrangement. The throttle blade opens or shuts in response to the cable’s control, hence the phrase drive-by-cable.
Many people believe that the DBC configuration is superior because 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. The fact that GM/Chevy decided to upgrade to the DBC mid-production should be an indication of its superiority in this application.
Conversion from Drive-by-Wire to Drive-by-Cable for GM/Chevy 6.0
While it is possible to convert the LS2 from DBW to DBC, it is time-consuming and usually not worth the effort. If you have a very high horsepower LS2 build and use it in competition, you should check into it; otherwise, it’s a very expensive process. Alternatively, if you plan to use an LS2 as a swap engine, it may be worthwhile to invest in a DBC system from the start.
A new wiring harness, DBC throttle body, E40 PCM, new accelerator pedal, and an ECU tune are required for the modification. The ECU tune is required so that the engine can function properly when the new DBC is installed. One of the most serious faults is a poor idle, so an ECU tune is required.
LS2 Throttle Body Dimensions
The standard LS2 throttle body diameter is 90 mm, as previously stated. 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 LS2, a new throttle body is usually required owing to forced induction.
Most aftermarket intake manifolds have a throttle body that is larger than the factory 92 mm or 102 mm. Furthermore, you can add a larger throttle body to the stock intake manifold and gain some horsepower, albeit only marginally. If you’re going to use an LS2 for an engine swap, you should start with a larger throttle body if you plan on acquiring a larger than standard intake manifold or running boost.
GM/Chevy 6.0 Gold versus Silver Blade Options
As previously stated, the LS2 throttle body has two blade options: silver from 2005 to 2008, and gold from mid-2008 on. There isn’t much of a difference in performance between the two. The gold blades, on the other hand, act in the opposite direction as the silver blades.
Unfortunately, this implies that the silver and gold blade units are not interchangeable. If you need to replace a blade, make sure you obtain the right one otherwise your car will struggle to start.
Advantages of LS2 Throttle Body Upgrade
The following are the primary advantages of a bigger or ported LS2 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 LS2 throttle body. Most notably, depending on the build, you will gain 5-15 horsepower. Larger gains will be seen if the stock throttle body is a restriction. Builds under 600 horsepower are likely to gain 5 horsepower, but larger builds can gain up to 15 horsepower if the factory LS2 throttle body is a bottleneck.
Improved air flow and 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 restrictions will be lifted, there will be fewer dips in power. Because of the enhanced flow, you’ll also notice greater throttle response.
Top LS2 Throttle Body Improvements
Here are the top three LS2 Throttle Body upgrades:
- Stock Throttle Body Ported
- 103 mm Nick Williams
- 92 mm/102 mm/108 mm LS Racing
1) Stock LS2 Throttle Bodies that have been ported
Mamo Motorsports: $300.00 – $700.00; Weapon X: $300.00 – $700.00
Automobiles: $499.00
The Mamo Motorsports and Weapon X Motorsports ported stock throttle bodies are our first pick for an upgrade. Both of these are 90 mm stock options that have been porting treated to improve flow. These are direct bolt-on replacements for the LS2 manifold and require no calibration or modification.
Both of these options are silver-blade and will fit LS2 engines from 2005 to early 2008. Mamo Motorsports charges $300 if you provide them your core to port, or $700 if they utilize their own core.
You can also inquire about local porting services from local motorsports businesses. It will most likely be cheaper and faster to have it done locally, plus you may be able to collaborate with that shop on your LS2 build.
A ported unit is the best option for virtually any normally aspirated design producing less than 600-700 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 larger is really only necessary if you’re running a lot of boost.
2) 103mm LS2 Throttle Body by Nick Williams
Price: $694.00
Our second suggestion is for individuals considering upgrading their units for enhanced applications. Nick Williams throttle bodies are noted for their high quality, and their 103 mm DBW type has received rave reviews. The majority of their applications are designed for DBC systems, and this is one of the few DBW possibilities they provide.
The diameter is 103 mm, which is 13 mm larger than the factory size, and it is CNC made from billet aluminum. It makes use of the 6-pin connector found on later model wiring harnesses (gold blade). This throttle body requires tuning and will not fit the stock intake manifold or air intake.
If you want a larger diameter tb to run a lot of boost, the Nick Williams 103 mm is by far the best option. It has received positive feedback and has been installed on numerous forced induction LS builds.
3) LS Racing LS2 Throttle Bodies (92mm, 102mm, and 108mm)
Price: $349.00 – $849.00
LS Racing is our next recommendation. LS Racing has three sizes available, ranging from 92 mm to 102 mm to the ultra-large 108 mm. They are all gold blade configurations and will not work with early silver blade engines. It employs a late-model 6-pin electrical harness.
The LS Racing alternatives are all CNC machined billet and intended for boosted applications. With a spacer, the 92 mm throttle body will fit the factory unit and provide minor increases when utilized on the stock manifold. The 108 mm throttle bodies are designed for high boost and high horsepower builds. The 92 mm option costs less than half as much as the much bigger 108 mm variant.
If you’re looking for a large diameter alternative for a high boost application, LS racing offers it. The 92 mm and 102 mm alternatives are also suitable for non-stock intake manifolds and give significant performance gains. Still, we’d recommend upgrading only if you’re using forced induction.
Related : The Ultimate Engine Guide for the BMW B58
Summary of LS2 Throttle Body Upgrades
While upgrading the LS2 throttle body is not the most common mod, it can be very beneficial in the right builds. The stock unit is 90 mm in diameter, which is adequate for naturally aspirated and mild builds, but if you want to ramp up the boost, you’ll need something larger. A ported stock unit, on the other hand, can yield significant gains.
Our recommendations range from porting the stock unit to huge 108 mm choices. As previously said, if you’re running normally aspirated or less than 600 horsepower, porting is the way to go; if you’re using boost, it’s a different story. The 92 mm choices are recommended for low boost setups, while the 102 and 108 mm options are recommended for 20+ PSI projects.
