The 5 Best 5.3 EcoTec3 Performance Upgrades Guide

Chevrolet first released the 5.3 EcoTec3 V8 engine in 2014. In the near-decade since then, it has stayed as one of their most popular power plants in the SIlverado lineup. Depending on the model and fuel used, it produces 355-380 horsepower and 383-416 lb-ft of torque. Yet, for those looking to get even more out of their L83 or L8B, there are several 5.3 EcoTec3 performance parts that can increase horsepower and torque. Let’s take a look at some of the top 5.3 EcoTec3 performance parts to transform your stock Chevy/GMC into a real competitor.

5.3 EcoTec3 LB8 and L83 Mods Basics

General Motors/Chevrolet has been steadily producing the 5.3 EcoTec3 since the 2014 model year. The EcoTec3 is part of GM’s fifth generation of small-block V8 engines, which replaced the third and fourth generation Vortecs. Also known as the LT or EcoTec3 series, there’s also a 4.3 EcoTec3 V6 and 6.2 EcoTec3 V8. 

The 5.3 EcoTec3 is a 5.3 liter, direct injected, V8 engine. It uses an aluminum engine block and cylinder heads, with rectangular-style intake ports. Internally, the engine is quite stout. GM used a cast iron crankshaft, hypereutectic aluminum pistons, and powdered metal “I-beam” connecting rods. Compression sits at 11.1:1, and the engine is naturally aspirated. 

The 5.3 EcoTec is an overhead valve (OHV) engine with a single in-block camshaft. The valve train uses variable valve timing (VVT) for improved fuel economy and performance. It also uses Active Fuel Management (AFM). AFM is designed to help improve fuel economy and reduce emissions by cutting power to half of the engine’s cylinders in certain lower-load situations. 

Performance-wise, the engine produces 355 horsepower and 383 lb-ft of torque on regular pump gas. The 5.3 EcoTec3 is also flex-fuel capable: E85 bumps power up to 380 horsepower and 416 lb-ft of torque. In addition, the L8B versions of the engine have GM’s eAssist hybrid powertrain. The eAssist adds up to 13 horsepower and 44 lb-ft of torque in mid-load situations. Max towing with the 5.3 is 11,600 pounds and with a 2,200 pound payload. 

The 5.3 EcoTec3 has been on the market since the 2014 model year, so there is quite a robust and large aftermarket for it. It’s fairly easy to add more than 100 horsepower with just a few basic bolt-ons. 

Chevy 5.3 DoD Delete Kits

While it won’t add any horsepower, a very popular modification to make to the EcoTec3 is a DoD delete kit. DoD means “Displacement on Demand,” and refers to the Active Fuel Management (AFM) system the engine uses to boost fuel economy and reduce emissions. 

Many people do not like the feeling of AFM/DoD when driving. It sucks power and can make the truck/SUV feel very sluggish. In addition, the DoD also limits the lift of potential camshaft upgrades. This makes it a necessary modification depending on how big of cam you are going with (see recommendations below). 

While a DoD delete kit is not cheap, it definitely makes the car drive better on a daily basis and can be needed to help with cam upgrades. One of the most popular kits is the Livernois Motorsports DoD Delete Kit. The LM kit has everything needed to delete AFM on the EcoTec3 V8 except tuning (which LM also offers). Importantly, tuning will be necessary for the engine to function properly after the delete. 

5 Best Chevy 5.3 EcoTec3 Performance Upgrades

Our top 5 Chevy 5.3 EcoTec3 Performance Parts are:

• Cold Air Intake
• Long-Tube Headers
• ECU Tuning & Flex-Fuel
• Camshaft

1) Chevy 5.3 Cold Air Intake Upgrades

The first of our recommended 5.3 EcoTec3 performance parts is a cold air intake. To be fair, the term cold air intake is a bit misleading. Technically, the OEM EcoTec3 intake is a cold air intake itself. Cold air intakes are simply intakes that route the filter away from the engine and towards the fenders. That allows it to grab as cold or air as possible. Colder air has more oxygen which produces more horsepower and torque. Since the OEM intake already does this, an upgraded intake helps through increasing airflow by decreasing restriction and weight. 

By using a larger, lighter, and less restrictive air filter and tubing, your engine will be able to suck in more air at a higher velocity. This is one of the best ways to increase horsepower and torque on the engine, by allowing it to essentially breathe easier. In addition, usually aftermarket intakes are made of heat resistant and lightweight material. This helps shed unwanted weight and keeps temperatures down. They also make the engine bay much more appealing, as they look very sleek. 

Best GM 5.3 Intakes

There are many different intakes available for the Chevy 5.3. We suggest going with the tried and true S&B intakes. S&B are one of the most well known intake manufacturers in the entire truck industry (both gas and turbo-diesels). Their filters are so popular that many other cold air intake kits made by other companies use S&B filters. All of their units come with closed airboxes to reduce temperatures and keep the filter free from debris. 

There are three different S&B intakes for the 5.3 EcoTec3: S&B intake for 2014–2016 5.3 EcoTec3, S&B intake for 2017–2018 5.3 EcoTec3, and the S&B intake for 2019+ EcoTec3. All of these flow 40-50% better than stock, and will add about 5-15 horsepower and torque by themselves. Tuning is not necessary but highly recommended to get the most gains. 

2) 5.3 EcoTec3 Long-Tube Headers

Now that you have upgraded your intake, the next step is to think about opening up the exhaust, too. Just like an intake, a larger and less restrictive exhaust helps the engine breathe better and suck-in more air at a faster rate. Less restriction and less back pressure means more horsepower and torque, and also a considerable amount more volume out of your exhaust, too. 

The most important part of the exhaust to upgrade on a naturally aspirated V8 like the 5.3 EcoTec3 is the exhaust manifold. These are also known as headers. The headers connect directly to the cylinder heads on the 5.3. Their job is to help direct the flow of the exhaust gasses into the cat-back. By upgrading the headers, you’re reducing restriction as close to the engine as possible. That allows the effects to be as substantial as possible and creates the most amount of power. 

There are two primary types of header upgrades: long-tube and short-tube headers. Long-tube headers will offer more performance than short-tube headers, because they replace more of the exhaust manifold. These either remove or replace the catalytic converters with high-flow versions, which is where a lot of the restriction in the exhaust comes from. Long-tubes will usually add 15-25 horsepower and torque. In contrast, short-tubes will be closer to 5-15 horsepower and torque. 

Best Chevy 5.3 Headers

For the best performance, we definitely suggest long-tube headers for the 5.3 EcoTec3 V8. Long-tubes will offer much better performance on the EcoTec3, and are really the best option. There are two long-tube brands we recommend: Kooks and American Racing Headers. 

The Kooks long-tube headers for 2014–2020 5.3 EcoTec3 are made from 304 stainless steel and use 1-3/4″ x 3″ primaries. The other options are the ARH long-tube headers for 2014–20918 5.3 EcoTec3 and the ARH long-tube headers for 2019+ 5.3 EcoTec3. The ARH headed are also 304SS, but have both 1-¾” x 3″ and 1-⅞” x 3” options for primaries. Both the Kooks and ARH headers will offer similar performance as each other. However, the ARH can be had with optional cats, making it more street legal for some states. 

3) Chevy 5.3 EcoTec3 Performance Tuning & Flex-Fuel

Now that you have really opened up the exhaust and intake, your next 5.3 EcoTec3 performance parts should be a flex-fuel sensor and ECU tuning. ECU tuning is one of the most popular mods for any Chevy/GM truck and SUV, and the 5.3 EcoTec3 is no exception. Flash tuning involves using a handheld programmer to install new software onto your car’s engine control unit (ECU). The ECU is what essentially controls the engine. 

Combining ECU tuning with flex-fuel takes the gains to a whole new level. Flex-fuel, or E85 ethanol, is much better for performance than traditional pump gasoline. Full E85 has an octane rating of around ~105, which is substantially higher than your normal 87-91 octane from pump gas. Additionally, ethanol also has superior cooling properties and combusts at a lower temperature vs pump gas. This also helps to reduce detonation and pre-ignition. 

By installing a new tune to your engine, things like the ignition timing, camshaft timing, fuel pressure, and variable valve timing can be optimized to increase the engine’s horsepower and torque output. In addition, if you have other mods — like an upgraded intake or headers — flash tuning will allow you to get even more gains. Usually, with tuning, you can expect to add 5-20% horsepower and torque over stock. 

Best Flash Tuners for Chevy 5.3

For the 5.3 EcoTec3, the top custom tuning option is from Livernois Motorsports. The Livernois Motorsports 2014–2020 5.3 EcoTec3 tuner is one of the most popular tuners for the Chevy 5.3, and they use a proprietary MyCal flash tuning device. They can handle either otherwise stock vehicles or those that have been modified. On a completely stock vehicle with the Livernois Motorsports tune, gains can be up to 29 wheel-horsepower and 34 wheel-torque on pump gas. 

For flex-fuel kits, the 5.3 EcoTec3 DSX Flex-Fuel Kit is a solid option. It is a plug-and-play part that is easily installed into the OEM fuel lines. The DSX kit is not compatible with all tuners, so make sure to confirm it works with your particular tuning solution. With ethanol, you can expect at least 5-10% more in power gains. 

4) Chevy 5.3 EcoTec3 Performance Camshaft Upgrade

For our final 5.3 EcoTec3 performance part, we’re looking at upgrading the camshaft. The EcoTec3 uses a single in-block camshaft, and while it works great stock it’s a great candidate to be upgraded. The purpose of the camshaft is to actuate the engine’s valves opening and closing. Upgrading means getting a camshaft with a longer duration and/or a larger lift. But what does that mean?

A camshaft that has a longer duration will allow the valves to stay open for longer, letting them suck-in more air. Camshafts that have a larger lift will open the valves more, allowing for more air to be ingested into the engine. These contribute a significant amount of airflow and air velocity for the engine, which really increases horsepower and torque. Depending on the size of your cam specs, you can easily add more than 50+ horsepower with the right cam. 

Best Chevy 5.3 Camshaft Upgrades

There are several different camshaft upgrades available for the 5.3 EcoTec3. In addition to tuning, Livernois Motorsports has a plethora of different camshafts available for the 5.3, ranging from moderate to very high-lift and high-duration cams. The more the duration and lift are increased, typically the more unstable the idle and worse low-end power. 

If you are doing a lot of towing, you will want to stick with a lower-lift option that will still keep lots of torque from a stop. For those looking for better numbers and more get up and go, a higher duration and lift cam will be a better option. Keep in mind, not all camshafts are VVT and AFM compatible, so you may have to delete one or both for your particular bumpstick. In order of their aggressiveness, the following are the top 5.3 EcoTec3 camshaft upgrades:

• Livernois Motorsports 5-1B camshaft for 5.3 EcoTec3
• Livernois Motorsports 5-1C camshaft for 5.3 EcoTec3
• Livernois Motorsports Hi-lift camshaft for 5.3 EcoTec3
• Livernois Motorsports 5-2B camshaft for 5.3 EcoTec3

Chevy 5.3 EcoTec3 Performance Parts FAQ