What Are 5.9 Cummins 12 Valve and 24 Valve Performance Upgrades?

One way to boost the performance of the 5.9L B-series engine is to modify it with aftermarket parts. Even if the 5.9 Cummins 12v and 24v engines are reliable, the earliest ones had less horsepower. A 12-valve 5.9 Cummins has two valves in each cylinder.

A 24-valve or an Interact System B (ISB) 5.9 L engine has six cylinders and four valves per cylinder. If you own a 5.9 Cummins made between 1984 and 2007, your performance upgrade options are many. We will feature the best five 5.9 Cummins 12 Valve and 24 Valve Performance Upgrades. Read on for more information.

The Best 5.9 Cummins 12 Valve and 24 Valve Performance Upgrades?

  • Turbo
  • Exhaust Manifold
  • Air cooler
  • Fuel system
  • Cold air intake

01. Best Upgraded Turbo for 5.9 Cummins:

How does it work and increase performance

One of the best turbo upgrades online is the Blackhorse-Racing HX35W. Ideal for 1999 to 2002 Dodge Ram models, this turbo increases horsepower.

If you own the 2001 Ram 2500 base model with an extended cab and two doors, the HX35 HX35W turbo may not work. If you have a 12v 5.9L engine, call the manufacturer to ask if this may work for you.

Offering an actuator and a T3 standard flange, this turbo model can provide 270 horsepower. Also, it will regulate the pressure and fuel-air load in the combustion chamber. Regarding installation, Blackhorse-Racing recommends using a professional service.

Hence, you should be a passionate car person to install this turbo without reading any instructions. You may be best hiring someone to assist you to do the work well.

Since this turbo upgrade features brilliant craftsmanship and construction materials, it is sturdy and durable. Also, it comes with a manifold and outlet gasket and requires an exhaust pipe diameter of four inches.

Outcome performance benefits

Installing the Blackhorse-Racing turbo in your 24v 5.9L Cummins will trigger performance benefits. As expected, the new turbo will compress air to bring its molecules closer.

Then, it will compel the compressed air to enter the combustion area, where it will facilitate fuel burning. A 12v and 24v 5.9Liter engines already have reliable torque but requires additional power. Adding a turbo will ensure more power and the following benefits:

  • Increased engine efficiency and power– A dependable turbo should increase horsepower to 420 or 470. When the 24valve engine emerged, it offered 235hp and 460lb-ft torque. If you install the BlackHorse-Racing turbo on it, it will provide 270 more horsepower.
  • Durability– A sturdy turbo can produce more horsepower and stay useful for many years. Besides, the cast iron 5.9L engine block can withstand the additional power.
  • Better acceleration – After installing a turbo, your car might accelerate better and reach top speed.
  • Increased overall performance – Installing a turbocharger only will not boost engine performance that much. However, completing a few other performance upgrades will make the turbo more efficient and reliable.

Q/A: How does a turbocharger do its work?

A turbocharger consists of two major sections: compressor and turbine. In the turbine section, there is a wheel and housing that directs exhaust fumes into the wheel.

Then, the turbine wheel draws energy from the hot fumes and begins to spin. Hot gases then exit the housing via the exhaust outlet area.

In the compressor section, there is a wheel and housing and the wheel attaches to the turbine via a forged steel shaft. When the turbine spins, the compressor wheel rotates speedily. High-velocity spinning absorbs and compresses air.

After that, the compressor housing turns the high-velocity, low-pressure air into a high-pressure stream through diffusion. Lastly, compressed air enters the combustion chamber in the engine. Faster burning of fuel leads to more production of power.

Q/A: Why does a 24V 5.9L Cummins turbocharger fail? 

Without a doubt, the 24V engine is more advanced than the 12V 5.9L engine. Regardless, its Holset turbo is among the parts that fail after covering many miles. After it fails, the cold air intake lacks enough pressure to help the engine release adequate power.

A stock 5.9 Holset turbo fails because of damaged oil seals. Worn-out seals will allow oil to drip into the cold air intake and the exhaust.

A cold air intake does not need oil to run as it will clog the intercooler. Oil should not leak into the exhaust because it can damage the oxygen sensors and cause bluish smoke to come out via the tailpipe.

If the bearings in the center hub rotating assembly wear down, the turbocharger also fails. High mileage, poor lubrication, and normal aging can trigger this failure.

Worn bearings can make the compressor fan touch the compressor housing when the turbine is spinning fast. As a result, the metal shavings from friction can fall inside the combustion chamber and ruin the engine.

02. Best 5.9 Cummins Exhaust Manifold Upgrade:

How does it work and increase performance

One way to boost the performance of your 12v or 24v 5.9L engine is to upgrade its exhaust manifold system. In that case, the BD Diesel Performance 1045987 might work for you.

First, we find the BD Diesel Performance more affordable than other options. Then, you need to know the part number of your stock exhaust system. If it is 3967995, 3943875, or 3943871, choose this exhaust manifold model.

Already pre-drilled for pyrometer probe, this exhaust features high-silicon ductile iron material. So, it is likely to last longer. We also like its divided pulse design as it can let this manifold reduce backpressure and allow the turbo to spool up faster.

As it can withstand extreme heat and vibration, the BD Diesel exhaust manifold is robust and reliable. According to users, this product works better than the factory version.

Installation is easy and quick because of the pre-drilled probes, but some users wish the item came with studs and gaskets. Lastly, this item fits Dodge Ram 5.9 Cummins made from 2003 to 2007.

Outcome performance benefits

After installing a new exhaust manifold by BD Diesel Performance, you might notice positive changes. They can include the following:

  • Increased flow – A new manifold will exit gases faster and more efficiently to help the engine stay cool.
  • No more leaks – If your stock cast iron exhausts leak due to cracks, upgrade it. An old exhaust tends to produce a very annoying loud noise. You can stop this noise by getting a new manifold. Besides, an upgrade will boost engine power as it has no leaks and can lower gas temperatures.
  • Better exhaust design – Stock 5.9 Cummins exhaust system consists of cast iron. In particular, the 12valve engine uses a cast iron exhaust that shrinks badly over time due to exposure to varying heat cycles. Getting a new exhaust manifold allows you to choose a more robust, multi-piece design.

Q/A: Do exhaust headers work in the same way as manifolds? 

Exhaust headers were prevalent in the 1960s and 1970s. Today they are rare as most auto manufacturers prefer to fit their cars with exhaust manifolds.

A manifold attach to the engine to receive hot gases directly from the combustion chamber. Additionally, a manifold has different components that let it convert hot gases into less toxic waste before it enters the atmosphere.

Although a manifold and a header appear due to the connected pipes, they do not work similarly. First, exhaust headers are long, snaking stainless steel pipes that do not rust or crack due to high heat.

They do not create backpressure because they deliver fresh air to the combustion chamber.

In contrast, manifolds have a compact size and thick walls that reduce the space through which the hot fumes pass. So, they create backpressure and reduce torque and power.

Q/A: What should I know about the cast iron exhaust manifold?

Many stock exhaust manifolds use cast iron as the construction material. Cast iron can resist high temperatures and pressure from hot engine gases but has higher odds of cracking. Besides being affordable, it is easy to install and maintain.

Manufacturers reduce the cracking problem by thickening the manifold walls. Cast iron manifolds often trigger backpressure that affects engine performance. As a result, you need to substitute your stock iron manifold for stainless steel or an aluminized steel multi-piece manifold.

03. Best 5.9 Cummins Oil Cooler Upgrade:

How does it work and increase performance

An engine will release optimum power and become more efficient if it receives cooler air. Cooler air tends to be denser than hotter air that enters the engine when the turbo is working.

Air becomes hot due to compression. As hotter air has fewer oxygen molecules, it can reduce the engine’s power and torque. Auto manufacturers place an air cooler (intercooler) between the engine and turbo to prevent this problem.

Before the hot air from the turbo reaches the engine, the intercooler cools it. If you change the turbo, get a new intercooler as well.

One of the best intercoolers you can find online is the Ucreative U-SBK-DR9402 model. Ucreative gives you a black and lovely intercooler boot kit with four pieces of silicone hose and eight pieces of T-bolt clamps.

Not everyone who owns a 5.9L Cummin model will benefit from this air cooler. However, it will work for 12v and 24v 5.9 Cummins Dodge Ram engines made from 1994 to 2002.

Heat is bad for your engine, and the Ucreative air cooler promises to prevent it. With its five layers of silicon, this air cooler is resistant to heat, pressure, oil, and fuel.

Hence, it can function well and last longer. Many users found this item more reliable than their rubber factory intercoolers.

Outcome performance benefits

Fitting a high-quality Ucreative air cooler can assure these performance benefits:

  • Frees power – Unlike a turbo, an intercooler does not add power but frees it. An intercooler helps the engine draw cooler air with enough oxygen to support combustion.
  • Resists heat soak –All intercoolers suffer from heat soak. But if you get the best intercooler design with a larger size, it will resist heat much longer.

Q/A: What is the best construction material for an intercooler? 

An aluminum intercooler or charge air cooler is the most long-lasting and reliable part. Aluminum removes heat from the turbocharged air stream so perfectly.

However, aluminum cannot work alone to deliver cooler air to the engine. A reliable aluminum intercooler will also have flexible seals on every tube. Aluminum tubes require the seals to expand and contract freely when temperatures change.

Q/A: What kinds of intercoolers exist?

You can select between front-mounted and top-mounted options. Top-mounted air coolers allow the compressed and cooled air to reach the engine faster.

A front-mounted charged air cooler faces the air reaching the engine, unlike the top-mounted one that directly faces the engine bay.

Besides, the front-mounted intercooler is easier to fit but uses a longer intake path from the compressor to the combustion chamber.

04. Best 5.9 Cummins Fuel System Upgrade: 

How does it work and increase performance?

A 5.9 Cummins diesel engine is already powerful and fuel-efficient. However, you can capitalize on this engine by upgrading its fuel lift pump.

If you can select a lift pump with the correct flow rating, it will improve fuel delivery. We highly recommend checking the Airdog A6SABD426 system.

As it is a vehicle-specific auto accessory, you must contact the manufacturer to know if it will fit your 12v or 24v 5.9 Cummins model. But if you drive a Dodge Ram designed in 2005 or after, this accessory should work for you.

A USA-made product, the Airdog Fuel lift pump weighs twenty-seven lbs. Measuring 20.32cm long, 33.02cm wide, and 48.26cm high, this fuel lift pump system fits easily if you pick it for the correct model.

Offering a painted exterior, the Airdog A6SABD426 lift pump can resist rust and last longer. According to past buyers, this product works flawlessly. Installing work is easier if you have a sump pump or adequate fuel hoses.

Outcome Performance Benefits

Upgrading your current fuel pump can improve performance. Here are the performance benefits you can expect:

  • More engine power– An engine needs to burn fuel while it runs. A lift fuel pump will deliver fuel constantly in correct volumes.
  • Better filtration – A fuel lift pump raises the fuel volume to the correct levels and boosts filtration. Clean oil translates to a better working engine
  • Increased engine life – A lift pump can extend the engine’s life as it reduces the injection pump and injector’s stressful work. Also, it does the arduous work of pulling fuel from the fuel tank to the engine to ensure it never starves.

Q/A: How does a lift pump do its work? 

Normally, a fuel life pump delivers low-pressure fuel from the tank to the injection pump. Hence, it supplies eight to fifteen psi of pressure.

Then, the injection pump forces the fuel into the cylinder at fifteen to thirty thousand psi. A lift pump facilitates the delivery of fuel from the tank to the engine to ensure it always has enough quantity.

Q/A: When can I do a fuel lift pump upgrade?

If you think the stock fuel system has less power, get a lift pump at once. A fuel lift pump will help you make effective use of the engine’s injection pump and injectors. Moreover, you can help your engine receive filtrated and pure fuel.

05. Best 5.9 Cummins Cold Air Intake Upgrade:

How does it work and increase performance?

A cold air intake can work together with the turbo to deliver clean gushes of air to the combustion chamber. While we found other options for the 12v and 24v 5.9L engines, we settled for the K&N 57-1532 cold air intake model.

One thing we love about it is that the 10-year warranty. Next, this cold air intake will boost the engine’s horsepower. As a Dyno-tested accessory, the K & N intake can give you fifty percent more airflow.

Unlike other cold air intakes, this one boost throttle response to help the truck accelerate when it climbs hills when towing.

Once installed, the K&N intake improves the engine sound and protects it from various contaminants. Regarding maintenance, it is easier because you do not have to clean the filter before covering 100,000miles. Installation is easy also because this cold air intake is a bolt-on accessory.

You can select it for your Dodge Ram 2500 or Ram 3500 produced from years 2003 to 2007. Acceptable in every state, the K&N comes from one of the most reputable auto accessory brands with over 50 years of experience.

Outcome Performance benefits

  • Increases horsepower – A K&N cold air intake is for increasing engine power and performance.
  • Increases torque – You need more torque and power if you use your truck for work. Luckily, this intake removes airflow obstruction in the engine to unlock power and torque.
  • Better acceleration – Your truck might accelerate better in an uphill spot of the road when towing by increasing throttle response.
  • Exceptional quality – A K&N upgrade triggers no regrets. Due to having decades of expertise, the company produces very high-quality and professionally tested cold air intakes.

Q/A: What may affect a cold air intake’s power gain?

On a 5.9 Cummins, the cold air intake power gains will vary. One thing that may affect these power gains is other performance modifications you already have.

If you add a tune, you might notice more power gains from a cold air intake than if you had none. Also, a turbo works together with a cold air intake to bring more compressed air into the engine.

Q/A: Will an open cold air intake improve air more than a closed one? 

Yes, an open-air intake will ferry twenty percent more air than a closed-air intake. As a filter on the open-air intake is not within a box, air flows with minimal restriction.

Although a closed cold air intake will flow cooler air, the benefit does not matter if you also upgrade the intercooler.

How to Boost Your 5.9 Cummins Performance(video)