Hellcat Heat Exchanger Upgrades for Max Power Gains

Introduction to Hellcat Heat Exchangers

The Dodge Challenger SRT Hellcat is an incredibly powerful muscle car producing over 700 horsepower from its supercharged 6.2L HEMI V8 engine. This massive power output requires robust cooling systems to maintain safe operating temperatures and allow the engine to produce maximum power repetitively.

One component that is crucial for cooling the forced induction Hellcat engine is the heat exchanger. The heat exchanger plays a key role in getting heat out of the charged air after it leaves the supercharger. This allows the intake air to be cooler before entering the engine, increasing power potential and engine longevity.

What is a Heat Exchanger?

A heat exchanger is a device designed to efficiently transfer heat between two or more fluids. In the context of the Hellcat, the heat exchanger transfers heat from the compressed air charge to the engine coolant.

It consists of a core made of thin metal sheets stacked together to maximize surface area. The intake air passes through tiny channels or fins within the core. Engine coolant flows around the exterior of the core absorbing the heat from the intake air.

This cooled intake charge allows more air to enter the cylinders leading to greater combustion efficiency. The heat absorbed by the coolant is released to the atmosphere through the radiator and cooling system.

Stock Hellcat Heat Exchanger

The stock 2015+ Dodge Challenger SRT Hellcat is equipped with a very capable heat exchanger from the factory. It features a dual-pass design, allowing the intake air to make two trips through the heat exchanger core.

This maximizes heat transfer efficiency in a compact package. The heat exchanger has cast end tanks for durability and resistance to boost pressure fatigue.

The capacity of the stock unit is sufficient for users running moderate power levels. However, for those aiming for 700+ whp or live in hot climates, an upgraded heat exchanger is recommended.

Benefits of Upgrading the Heat Exchanger

Installing an upgraded aftermarket heat exchanger in a Hellcat can provide several important benefits:

Increased Heat Transfer

Aftermarket heat exchangers feature larger cores, more fins, and greater surface areas compared to stock. This allows them to dissipate much more heat out of the charged air for a given size.

The greater heat transfer capacity keeps intake temperatures lower at high power levels. This maximizes power potential on modified engines.

Improved Reliability

Upgraded heat exchangers keep temperatures under control even during hard use in hot weather. This reduces stress on intercooler components and the supercharger. Keeping heat soak at bay improves durability.

Consistent Performance

High intake temperatures cause power loss as they reduce air density. An improved heat exchanger maintains cooler and denser air charge temperatures despite outside air temps or extended high-RPM use.

This allows much more consistent power delivery and performance in back-to-back runs compared to the stock unit.

Supports More Power

Larger supercharger pulleys, boost controllers, or max effort builds require an upgraded intercooler to realize their full power potential. Better heat transfer unlocks more usable power from the modifications.

Types of Upgraded Heat Exchangers

The aftermarket offers many stepped up heat exchanger options for the Challenger Hellcat from several manufacturers. Here are some of the most common upgrade types:

Drop-In Replacements

Drop-in heat exchangers are designed to directly replace the factory unit with no modifications required. They typically offer capacity increases of 15-25% for bolt-on convenience.

Front Mount Intercoolers

Front mount or remote mount intercoolers relocate the heat exchanger to the front of the car behind the bumper. This exposes it to greater airflow allowing large cores for big heat transfer gains.

Air-to-Water Intercoolers

These systems use water cooling rather than air for the heat exchanger. A separate heat exchanger and water pump sheds heat into the water, which is then cooled through a high capacity radiator.

Ice Tank Intercoolers

Ice tank systems circulate the intake air charge through a tank containing ice water. The phase change from ice to water absorbs huge amounts of heat for very high cooling capacity.

Important Heat Exchanger Design Features

Heat exchangers vary widely in terms of design, construction, and quality. Here are some key features to look for when choosing a unit:

Core Size and Fins Per Inch

More surface area sheds more heat. Look for upgrades with larger cores and higher fin counts than stock. More fins packed tighter together improve air turbulence and thermal transfer.

End Tank Design

End tanks need to withstand boost pressure fatigue over time. Look for upgrades using thick cast aluminum or high strength composites.

Airflow Optimization

Smooth flowing inlet and outlet ducts prevent airflow restrictions. Streamlined end tank profiles guide air through the core efficiently.

Dual Pass or Multi Pass

Multi pass designs force the air through the core several times for greater heat transfer. This comes at the expense of greater restriction which can hurt power.

Core Materials and Construction

Cores made from brazed aluminum or bar-plate offer greater durability and efficiency than cheap epoxy or clamshell constructions.

Fitment and Installation

Direct OEM replacements offer easier installs than front mount units requiring bumper removal and custom ducting fabrication.

Installing a Hellcat Heat Exchanger

Proper installation is key to maximizing performance and reliability from an upgraded Hellcat intercooler. Here are some best practices to follow:

Carefully Remove Stock Unit

Take your time removing the factory heat exchanger without damaging any surrounding components. Label hoses and electrical connectors.

Thoroughly Clean System

Use a degreaser to clean the factory charge pipes and fins. Remove all debris before installing the new heat exchanger.

Seal Connections

Use high quality silicone couplers on the intake piping connections with stainless steel T-bolt clamps. This prevents boost leaks.

Manage Condensation

Add drain valves at low points to remove water buildup inside the system. This prevents hydrolock damage.

Secure Mounting Points

Ensure the mounting locations adequately support the weight of the new heat exchanger and do not allow excessive movement or vibration.

Retune Required

An upgraded heat exchanger alone will not increase power. A custom tune optimizing timing and boost is required to realize gains.

Maintaining Your Heat Exchanger

Proper maintenance is required to keep your Hellcat heat exchanger performing at its best. Recommended maintenance tips include:

Periodic Inspections

Visually inspect the fins for damage or debris buildup. Check end tanks and connections for leaks.

Clean Fins

Use compressed air or a degreaser to remove bugs and debris from fin surfaces. Avoid bending the delicate fins.

Replace Seals

Replace aged silicone couplers and clamps to prevent boost leaks causing power loss and premature component failure.

Monitor Coolant Health

Change coolant at recommended intervals to maintain proper heat transfer and prevent corrosion inside the heat exchanger.

Air Filter Replacement

A restricted air filter causes higher intake temps. Follow recommended air filter change intervals.

Conclusion

Installing an upgraded aftermarket heat exchanger is one of the best power adding modifications for the Dodge Challenger Hellcat. Large core units with high fin counts keep intake temperatures under control even at high boost levels.

This allows the supercharged HEMI to produce consistent maximum power run after run. When shopping for a heat exchanger focus on core design, fin density, end tank construction, and fitment for your specific application.

With a quality unit properly installed and tuned, the Hellcat will have no problem unleashing all the power potential of its forced induction powerplant.

FAQs

How much more power will a heat exchanger add to my Hellcat?

A heat exchanger alone will not directly increase power on a stock Hellcat. However, it allows intake air temperatures to be reduced, which allows more timing and boost to be added safely through tuning. This can unlock an additional 30-50+ HP depending on supporting mods.

What size heat exchanger do I need for 900+ HP?

For power levels above 900 HP, you'll want at least a 100 square inch core heat exchanger. Large front mount units in the 200-300 square inch range are recommended for max power builds.

Will an upgraded heat exchanger hurt drivability?

A properly sized heat exchanger won't affect street drivability. Only extremely large cores matched with very low boost levels may potentially cause bogging issues when transitioning off idle.

What brand makes the best Hellcat heat exchangers?

Some top options come from AFCO, JLT, Improved Racing, and Mishimoto. Look for a unit with a rigid high fin count core and cast end tanks to withstand boost pressures.

Can I install a heat exchanger myself?

Direct replacement heat exchangers can typically be installed at home with basic hand tools and a few hours of time. Mounting kits make the job easier. Front mount units require bumper removal and custom ducting.