How Much Horsepower Does the Kenne Bell 3.2L Supercharger Add to Your Ram TRX?

The Ram TRX is already a formidable machine, boasting a supercharged 6.2L Hemi V8 that delivers 702 horsepower from the factory. But for enthusiasts who crave more, the aftermarket offers a clear path to extreme power. Among the most popular upgrades is the Kenne Bell 3.2L supercharger, a twin-screw unit engineered to dramatically increase airflow and boost pressure. This article provides a detailed breakdown of the horsepower gains you can expect from this supercharger, the factors that influence those numbers, and what it takes to unlock the full potential of your TRX.

Understanding the Kenne Bell 3.2L Supercharger

The Kenne Bell 3.2L supercharger is not your typical bolt-on. It uses a twin-screw rotor design, which differs significantly from the factory Eaton TVS (twin-vortex series) supercharger. In a twin-screw setup, two meshing rotors compress air internally before it exits into the intake manifold. This design inherently produces less heat and delivers a more consistent boost curve compared to a roots-style blower. The “3.2L” designation refers to the displacement of the supercharger itself—meaning each revolution moves 3.2 liters of air. When installed on the TRX, this unit can support up to 1,000 horsepower on pump gas and much more with race fuel and larger pulleys.

The Kenne Bell unit also features an integrated air-to-water intercooler system. This is critical for maintaining intake air temperatures under sustained boost. Lower air temperatures mean denser oxygen intake, which directly translates to more power and reduced risk of detonation. The supercharger housing is cast from high-strength aluminum and is designed to directly replace the factory unit without requiring major engine modifications. For a deeper dive into the engineering, visit the official Kenne Bell website.

Quantifying Horsepower Gains

The most common question is simple: “How much horsepower will I gain?” Real-world dyno results from reputable tuning shops and TRX owners show that a Kenne Bell 3.2L supercharger, with proper tuning and supporting modifications, can add between 180 to 250 rear-wheel horsepower over the stock configuration. Because the factory rating of 702 horsepower is measured at the crank, rear-wheel power on a stock TRX typically falls between 540 and 570 hp. With the Kenne Bell 3.2L installed and a conservative tune, rear-wheel numbers often climb into the 720–800 hp range, equating to a crank output of roughly 880–980 hp.

It is important to note that these gains are not just peak numbers. The Kenne Bell supercharger increases the area under the torque curve significantly. Below 3,000 RPM, torque can rise by over 100 lb‑ft compared to stock, making the truck feel much stronger in everyday driving. The Hennessey Performance builds on the TRX often use this very supercharger to achieve 1,000+ hp packages, further validating the potential.

Typical Dyno Results at a Glance

  • Stock TRX (crank): 702 hp / 650 lb‑ft
  • Stock TRX (wheel): ~550 hp / ~600 lb‑ft
  • With Kenne Bell 3.2L + tune (wheel): 720–800 hp / 700–780 lb‑ft
  • With Kenne Bell + full bolt-ons (wheel): 800–900 hp (depending on fuel and pulley)

These numbers are achievable on 93 octane pump gas with a conservative tune. Adding a lower pulley (larger supercharger cog) and race fuel can push the truck well past 1,000 crank horsepower.

Factors Influencing Peak Output

No two builds are identical. Several factors determine exactly how much horsepower your specific TRX will make with the Kenne Bell 3.2L supercharger.

Tuning Quality

This is the single most important variable. The factory ECU on the TRX is complex and requires a custom calibration to safely manage increased boost, fuel, and timing. Professional tuning by a shop experienced with Hellcat-based engines is strongly recommended. A poor tune can result in knock, excessive heat, or lean conditions that damage the engine. Expect to pay for several hours of dyno tuning to dial in the fuel tables, spark advance, and transmission shift behavior.

Supporting Modifications

The supercharger alone will not deliver its full potential without adequate supporting mods. Key upgrades include:

  • Fuel System: The stock fuel injectors and pump may run out of capacity above 800 crank horsepower. Larger injectors (1300cc or more) and a BAP (boost-a-pump) or a full return-style fuel system are often necessary.
  • Exhaust: A less restrictive exhaust (cat-back or full headers) reduces backpressure and helps the engine breathe. Many owners pair the supercharger with 2.5” or 3” piping.
  • Cold Air Intake: Though the supercharger replaces the stock intake path, a larger inlet tube and high-flow filter can reduce restriction upstream.
  • Intercooling: While the Kenne Bell unit has an integrated intercooler, upgrading the heat exchanger and reservoir can further lower intake temperatures.

Fuel Quality

Boost pressure creates heat and increases the risk of detonation. Pump gas (91–93 octane) limits how much ignition timing and boost you can safely run. For maximum power, many owners switch to E85 (if compatible with the fuel system) or a blend. E85’s higher octane rating and cooling effect allow for substantially more timing advance. However, it requires significantly more fuel volume, so a full fuel system upgrade becomes mandatory.

Ambient Conditions

Dyno numbers are influenced by temperature, humidity, and altitude. A hot summer day will produce lower numbers than a cool fall morning due to increased intake air temperature and thinner air. On a DynoJet at sea level and 70°F, expect the highest results. At high altitude (e.g., Denver), power will be measurably less. The intercooler helps mitigate heat soak, but environmental conditions still play a role.

Installation Considerations

Installing a Kenne Bell 3.2L supercharger on a Ram TRX is not a weekend project for the average DIYer, though many skilled mechanics accomplish it in a garage. The process involves:

  1. Draining coolant and removing the factory supercharger and intercooler brick.
  2. Cleaning the intake manifold surface and installing the new gaskets provided with the kit.
  3. Bolting on the Kenne Bell unit, which includes the intercooler core and discharge manifold.
  4. Routing new coolant hoses and wiring for the boost reference map sensor.
  5. Installing the new pulley (usually a 3.5” or smaller diameter to increase boost).
  6. Reinstalling the intake tube, throttle body, and all sensors.

Kenne Bell recommends professional installation to avoid issues such as incorrect belt tension, coolant leaks, or sensor damage. Several reputable shops specializing in Hemi-powered vehicles offer turnkey installation and tuning packages. Expect labor costs to range from $1,500 to $3,000 depending on the shop and location.

Warranty Implications

Installing a supercharger will void your factory powertrain warranty for any claim directly related to the supercharger. However, if you have a good relationship with your dealer, some may still honor unrelated claims. Aftermarket warranties are available but often exclude forced induction modifications. Check your Ram TRX warranty details before proceeding.

Maintenance After Installation

Once the supercharger is in place, routine maintenance becomes more critical. Change the engine oil more frequently (every 3,000–5,000 miles) because higher cylinder pressures and heat accelerate oil breakdown. Check the supercharger drive belt every 5,000 miles for wear. Monitor fuel trims and boost pressure via a scan tool or gauge to catch potential issues early.

Real-World Performance Improvements

Beyond the numbers on a dyno sheet, the Kenne Bell 3.2L transforms the driving character of the TRX. Owners report the following tangible benefits:

  • Acceleration: 0–60 mph times drop from 4.5 seconds (stock) to the mid-3-second range with a good launch. Quarter-mile times improve from the low 12s to high 10s at over 130 mph.
  • Throttle Response: The twin-screw design provides near-instantaneous boost. Even at partial throttle, the truck feels eager and pulls strongly.
  • Off-Road Performance: Low-end torque is vastly improved, allowing the TRX to climb dunes or pull through deep sand with less throttle input. The increased torque also makes towing easier.
  • Everyday Drivability: Despite the extra power, the Kenne Bell supercharger is quiet enough for daily driving. The blower whine is present but not intrusive, and the truck remains civil in traffic when tuned properly.

Many owners on forums like Ram TRX Forum share their before-and-after experiences, often noting that the truck feels like a completely different vehicle—more responsive, louder, and genuinely intimidating.

Cost vs. Value: Is It Worth It?

The Kenne Bell 3.2L supercharger kit typically retails for around $7,000 to $8,500, depending on the included options (pulley size, intercooler upgrades). When paired with professional installation, tuning, and necessary supporting mods (fuel system, exhaust), the total cost can easily exceed $12,000 to $15,000. This is a significant investment, but for those who want the ultimate street and off-road performance from their TRX, it offers excellent value per horsepower gained—often under $100 per extra wheel horsepower. The supercharger also increases the vehicle’s resale value among enthusiasts, though a modified truck can be harder to sell to a mainstream buyer.

Alternatives to the Kenne Bell 3.2L

The TRX aftermarket offers several competing superchargers. The Whipple 4.0L and MagnaFlow/Magnuson 2.65L units are popular choices. The Whipple provides even more top-end potential (1,200+ hp) but costs more and may require more extensive fuel upgrades. The Magnuson unit is less expensive but offers smaller gains than the Kenne Bell. For most owners, the Kenne Bell 3.2L strikes an excellent balance of power, drivability, and cost.

Conclusion

The Kenne Bell 3.2L supercharger can add between 180 and 250 rear-wheel horsepower to a Ram TRX, pushing the truck well into the 900+ crank horsepower range. Real-world gains depend on tuning quality, fuel, supporting modifications, and environmental conditions. When properly installed and calibrated, the supercharger transforms the TRX into a brutal performance machine capable of low-10-second quarter-mile times while remaining usable for daily driving and off-road adventures. For any TRX owner unsatisfied with 702 horsepower, the Kenne Bell 3.2L is a proven, well-engineered solution that delivers meaningful, reliable power.