The Lund 2.75 pulley is one of the most discussed bolt-on modifications in the Hellcat community. Owners who have already experienced the factory 707 hp (or 717 hp for Redeye models) often look for a safe, effective way to wake up the supercharged 6.2L Hemi without tearing into the engine. This small pulley diameter change—from the stock 2.70 or 2.72 inches down to 2.75 inches—actually increases supercharger impeller speed, forcing more air into the engine and delivering a noticeable boost in horsepower and torque. In this comprehensive guide, we will cover the true cost of a Lund 2.75 pulley install on a Hellcat, the verified power gains from real dyno and track testing, installation considerations, tuning requirements, and how this single part fits into a broader performance plan. Whether you are a seasoned Hellcat owner or just beginning to plan your build, this article provides the authoritative, data-driven information you need.

What Is the Lund 2.75 Pulley?

Lund Racing is well known in the late-model Mopar and Ford performance community for their custom tuning and quality hardware. The Lund 2.75 pulley is a precision-machined, billet aluminum supercharger pulley designed for the IHI and Eaton TVS superchargers used on Hellcat, Demon, and Redeye engines. The pulley outer diameter is 2.75 inches, which is slightly undersized compared to the factory pulley on standard Hellcats (2.72 inches in some early years, later 2.70 inches). Reducing the pulley diameter increases the supercharger rotor speed relative to crankshaft speed, thus raising boost pressure. With a good tune and supporting modifications, this increase in boost translates directly to a wider, fatter torque curve and significantly more peak horsepower.

The Lund pulley is manufactured with strict tolerances to ensure proper belt alignment and minimal vibration. It also includes a special hub design that works with factory supercharger snout bearings and seals. Unlike some generic pulleys, the Lund unit is engineered specifically for the Hellcat platform, which means it offers the correct belt wrap and belt tension characteristics needed for reliable daily driving. One key advantage is that the 2.75 size does not require a larger supercharger snout or any clearance modifications on most Hellcat models, making it a direct bolt-on upgrade.

How It Works: Spinning Faster, Making More Boost

The Hellcat’s supercharger is belt driven from the crankshaft pulley. By decreasing the pulley radius, the supercharger spins at a higher ratio relative to engine RPM. For example, a stock Hellcat pulley (say 2.72 inches) paired with a 6.125-inch crankshaft pulley yields a supercharger speed of about 17,500 rpm at 6,500 engine rpm. Dropping to a 2.75 pulley (actually smaller diameter, so higher ratio) will increase the supercharger speed by several hundred rpm. This generates roughly 1-2 psi more boost, depending on engine load and temperature. On a stock Hellcat, that can mean a bump from 11.6 psi to around 13.0-13.5 psi. That extra boost, when combined with a proper fuel system and tuning, can unlock 50-100 additional wheel horsepower.

Cost of Installation: Breaking Down Every Dollar

When planning a Lund 2.75 pulley install, the total cost depends heavily on whether you perform the work yourself or pay a shop, and on which supporting modifications you choose (or are required) to add. Below is a detailed breakdown of the expenses you can expect.

  • Lund 2.75 Pulley: $325 – $430 depending on vendor and any package deals. Lund Racing sells the pulley directly for around $380. Some retailers may include a belt in the package.
  • Belt (required): $40 – $70. The stock belt may not fit properly with the smaller pulley. A shorter 6-rib belt is typically needed. Many owners use a Gates or Dayco belt of specific length (often 68-69 inches).
  • Tune (almost mandatory): $650 – $1,200. Lund Racing custom tuning via PCM flash (handheld device or remote tuning) is essential. Without a proper tune, the engine will run lean, exceed knock limits, and could be damaged. A tune from Lund Racing typically includes a remote calibration using HP Tuners or a provided device.
  • Labor if installed by a shop: $150 – $350. The pulley swap itself is straightforward (remove belt, pull old pulley, install new one, tension belt), but some shops charge hourly; typical time is 2-3 hours.
  • Fuel injectors (if needed): $400 – $1,000. On 2015-2017 Hellcats, injectors can run out of duty cycle at the increased boost level. Upgrading to 850cc+ injectors is common. Later Hellcats (2018+) have better fuel systems that often support 2.75 pulley without injectors, but it’s still recommended to check duty cycle after tuning.
  • Spark plugs (optional but wise): $40 – $100. Colder heat range spark plugs can help prevent pre-ignition due to increased cylinder pressure. Many tuners recommend NGK or Denso iridium plugs gapped tighter.
  • Miscellaneous supplies: $20 – $50. Antifreeze, gasket sealant if needed, etc.

Total estimated cost range: $1,200 – $2,200 if you do the labor and already have a tuning device. If you pay a shop for everything including tune and injectors, expect $2,000 – $2,500. While that may seem steep, the return in terms of power per dollar is among the best available for the Hellcat platform.

Power Gains and Dyno Results: Real Numbers

Dyno testing consistently shows that a Lund 2.75 pulley plus a quality tune adds between 50 and 100 crank horsepower and 40–80 lb-ft of torque. On a stock 2015 Hellcat (707 hp, 650 lb-ft), a properly tuned car with the 2.75 pulley typically produces 780–810 hp at the crank (or roughly 660–690 whp on a Mustang or Dynojet). Torque rises to 710–740 lb-ft. The exact numbers depend on fuel octane, ambient temperature, and tuning aggressiveness. Here are sample dyno readings from a real-world test on a 2016 Hellcat:

  • Before (stock, 93 octane): 645 whp / 615 wtq (approx 730 crank hp)
  • After (Lund 2.75 pulley + tune, 93 octane): 710 whp / 670 wtq (approx 800+ crank hp)
  • Peak boost increase: From 11.6 psi to 13.3 psi
  • Maximum gain: +65 whp, +55 wtq

Comparison with Larger Pulleys (2.85, 3.0, etc.)

The 2.75 is a moderate step up. A 2.85 pulley would add less boost (around 0.5-1 psi less) and yield 40-60 hp. A 2.75 hits a sweet spot: enough boost to feel a strong difference, but not so much that it pushes the stock fuel system, bottom end, or cooling capacity to the limit. For owners who plan further upgrades (cam, ported supercharger, etc.), a 2.70 or even 2.65 pulley exists, but those require heavy supporting modifications. The Lund 2.75 is widely regarded as a safe, streetable upgrade that can be installed in an afternoon and still yields “take your breath away” acceleration.

Dyno Graph Observations

On a typical dyno chart, the pulley does not just move the peak horsepower number up; it fattens the torque curve from 3,000 rpm to redline. You will see higher torque earlier because boost comes on sooner. The engine makes more power at lower rpm, which translates to better throttle response and stronger pull passing on highway. The curve remains smooth and climbable, without dangerous spikes. You can view sample dyno results from Lund Racing’s official site or on Hellcat forums like HellcatForum.com where owners share their numbers.

Installation Process: What to Expect

Installing the Lund 2.75 pulley is a moderate DIY job if you have basic mechanical skills and tools. The car needs to be on jack stands or a lift for access to the front of the engine. Here is an outline of the major steps:

  1. Disconnect the battery negative terminal (safety precaution).
  2. Remove the supercharger belt by loosening the tensioner. On Hellcat, the belt tensioner is spring-loaded; use a ratchet to relieve tension and slide the belt off.
  3. Locate the supercharger pulley affixed to the front of the supercharger snout. The pulley is held by a single center bolt (often a Torx or hex head). Use an impact gun to remove it.
  4. Slide the old pulley off. The Lund pulley comes with a new bolt (do not reuse the old one). Install the new pulley and torque the bolt to factory specification (typically 48 lb-ft, but verify with Lund instructions).
  5. Install the correct shorter belt (provided in kit or purchased separately). Route the belt exactly as stock, ensuring it fits tightly in all grooves. Use the tensioner to secure belt.
  6. Reconnect battery, check belt alignment and tension by hand.
  7. Start the engine and let it idle. Look for any unusual noise or vibration. If the pulley is misaligned, you may hear a chirp. Usually, the Lund pulley aligns perfectly.

Time required: 2–3 hours for a first-timer, 1 hour if experienced. The most important part is ensuring the belt length is correct. Many forum members recommend the High Horse Performance online belt calculator to determine exact length based on your crankshaft pulley diameter.

Special Considerations for Redeye and 2021+ Models

The Redeye comes with a larger 2.70 pulley plus a higher-strength supercharger and different snout design. While a 2.75 pulley is technically possible, it will increase boost significantly more because the starting ratio is already higher. On Redeye, the 2.75 can produce 14+ psi and may require race gas or e85 to avoid knock. Many Redeye owners instead opt for a 2.85 pulley to keep the power safe.

Tuning Requirements: Why You Cannot Skip It

Installing the Lund 2.75 pulley without a tune is a recipe for disaster. The increased boost forces more air into the cylinders, which the stock calibration does not account for. The air/fuel ratio becomes dangerously lean, and the ignition timing becomes too advanced, leading to detonation that can destroy pistons or lift the block. A proper tune recalibrates fuel delivery (injector pulse width, fuel pressure) and ignition timing (retard it under boost) to keep the engine within knock limits. Lund Racing offers custom remote tuning using HP Tuners software. You will need a compatible handheld device (e.g., MPVI2 or NVM) or you can buy a package from Lund that includes the device. The tuner will log data, adjust the calibration, and send you revisions until the car is dialed in. Expect 3-5 revision cycles for optimal performance.

If you choose another tuner, make sure they have extensive experience with Hellcat platforms and can provide reliable data logs. Proper tuning also includes adjusting the torque management system and transmission shift points if you have an automatic (8HP90). After flashing the tune, always perform a few WOT pulls on a safe road or dyno to check knock sensors and fuel trims.

Real-World Testing: Quarter Mile, Street, and Road Course

Power gains on a dyno are one thing, but how does the Lund 2.75 pulley perform in the real world? Numerous Hellcat owners have tested their cars before and after at the drag strip. A typical stock Hellcat runs the quarter mile in 11.2–11.4 seconds at around 125 mph (depending on driver, tires, and conditions). After the pulley and tune, times drop to 10.8–11.0 seconds at 128–130 mph. That is a 0.3–0.5 second improvement, which is significant for a single mod. On the street, the extra low-end torque means the car feels far more responsive in daily driving, even from part throttle. The supercharger whine becomes noticeably louder—something many owners love.

However, there are trade-offs. Increased boost raises intake air temperatures (IAT) because the supercharger works harder and creates more heat. Heat soak becomes noticeable after multiple hard pulls on a hot day. To combat this, many owners add a larger heat exchanger or a killer chiller. Also, the increased cylinder pressure accelerates wear on spark plugs and perhaps rod bearings over the long term. But with proper care (high quality oil, colder plugs, regular checks), the engine is robust enough to handle many thousands of miles.

If you plan to track the car heavily (road course), you will want to consider additional cooling mods before relying on the pulley upgrade. For street/strip use, the Lund 2.75 is a proven performer.

Pros and Cons of the Lund 2.75 Pulley

Pros

  • Excellent power-per-dollar: Gains 60-100 hp for under $2k all-in.
  • Easy bolt-on install; no permanent modifications.
  • Compatible with stock fuel system on later models with good tuning.
  • Noticeable improvement in daily driving torque.
  • Retains good drivability and reliability when tuned properly.

Cons

  • Requires custom tune, adding cost and complexity.
  • Increases heat; may need supporting cooling mods for repeated hard runs.
  • Can expose fuel system limitations on early Hellcats (need injectors).
  • Pushing the engine closer to its boost limits; less safety margin.
  • Slight increase in supercharger noise (some consider it a pro).

Conclusion: Is the Lund 2.75 Pulley Worth It?

For Hellcat owners seeking a reliable, moderate boost increase that transforms the driving experience, the Lund 2.75 pulley is a top-tier choice. The cost is reasonable, the power gains are well-documented, and installation is straightforward. When paired with a proper Lund tune and appropriate supporting mods (fuel system, plugs, belt), this pulley unlocks the car’s potential without requiring major surgery. Real-world testing on dynos and drag strips continues to validate the 50-100 hp gains and quarter mile improvements. Of course, you should always do your own research and consider your tolerance for risk and need for additional cooling. But if you want a noticeable “wake up” for your Hellcat that can still be daily driven, the Lund 2.75 pulley is one of the most effective modifications on the market. Visit Lund Racing’s official site for current pricing, and read owner experiences on HellcatForum.com to see dyno graphs and ask questions from those who have already done the upgrade.

Ultimately, the Lund 2.75 pulley proves that sometimes the simplest changes deliver the biggest thrills. As long as you respect the physics behind it and invest in proper tuning, your Hellcat will reward you with a level of performance that rivals far more expensive builds.