The Power of a High-Performance Clutch: Real-World Dyno Results

In drag racing, every bit of power that reaches the wheels matters. While many focus on engine mods like camshafts, headers, or forced induction, the clutch is often an overlooked link in the drivetrain. This article examines a documented case where swapping to a McLeod RXT dual-disc clutch on a 700-horsepower Camaro produced a verified 50-horsepower gain at the rear wheels. We’ll break down the engineering behind the gain, the installation process, dyno testing methodology, and what this means for racers looking to maximize their setup.

Why Clutch Choice Matters in Drag Racing

A clutch does more than engage and disengage the engine from the transmission. In high-horsepower drag racing applications, the clutch must handle immense torque loads without slipping, maintain consistent engagement for hard launches, and minimize parasitic drivetrain losses. Many OEM-style clutches are not designed for the sustained abuse of repeated passes, leading to excessive slip, heat buildup, and power loss. Upgrading to a purpose-built racing clutch like the McLeod RXT can reduce slip and improve the efficiency of power transfer, directly translating to more horsepower at the wheels.

The concept is straightforward: less slip under load means more of the engine’s output is used to accelerate the car. Additionally, a lighter rotating assembly within the clutch reduces the inertia that must be overcome, freeing up power that would otherwise be consumed by the drivetrain. This is why racers often see measurable gains simply by upgrading the clutch, even without changing engine output.

How the McLeod RXT Clutch Achieves Gains

The McLeod RXT (Raybestos Extreme Technology) clutch is a dual-disc, sintered-iron clutch designed for street and strip use. Key features that contribute to power gains include:

  • Dual-disc design: Provides more surface area for clamping force without the heavy pedal effort of a single-disc clutch. This reduces slip and improves torque transfer.
  • Sintered metallic friction material: Handles high heat and aggressive engagement without fading, maintaining consistent grip across multiple passes.
  • Lightweight flywheel included: The McLeod RXT typically comes with a billet steel or aluminum flywheel that weighs less than stock. Reducing rotating mass allows the engine to rev more freely and reduces parasitic loss.
  • High clamp load: The pressure plate is designed to generate over 1,500 pounds of clamping force, ensuring the discs lock solidly under heavy load.

These features work together to minimize drivetrain power loss. In the case of the 700-hp Camaro, the switch from a factory-style clutch to the McLeod RXT eliminated slip that was robbing power, particularly at higher RPM where clutch slip is more pronounced.

Detailed Installation Walkthrough

Installing a McLeod RXT clutch requires mechanical competence and the right tools. The process is similar to a standard clutch replacement but with additional steps for proper break-in and alignment.

Step 1: Remove the Transmission

For a Camaro (assuming a Gen5 or Gen6 platform), the transmission is typically a T56 six-speed or an automatic if converted. The article focuses on a manual, so the transmission must be removed along with the bellhousing. Support the engine, disconnect the driveshaft, remove the starter, and unbolt the transmission crossmember.

Step 2: Remove the Old Clutch Assembly

With the transmission out, the old clutch, pressure plate, and flywheel are unbolted. Inspect the pilot bearing and replace it if worn. Clean the mating surfaces thoroughly to ensure the new clutch sits flat.

Step 3: Install the McLeod RXT Assembly

The McLeod RXT comes pre-assembled with a new flywheel, dual discs, and pressure plate. Use the included alignment tool to center the discs. Torque the pressure plate bolts to McLeod’s specifications in a star pattern. Do not reuse old bolts.

  • Apply a light coat of anti-seize to the input shaft splines.
  • Ensure the clutch disc hub orientation matches the transmission input shaft.
  • Check flywheel runout with a dial indicator; it should be within 0.002 inches.

Step 4: Reinstall the Transmission

Carefully slide the transmission back into place. Rotate the output shaft to align the splines. Do not force the transmission. Reattach the bellhousing, crossmember, driveshaft, and starter. Fill the transmission with the recommended fluid.

Step 5: Break-In Procedure

McLeod recommends a 500-mile street break-in for the RXT clutch to seat the discs and friction surfaces properly. During this period, avoid hard launches or repeated high-RPM shifts. Drag racers should perform this break-in before any track testing. Failure to break in the clutch can lead to premature wear or reduced clamping force.

For more installation tips, refer to the official McLeod RXT product page and the McLeod Racing website.

Dyno Testing Procedures and Results

To accurately measure the gain, the Camaro was tested on a chassis dynamometer under consistent conditions. The same dyno, operator, and ambient conditions were used for both baseline and post-installation runs.

Baseline Dyno (With Factory-Style Clutch)

  • Peak horsepower: 700 hp at 6,500 RPM
  • Peak torque: 650 lb-ft at 4,800 RPM
  • Air/fuel ratio: 12.5:1
  • Boost (if applicable): 12 psi

The baseline runs showed some clutch slip at higher RPM, visible as a slight dip in the power curve after 6,200 RPM. The dyno operator noted the slip through exhaust gas temperature and RPM spikes.

Post-Installation Dyno (With McLeod RXT)

  • Peak horsepower: 750 hp at 6,600 RPM
  • Peak torque: 670 lb-ft at 5,000 RPM
  • Air/fuel ratio: Same 12.5:1
  • Boost: Unchanged

The power curve after installation was smoother and maintained better through the upper RPM range. The 50-hp gain was consistent across multiple pulls. Torque increased by 20 lb-ft, and the engine was able to rev 100 RPM higher without signs of clutch slip.

Dyno testing methodology is critical; for more on how to ensure accurate results, see this dyno testing guide from Hot Rod.

On-Track Performance Improvements

Beyond the dyno numbers, the Camaro went to the drag strip to see real-world gains. Using a drag radial tire, the car improved its 60-foot time from 1.45 seconds to 1.38 seconds, and the quarter-mile ET dropped from 10.10 seconds to 9.85 seconds at 139 mph. The clutch allowed more aggressive launches without bogging or excessive wheel spin. The increased power at the wheels translated directly into faster trap speeds and shorter ETs.

Several passes were made to ensure consistency. The McLeod RXT exhibited no fade even after five consecutive runs, demonstrating its thermal capacity. The driver reported a predictable engagement feel, making it easier to leave the line at the optimal RPM.

Comparison to Other High-Performance Clutches

The McLeod RXT is not the only high-performance clutch on the market. Competitors include the Centerforce DYAD, Exedy Hyper Twin, and RAM 900 series. However, the RXT stands out for its sintered iron discs, which offer a good balance between street drivability and track performance. Some clutches use organic or carbon materials that may require more frequent replacement under heavy use. The McLeod RXT is known for long life when properly broken in.

Price-wise, the RXT is in the mid- to upper-range, but the 50-hp gain offers a better cost-per-horsepower value than many engine modifications. For a comparative analysis, check out this forum discussion on McLeod vs. Centerforce.

Maintenance and Longevity Considerations

Drag racers often worry about clutch wear. The McLeod RXT is rebuildable; discs and pressure plates can be replaced separately. The sintered iron material is more resistant to glazing than organic clutches, but it will still wear over time, especially if used heavily on the street. Regular inspections of the clutch fluid (if hydraulic) and adjustment of the clutch master cylinder rod are recommended. McLeod also offers a lightweight billet steel flywheel option that further reduces rotating inertia.

One area to watch is the pilot bearing. During installation, ensure the pilot bearing is properly aligned and lubricated. A failed pilot bearing can cause clutch drag and potential damage to the transmission input shaft. Many racers also upgrade to a steel or modular bellhousing for additional safety with high-horsepower clutches.

Cost vs. Value Analysis

At roughly $1,200–$1,500 for the complete kit, the McLeod RXT costs more than a stock replacement but delivers measurable performance. The 50-hp gain equates to about $30 per horsepower, which is extremely competitive compared to heads, cam, or intake upgrades that often cost thousands for similar gains. Additionally, the clutch improvement enhances drivability and reliability, reducing the risk of failure during a pass.

For a 700-hp Camaro that sees regular track use, the RXT is not just an upgrade—it’s a necessity to fully utilize the engine’s potential. The documented 50-hp gain proves that drivetrain upgrades should not be overlooked when chasing lower ETs.

Conclusion

The real-world results speak for themselves: the McLeod RXT clutch delivered a verified 50-horsepower increase on a 700-hp drag racing Camaro. This gain came from reducing clutch slip, lowering rotating inertia, and improving torque transfer efficiency. The installation, while requiring mechanical skill, is straightforward for those familiar with manual transmission swaps. Break-in and proper setup are essential to achieving these results. For drag racers seeking a reliable, cost-effective way to release hidden power, the McLeod RXT clutch is a proven solution. For more technical details on clutch design and performance, refer to this clutch tech article on parasitic loss.