ACT Advanced Clutch Technology Explained

When it comes to upgrading your vehicle's performance, few components are as critical as the clutch. It's the unsung hero that connects your engine's power to your wheels, determining how smoothly you shift, how quickly you accelerate, and how much power your drivetrain can truly handle. But with so many options available, how do you choose the right one?

Enter ACT Advanced Clutch Technology. For over 25 years, Advanced Clutch Technology (ACT) has been a leading name in the performance clutch and flywheel market, earning a reputation for reliability, quality, and superior performance. If you've ever felt your vehicle's clutch slipping under hard acceleration or simply desired a more direct and engaging driving experience, understanding ACT's advanced technology could be the solution you've been searching for.

This comprehensive guide will demystify ACT Advanced Clutch Technology, breaking down what makes their products stand out, the key components involved, and how to choose the perfect ACT clutch system to unleash your vehicle's full potential.

What is a Clutch and Why Does it Matter?

Before diving into the specifics of ACT, let's briefly recap the role of a clutch. In a manual transmission vehicle, the clutch is essentially a friction device that temporarily disconnects the engine from the transmission, allowing you to change gears smoothly without grinding. When you press the clutch pedal, the clutch disengages, and when you release it, the clutch engages, transferring power.

A stock clutch is designed for average driving conditions and factory power levels. However, if you've modified your engine for more horsepower and torque, or if you engage in spirited driving, autocross, or racing, your factory clutch can quickly become the weakest link. It might slip under load, leading to a loss of power, excessive heat, and premature wear. This is where a performance clutch, like those offered by ACT, becomes essential.

Introducing ACT: Advanced Clutch Technology

Advanced Clutch Technology (ACT) specializes in engineering high-performance clutches and flywheels that deliver consistent pedal feel, superior torque capacity, and long-lasting durability for both street and race applications. What sets ACT apart is their commitment to in-house design, engineering, and manufacturing, including the production of their own patented diaphragm springs. This vertical integration allows them exceptional control over product quality, performance, and reliability.

ACT's approach to clutch manufacturing is far from one-size-fits-all. They utilize advanced CAD, FEA simulation, and CAM tools to optimize every component, ensuring peak performance and durability. Their products are rigorously tested, often exceeding SFI certification standards, which means they meet stringent safety requirements for racing applications.

Key Components of ACT Advanced Clutch Systems

An ACT clutch kit is typically a complete system designed to work cohesively for optimal performance. While components can be purchased individually, a kit usually includes:

• Pressure Plate: This is the heart of the clutch, responsible for clamping the clutch disc against the flywheel. ACT offers various pressure plate options, each designed for different performance levels and pedal feel:

  • Sport (SP): Offers a 10-30% increase in clamp load over stock with a stock to moderate pedal feel, ideal for mild street use.
  • Heavy Duty (HD): A popular choice, providing a 20-50% increase in clamp load. Expect a moderate increase in pedal effort (15-40%).
  • Xtreme (XT): Designed for higher torque applications, with a 40-120% clamp load increase and a stiffer pedal feel (50-80% increase).
  • Maxx Xtreme (XX): The most aggressive option, offering up to a 100% clamp load increase over factory, suited for dedicated race cars. ACT's proprietary diaphragm spring design is key here, allowing for tremendous clamping force without excessive pedal stiffness.

• Clutch Disc: This is the friction material that engages with the flywheel and pressure plate. ACT offers different materials and designs:

  • Performance Street Disc (SS/Organic): Made from organic materials, these discs offer smooth engagement, quiet operation, and long-lasting performance for daily driving and mild performance upgrades. They are recommended for street use due to smoother engagement and longevity.
  • Race Discs (Cerametallic/Puck): Available in 4-pad (R4, G4) and 6-pad (R6, G6) configurations, these discs use cerametallic friction material for aggressive engagement and superior heat resistance. They are ideal for high-power, track-focused applications and provide faster shifts, though they engage more harshly. The fewer the pucks, the more aggressive and lighter the disc, leading to quicker engine rev-up and rev-down.

• Flywheel (XACT Flywheels): The flywheel provides the friction surface for the clutch disc and helps store rotational energy. ACT offers two main types:

  • Streetlite Flywheels: Considerably lighter than stock, these are optimized for a significant performance boost with minimal drivability compromise, enhancing throttle response and acceleration.
  • Prolite Flywheels: Aggressively tuned for competition use, these are the lightest and strongest ACT flywheels available, rivaling aluminum flywheels in weight but with superior durability. ACT flywheels are typically made from one-piece Chromoly steel forgings for maximum strength.

• Release Bearing, Pilot Bearing, and Alignment Tool: Most ACT clutch kits include these essential components, ensuring a complete and proper installation.

How ACT Technology Enhances Performance

By combining these specialized components, ACT Advanced Clutch Technology delivers several key performance benefits:

• Increased Torque Capacity: This is perhaps the most significant benefit. ACT clutches are engineered to handle substantially more torque than stock clutches, preventing slippage in modified vehicles. Torque holding capacity can increase anywhere from 20% to 400% over OEM.
• Consistent Pedal Feel: ACT designs its pressure plates for a consistent and predictable pedal feel, crucial for precise shifting, especially in performance driving. While pedal effort may increase depending on the pressure plate, the feel remains consistent.
• Enhanced Durability and Longevity: Through rigorous testing, superior materials, and advanced engineering, ACT clutches are built to withstand the demands of high-performance applications, offering longer wear life compared to standard clutches.
• Improved Shifting: The optimized design and precise balance of ACT clutch assemblies contribute to smoother, quicker, and more positive shifts across the entire RPM range.
• Better Throttle Response (with Lightweight Flywheels): Lighter flywheels reduce rotational mass, allowing the engine to rev up and down more quickly, which translates to improved throttle response and faster acceleration.

Choosing the Right ACT Clutch for Your Needs

Selecting the ideal ACT clutch involves matching the system to your vehicle's power output and your driving style. Here's how to approach it:

1. Assess Your Vehicle's Torque Output: ACT recommends choosing a clutch that can handle at least 10% more than your engine's estimated torque output. If you have a modified engine, know your current and projected torque figures.
2. Consider Your Driving Style:
   • Daily Driver / Mildly Modified: An ACT Heavy Duty (HD) pressure plate paired with a Performance Street Disc (SS) is often the best choice. This combination offers increased torque capacity and durability while maintaining a smooth, near-stock pedal feel for comfortable daily driving.
   • Spirited Street / Occasional Track: An Xtreme (XT) pressure plate with a Performance Street Disc (SS) or a 6-pad Sprung Race Disc (G6) provides a significant upgrade in torque capacity and quicker engagement, suitable for more aggressive driving without being overly harsh.
   • Dedicated Race Car / Heavily Modified: For maximum torque capacity and the fastest shifts, consider an Xtreme (XT) or Maxx Xtreme (XX) pressure plate with a 4-pad (R4/G4) or 6-pad (R6/G6) Race Disc. Twin-disc setups are also available for ultra-high torque capacity with surprisingly smooth engagement. Be aware that these setups will have a much stiffer pedal feel and more aggressive engagement.
3. Flywheel Choice:
   • For street applications, a Streetlite flywheel offers a good balance of performance gain and drivability.
   • For competition, a Prolite flywheel provides maximum performance gains by significantly reducing rotational inertia.

Remember, you don't always need the most aggressive clutch available. Choosing an overly aggressive clutch for your power level or driving style can lead to unnecessary discomfort, harsh engagement, and increased wear on other drivetrain components.

Installation and Maintenance Tips

Installing an ACT clutch is a complex procedure that typically requires specialized tools and expertise. It is highly recommended that installation be performed by an experienced, knowledgeable technician.

Key considerations during installation and initial use:

• Cleanliness: Ensure the flywheel and pressure plate friction surfaces are meticulously cleaned with a non-petroleum-based cleaner to prevent chatter and slippage.
• New Components: Always replace pilot and release bearings, and consider replacing the clutch fork if your vehicle is prone to bending them.
• Alignment and Torque: Use the supplied alignment tool to center the clutch disc, and carefully follow the manufacturer's torque specifications and patterns (e.g., star pattern) for pressure plate and flywheel bolts.
• Flywheel Resurfacing: If reusing a flywheel, it must be professionally resurfaced to ensure a smooth, flat surface and correct step height. Inspect for cracks and replace if necessary.
• Break-in Period: This is crucial for optimal performance and longevity.
  • Organic Street Discs: Drive for 300-500 miles with mild engagement, focusing on stop-and-go city driving. Avoid aggressive driving, hard launches, or overheating the clutch during this period.
  • Race Discs: Typically require a shorter break-in of a few hard slips to lap in the surfaces before normal driving or racing.
  • Avoid Overheating: Overheating during break-in can lead to glazing, hot spots, and reduced clutch performance.

Conclusion

ACT Advanced Clutch Technology offers a robust and meticulously engineered solution for anyone looking to upgrade their vehicle's drivetrain. From daily drivers seeking enhanced durability to high-horsepower race cars demanding maximum torque capacity, ACT provides a range of components tailored to specific needs. By understanding the different types of pressure plates, clutch discs, and flywheels, and by choosing the right combination for your application, you can unlock a new level of performance, reliability, and driving enjoyment.

Ready to experience the ACT difference? Research the specific ACT clutch kit that aligns with your vehicle's modifications and your driving aspirations. Have you used an ACT clutch before? Share your experiences and tips in the comments below!

Frequently Asked Questions (FAQ)

Q1: Will an ACT clutch make my pedal feel much stiffer?

A1: It depends on the ACT pressure plate series you choose. While ACT pressure plates are designed for high torque, you can expect an increase in pedal effort ranging from 15-40% for Heavy Duty (HD) series and 50-80% for Xtreme (XT) series, compared to stock. However, ACT designs them to maintain a consistent and predictable feel.

Q2: Do ACT clutches require a special break-in period?

A2: Yes, a proper break-in is essential. For organic street discs, ACT recommends 300-500 miles of mild stop-and-go city driving. Race discs typically require only a few hard slips to lap in the surfaces. It's crucial to avoid overheating the clutch during this period to prevent damage.

Q3: Can I use an ACT clutch with my stock flywheel?

A3: ACT clutch systems are generally designed to work with both stock and good quality aftermarket flywheels. However, if the ACT clutch is part of a conversion kit, it must be used with the corresponding ACT flywheel. Always ensure your flywheel is in good condition (no scoring, heat damage, or warpage) or have it professionally resurfaced to the correct specifications.

Q4: What does "SFI Certified" mean for an ACT clutch?

A4: SFI certification means the clutch product has met stringent safety standards set by the SFI Foundation, a non-profit organization that develops and administers product safety standards for the automotive and racing industries. This certification indicates that the clutch has undergone rigorous testing and is deemed safe for competition use. Many ACT clutches and flywheels are SFI certified.