Evolution of Dual Disc Clutch Kits for Street Use

May 31, 2023 | Clutches

For many years, racers have known that optimizing a high horsepower combination requires a capable clutch system and using multiple discs. That’s how such a powerful application can transition smoothly, thus providing for that optimized performance.  

It wasn’t until the late 2000s that the OEM manufacturers figured this out and began introducing dual disc clutches to their street-driven vehicles.

Aftermarket racing clutch companies had known this for years. When Chrysler introduced the 2008 Dodge Challenger with a dual disc clutch kit, it was the first manufacturer to use this technology in passenger cars.  

Ford followed with an aggressive metallic dual disc in the Mustang GT500, but this unit suffered from horrible driveability.  By then, companies like RAM had already produced street dual disc clutch kits for nearly 10 years.

The first street dual disc clutch kits were ‘harsh,’ to put it lightly. 

Our units had a stand-driven floater plate that was loud and rattled when the clutch was disengaged. Other manufacturers used (and still do) two solid center clutch discs, which do not allow driveline shock absorption on initial engagement or while driving under light throttle conditions, causing gear rattle in the transmission. 

Smaller diameters did not help this situation, as the lack of inertia required more slippage on takeoff and accelerated wear.

What did RAM do to design and refine our dual disc clutch kits over the years to the point we are at today?  

We looked at the features of factory and other units on the market and relied on our experience at the race track to try and improve in every area. 

The basis of any good street dual disc clutch kit is making the unit as drivable as possible. Customers today want to have big horsepower and still have the car drive like it came off the showroom floor. This is a big challenge for us as manufacturers.

The first feature is size.  

While building a smaller diameter clutch with aggressive friction materials to hold big power would be easy, this doesn’t make the clutch drive well.  

Using a 10.5-inch diameter system, we can incorporate more clampload with reasonable pedal effort, provide a larger surface area that dissipates heat better, and allow the clutch to maintain its flatness and life over time.  

A smaller diameter clutch may be great for a road race or autocross use, but the inertia provided by a larger unit means less slippage on takeoff to get moving and less wear and tear in the long term.

Clutch disc design is also important. 

While many companies offer disc materials and designs that will ‘hold,’ we always aim to provide a good driving experience.  

Using a sprung hub top disc with a high-capacity spring design, the shock of initial engagement is absorbed by this top disc as the clutch is initially engaged. A design using two solid center discs cannot provide this dampening effect when taking off from a stop.

Finally, fitment comes into play. 

You can have the best dual-disc on the market, but if it isn’t compatible with modern internal hydraulic release mechanisms, it just creates a headache for the installer.  

In most cases, RAM street dual disc clutch kits are designed as a bolt-in, with minimal measuring and compatibility confirmation.  Of course, we always recommend checking these specifications and verifying the setup so that you won’t do the job twice.  

That extra 15 minutes of measuring can save you hours of work down the road.

RAM’s newest dual disc options include the Concept 10.5 dual disc clutch kit, which is designed to be compatible with almost any flat flywheel; it’s essentially our Force 10.5 dual disc clutch kit that doesn’t require the flywheel to be purchased.

The top-of-the-line Pro Street dual disc clutch kit is a complete package with a state-of-the-art billet cover design that mimics many of our high horsepower race units.  

For severe duty use such as Drag and Drive, RAM can provide custom racing dual disc systems that stand up to race abuse and the grind of getting from one track to the next.

We have come a long way from the original RTrack dual disc clutch. It may be time for you to take a closer look at RAM dual-disc clutch kits!