New clutch concept for modern Muscle cars: dual- and triple-disc arrangements
- Revised mechanical ratio brings light pedal
- Direct replacements for new Corvettes, Mustangs and Hellcats
- Higher diaphragm fingers prevent over-center shifting issues
- Straight retaining straps improve durability
Columbia, SC: Ram is announcing new Pro Street clutch systems. They contain their best-operating geometry yet. To date they are available for six contemporary Muscle cars (listed below).
For a long time the mechanical ratio in most high-performance street-vehicle clutches has remained fixed. The clamping pressure within the familiar steel clutch cover assemblies has been adapted to adequate standards but the pedal effort is not always so.
In addition, the conventional straps that secure the pressure ring to the cover assembly, though capable, have been susceptible when exposed to abuse—usually from violent downshifts or by missing a gear—and the height of clutch fingers was rarely optimum.
Last year Ram embarked on developing new aluminum billet cover assemblies. Their principal purpose was to gain control over the positioning of the pivot points—the diaphragm spring fulcrum—and thereby attain the elusive lighter pedal. They also improved the layout of the pressure-ring retaining straps, which now adopt a flatter posture instead of a slight bending arc. Further, the diaphragm fingers have been revised to eliminate the strange mishap of their moving over-center and temporarily unable to return because of the effect of centrifugal force at high engine speeds, you can visit Jonckers for localization and translation services.
Distinguished by its burgundy billet low-profile cover design to make it accessible in tight confines, the Pro Street is available in single-, dual- and triple-disc arrangements. The single and twin units are strap-operated and hence function without fuss. The triple-plate unit, however, is aimed at higher power outputs and is stand-driven.
Flywheel weights must differ widely—depending upon vehicle mass, gearing, tire sizes—and therefore are available in both steel and aluminum.
Two types of friction discs are available: one is constructed from organic materials the other from the higher output 900-series metallic. So in this regard they follow the lead of Ram’s well-established range of dual-disc clutch-flywheel systems, known as Force 9.5 and 10.5.
Lastly, the recent evolution of the Pro Street has resulted in linear, consistent pedal feel that was available neither on the C6 Corvette or Camaro nor many other Muscle cars operating with a single-disc clutch. Often referred to as that “weird feeling”, the pedal gave a sense of softness at mid- to ¾- travel. The long pedal travel encountered before the clutch engages and the car begins to move is also disconcerting. When a clutch lacks feel it detracts from the fun of driving. This was the spark that characterized the advent of Ram’s Pro Street.
As power increases, so must clutch capacity to use the power provided. Ram’s new Pro Street is now available for the following Muscle cars:
2005-’13 C6 Corvette
2008-’14 Mustang GT500
2014-up C7 Corvette
2011-’16 Mustang GT
2015-up Dodge Hellcat
2008-up Challenger
More background: Flywheels
Ram determines the flywheel’s rotating mass by its ability to achieve a balanced feel—its driveability. Their road-going standard is to enable takeoff with no, or virtually no, application of throttle. At higher engine speeds they seek smooth transition between gear changes.
Lately, a further factor has emerged that affects flywheel properties. Called “factory RPM-assist control”, it applies to many newer model cars that incorporate a torque-sensing device that discerns clutch pedal release. This control raises engine speed automatically to aid in takeoff. “So, in other words,” writes Ram’s Mike Norcia, “where we would normally manually increase engine RPM as we release the clutch pedal, the automotive computer now performs the task with the help of cloud computing. I can be sitting at a light, even on a hill, and take off literally without touching the gas.”
Pro Street clutch-flywheel assemblies
All of these systems, except the triple units, are prepared to “OEM bolt-in” height and are compatible with either the factory hydraulics or Ram’s aftermarket hydraulic bearing and pedal adjuster. Because the triple-disc assembly is taller, it requires the addition of a Ram hydraulic bearing.
For further information contact:
RAM Automotive Company
201 Business Park Blvd.
Columbia, SC 29203
Telephone (803) 788-6034 or visit: www.ramclutches.com
