What are Performance Clutches?

First of all, what are clutches?

A clutch refers to the coupling of two rotating shafts.  One shaft is attached to a drive motor, which continues to rotate as long as the motor is engaged.  The other shaft rotates at varying speeds depending on the locking system of the clutch.  By this, it simply means that the other shaft may turn at the same speed as the shaft connect to the drive end, turn at slower speeds, or not turn at all.  In the case of a motor vehicle, the clutch is what is responsible for delivering the power of the motor to the wheels, making them turn and allowing the vehicle to move.

In manual transmission, the vital components of the clutch include a flywheel, (a plate connected to the shaft of the drive motor) and a clutch plate which is connected to the shaft controlling the movement of the wheels.  When the plates are locked, both shafts move with the same speed, and this is when the plates makes full use of the friction between them.  Whenever the clutch pedal is engaged the plates are allowed to part.  It is at this time, when the clutch pads experience wearing, similar to the brake pads of the brake system.

Clutches are made with different materials and design depending on the manufacturer.  Because of this, clutches also vary when it comes to performance.  A clutch is only said to perform well when its plates are still capable of producing friction, and in effect transmitting power to the wheels.  Performance clutches make use of innovative design and materials which exhibit the best gripping capability.  The more friction a clutch is able to produce the more efficient is the delivery of speed.  Friction is delivered more efficiently in varying methods.  First of all, a clutch kit made of lighter materials delivers more power than a heavier one.  This makes sense considering heavier materials consume energy simply to turn so with reduced weight, power loss is also minimized.  Secondly, the clutch kit has to be made of a material, which can handle friction without suffering considerable wear and deformation from the heat.  On this aspect, carbon-carbon is the material of choice.  Not only, is this material resistant to heat produced by friction in the plates, it actually performs, holds, and delivers more power the hotter it gets, plus it never heats up or glazes over.  This material also wears a lot slower than other materials, making it the ideal for drag racing and hard street use.

With regards to design, innovations in the design of the diaphragm spring and pressure plates, the flywheel, and the clutch plates also help ease the stress on the transmission and the engine.  By replacing solid hub disks for example with a puck design which makes use of springs, less stress is experienced by the transmission, and the clutch is engaged more smoothly.  In the same way, by incorporating a dual diaphragm pressure plate instead of the common single diaphragm, a clutch gains the flexibility of handling pressures up to double its normal load.  A common problem within the clutch is that the flywheel is susceptible to deformation because of the heat.  The basic clutch design involves the use of heat shields.  Commonly, these shields are made of solid one-piece rings, which warp due to the uneven exposure of heat.  Because the entire shield is connected, contraction or expansion in one part of the shield affects the portions as well.  An innovative design to address this problem comes in the form of segmented shields.  Because the segments of the shield are not connected, portions exposed to the heat may expand and contract freely, and thus there’s a lesser chance of warping.