There are plenty of choices out there for clutches, and choosing the right one requires a bit of understanding. After reading this article, you’ll have a better idea of what to look for in a clutch. It’s something you’ve got to live with for a while, so make the right choice upfront. First things first, what are you going to be using your car for? Do you take it to track days often? How much power does it have? How are you going to be driving it? Once you have the answers to these questions, you can then start looking at different types of clutches. The way you drive and the car you’re using has a huge influence on the type of clutch you ought to get.
Puck-style discs have less surface area, which means it can dissipate heat quicker. Because the surface area is smaller, there’s more pressure on the disc, allowing it to heat up to operating temperature faster. This can cause it to wear out quicker and it may be noisier. Puck-style discs are better suited for racing applications. The power your car is making will naturally dictate the number of discs you need. By utilizing more surface material, they can generate a lot more friction and handle more torque. Because the individual discs can then be made thinner, properly engineered multi-plate clutches are lighter and allows for quicker shifting.
However, with more moving parts, multi-plate clutches can be noisy and produce more vibrations. They are also generally trickier to engage, meaning that it’s easier to stall a car with multi-plate clutches. Not the easiest to use in heavy traffic. The pilot bearing provides support to the transmission input shaft. It is typically made of a sintered bronze or brass material, but most modern transmissions require the use of a roller-bearing style pilot bearing. This is due to tighter manufacturing tolerances in modern transmissions.
Roller bearings also produce less drag and provide increased longevity. The flywheel is the energy storage unit for the clutch system. It provides inertia to maintain rotation when the clutch pedal is depressed, and allows for a more even and controlled clutch engagement. Most flywheels are made of billet steel, for longevity and easy clutch engagement.
Aluminum flywheels are used more in drag racing applications where smooth engagement is not of primary concern. The pressure plate is the workhorse of the clutch system. It provides the clamping force necessary to prevent clutch slippage. Pressure plates come in 2 basic styles, diaphragm style in most modern clutch setups and 3-finger. The diaphragm style, exclusively, provides you with easier clutch action, smoother engagement and longer clutch life.
The clutch disc gets the most wear and is the reason for most clutch system issues. There are 2 basic types of clutch disc construction: sprung hub and solid hub. The solid hub is used primarily in high horsepower all-out racing applications, while the sprung hub system is used in practically every other application. The sprung hub design helps to absorb the shock during initial engagement of the clutch, and allows that shock to be dissipated before it can cause damage to the drive train. Performance clutch discs use heavier-weight springs to absorb more of the load caused by higher horsepower engines, and Mitsubishi evo performance clutch can have a polyurethane cover over the spring for increased life and higher spring rates.
Organic material is common to all stock clutch discs, and offers the best drivability but has limitations as operating temperatures rise. Under high loads accompanied by slippage, they fade because their coefficient of friction drops off. Kevlar material offers a higher coefficient of friction than organic material, but with some loss in drivability. As the coefficient of friction goes up in the disc material, so will the aggressiveness of the material on engagement. This means that some chatter can be expected with this material in low gear and reverse. Kevlar is compatible with stock flywheels and pressure plates, making it a good upgrade choice. Sintered iron is well known for its ability to withstand some slippage and not lose its coefficient of friction. It is the material choice for high horsepower clutch applications.
A street version of the sintered iron disc is the RAM 900 series, which utilizes a sprung hub. These discs should be used only with RAM steel or aluminum flywheels or excessive wear to the friction surface will occur. A key feature of the competition sintered iron material is that it is maintainable. If the clutch is slipped excessively, the disc can be resurfaced and reused. There are many type of clutch kits available for different cars like for Toyota there is a Toyota 86 clutch and for Honda there is Honda integra clutch kit.