How to choose the right clutch for your car or pickup.

When choosing a new clutch kit for your car or truck, there are several things that you should consider. This Guide has been developed to help you go through all the steps necessary to make the correct decision based on your specific vehicle, taking into account the way the vehicle is used now and in the future. Only through the careful consideration of all the relevant factors can you come up with a decision that will give you a clutch kit with the performance and life expectancy to be considered a true value. In addition, this Guide covers only automotive applications such as cars and pickups.

A vehicle can be used in basically four ways:

* For personal use
* For work (commercial) use
* For street performance
* For the race track

Most vehicles are used in various combination's of the above as well. Keeping this in mind; let’s look at the specifics of each type of use.

Personal use

In this case the vehicle is being used as originally designed and is a daily driver. The cost of maintenance and the ease of use are key considerations in this case. No performance modifications are planned for.

Recommendation: In this case, an aftermarket clutch kit with OE parts would be the best value since these kits are usually less expensive than through a dealer. Be sure to ask the seller if they are using OE components in the specific kit you are buying. These kits come with a 12 month, 12,000 mile warranty. All OE clutch parts are tested to one million cycles which is about 100,000 miles. If you are planning on keeping the car for a while, this is definitely the way to go. If you are considering selling the car soon, a cheaper kit made from low-cost foreign parts may be a possible option. However, the most expensive part of a clutch job is the installation, and if the bearing should squeal or fail, or the friction material wear very quickly, then that less expensive clutch kit will end up costing you more money, even in the short run.

Work or Commercial use

Pickup trucks used for work are often used to haul loads beyond the original design intent. These trucks may also have been modified to increase the original horsepower and torque ratings of the engine to meet these demands. If this is the case, then a moderately upgraded clutch kit with long-life friction materials is the way to go. It is important to let your clutch supplier know how much any modifications have increased the horsepower and torque ratings of the engine. Tire and exhaust modifications should be noted as well. Try to be as accurate as possible so that the clutch is properly matched to your truck. Also discuss any other issues like pulling trailers or working off-road.

Recommendation: A Stage 2 or Stage 3 clutch kit with either Kevlar or Carbotic buttons is appropriate for moderately modified vehicles and would retain the OE clutch pedal effort. For trucks that have been extensively modified, a Stage 4 or 5 clutch kit may be required which would also include a pressure plate with higher clamp loads and extreme duty ceramic buttons. Do not assume that the higher the Stage of a clutch, the better it is for your vehicle. Clutches need to be matched to the torque output and specific vehicle use. A Stage 5 clutch in an unmodified truck will give a hard clutch pedal and a very abrupt engagement. In addition, radically increasing the torque capacity of the clutch means that the rest of the drive-train needs to be upgraded as well; otherwise those parts will fail prematurely and possibly cause safety issues.

A note about Dual-Mass Flywheels in trucks: Until recently, most Diesel pickups came equipped with a dual mass flywheel. The function of this flywheel was to provide additional vibration damping due to the high compression diesel engine. In these applications, many of the dual mass flywheels failed prematurely either due to high loads put on the vehicle or poorly tuned engines. All of these applications have solid flywheel conversion kits available to convert them from a dual-mass flywheel to the more traditional solid flywheel configuration. This is a great choice because the flywheel can then be resurfaced in the future and the clutch kit can be upgraded as well. Some additional vibration in the drive-train is to be expected but is not considered harmful.

Street Performance

Recommendations for Street Performance vehicles follow the same general guidelines as the work truck above with the exception of pulling heavy loads. Cars can have their chips modified, engines worked on, nitrous systems added, exhaust systems modified, and flywheels lightened. All of these changes affect the choice of clutch you would need. In lieu of having your car dyno-tested for specific torque output (either at engine or at wheel), it is very important to keep track of each component manufacturer’s information regarding that part’s affect on horsepower and torque. Keep your number as real as possible so that you don’t over-spec the clutch kit.

Recommendation: A moderately modified car, usually with a chip or exhaust mod only usually fit into a Stage 2 clutch kit which allows the car to be a great daily driver but stays with you when you get on it. This could either feature a higher clamp load pressure plate with premium friction, or an OE pressure plate with a Kevlar long-life friction material clutch disc. For more highly modified vehicles, a Stage 3 through 5 is available with increase clamp loads and specially designed clutch discs. Discuss your options carefully with your clutch supplier and know what you are buying and why.

A word about lightweight flywheels: In addition to providing a mating surface for the clutch disc and a mounting point for the pressure plate, a flywheel dissipates heat and dampens the engine pulsations that are transmitted further down the drive-train. Our recommendation is that unless the absolute quickest shifts are of the upmost importance, we feel you are better off with a new stock flywheel for clutch life and drive performance. As you make the flywheel lighter when going from cast iron to steel and then to aluminum, you increase the transmission of engine vibrations throughout your vehicle (you shake in your seat) and more importantly to your drive-train. This increased vibration will increase the wear on the transmission and differential gears.

Caveat emptor (otherwise known as buyer beware): If you are being sold a high performance clutch for less than what a stock OE clutch kit goes for, you will not be happy. OE clutch manufacturers have their tooling paid for by the vehicle manufacturers, they run the longest production runs at the lowest cost using part number specific tooling, acquire raw materials at the lowest cost, and do it all while meeting the OE manufacturer’s durability and performance standards. To think that you will get a higher performing clutch for less money is really wishful thinking. A clutch can look okay while being made from a cheaper grade of steel, uses steel parts that are under-size, or has a lower grade of friction materials. If you search the web, you will see many stories about unsatisfactory experiences with clutches. That person either did not spec the clutch correctly or bought one based only on price. A little time invested at the time of purchase will be well worth it in the end.

Full Racing

At this point you are concerned about one thing. Winning. Money is just the cost of doing business on the track. So you have done your engineering, know your vehicle, and know who the professionals are in the business you can trust. At this level, we see multi-plate clutch packs with smaller diameters for instantaneous response and high-end friction materials, lightened high-strength alloys, and application specific release systems that last a few races at best. Their value is judged solely by their contribution to winning.

We hope you find this guide helpful. If you have more detailed questions, send us an email or give us a call.