Twin-disc clutches are designed to have a lower inertia, but have higher torque holding capabilities, as they spread the load out over more surface area. Twin-disc clutches tend to be noisier in comparison to their single disc counterparts, simply because there are more plates and separators in the “package.”

So, a good rule of thumb is that a single disc clutch is a good all-around performance clutch on a stock or mildly modified engine. Depending on the clutch material used, it will have OE-like engagement and shifting qualities. Twin discs are designed to handle a lot more torque than a stock or even aftermarket single disc; therefore they are a better fit in higher horsepower applications. To make the right choice, know the torque capability of your engine, and as easy as it is to do, consult the clutch manufacturer.

Weighted Rotation

Finally, we can’t talk about clutches, and not mention flywheels. It’s simple; the flywheel not only has the teeth for starter engagement, it is an energy-storing device. A heavy flywheel will cause the engine’s rpm to climb at a slower rate than that of a lighter (aluminum) flywheel. But, since it also stores more energy because of its mass than the lighter flywheel does, the engine’s rpm will not drop as dramatically (like between shifts) as it would if using an aluminum flywheel. On the other hand, a lighter flywheel will allow the engine to spin quicker, but a more dramatic drop in rpm will be noticed (like between shifts), and the lighter weight could also cause an issue if daily driving your car. This is because the lower inertial mass of the lighter (aluminum) flywheel means that the car will be harder to get moving from a stop sign or traffic light. Aluminum is generally used in road race/drag race applications where the engine is kept at higher rpm.

Under Pressure

Without a pressure plate, your clutch will not work. The pressure plate applies the clamping force that squeezes the clutch disc between the pressure plate and the flywheel. But, just like with the flywheel and clutch disc, you have a choice to make. For this article, we’ll focus on the three main types of pressure plates: the Long style, the Borg and Beck, and the diaphragm.

The Long-style pressure plate is identified by the three thin fingers that contact the release (throw out) bearing. The Long style plate is usually used in drag race applications, and will have a considerably hard pedal “feel.”

The Borg and Beck style is similar to the Long style, but while it too functions via three fingers, they can be identified by the somewhat wider three fingers that release plate pressure. The Borg and Beck also uses rollers under the pressure plate cover that are forced outward under centrifugal force. This increases the plate load (pressure), with rpm.

Finally, is the diaphragm pressure plate. It uses a series of “fingers” (also called a Belleville spring), that completely encompass the center opening of the pressure plate. The main advantage to this style of flywheel, is that holding the clutch pedal in at a stoplight is much easier than it is with either a Long or Borg and Beck type pressure plate.

So, which flywheel, pressure plate, and clutch material do you think you need now that you’ve smoked your clutch and became a YouTube favorite? The car described at the beginning of this article is a combination that a lot of guys have built, so the popularity of this combination means that a readily-available replacement/upgrade should be available, correct? Well, it is, and Ram Clutches has just what was needed. The high horsepower application that we’re looking at made us take a serious look at a twin-disc unit, and according to the guys at Ram Clutches, “Ram Street Dual-disc systems are specifically engineered for today’s late-model performance cars, and [late-model] engine swaps into earlier vehicles. The purpose of these clutches is to provide smooth drivability [at] high power levels that was previously not available using aggressive friction material-prepped single disc clutches.”

So there you have it, we’ve let you know how to decide what you need, now it’s time for us to see how easy it is—or isn’t, to install.

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