Horse Sense: A clutch rides between the engine and transmission of a manual-transmission-equipped car. When you release (engage) the clutch, it joins the engine and transmission thanks to clamping power. The throwout bearing is what disengages when you press in the pedal.
As Mustang fans, we've bought into today's free-market, capitalistic society by purchasing components we're either comfortable with, that perform best in our opinion, or strictly by price. Most of us don't really buy the thought of exclusively using one manufacturer. We've always been accustomed to mixing and matching components to maximize performance. We take a part from Manu-facturer A and mix it with another from Manufacturer B. We've seen Edelbrock heads with a Holley intake, Strange Engineering axles with Moser gears, a Roush front bumper cover mixed with Saleen side skirts, and so on.
In this article, we're mixing and matching a Centerforce clutch with an RPS flywheel. It's not because Centerforce doesn't know how to make a flywheel or because RPS can't make a clutch; it's simply because we've heard this is the hot setup on the street. We're adding these parts to an '03 Cobra at Justin's Performance Center. The Cobra has already been upgraded with several bolt-ons and boasted more than 500 hp to the wheels, which was too much for the stock clutch to handle.
Justin recommended Centerforce's DFX clutch in a 1011/42-inch diameter. Centerforce bills the DFX line as its competition-proven clutch for high-horsepower combinations, which need increased clutch-holding capacity. You'd think that capacity would mean a stiff clutch pedal, but you couldn't be more wrong. Thanks to Centerforce's patented ball-bearing actuated diaphragm, clutch-pedal effort is comparable to stock's smooth engagement properties. Having driven the car with the new clutch in place, we can vouch for the smooth, light pedal effort. Had we not been present for the installation, we'd have thought the car boasted the stock clutch.
There are some who will say the '03-'04 Cobras feature an 11-inch clutch from the factory, and that is true. Why would we swap in a 1011/42-inch clutch? JPC's theory is that the 1011/42-inch clutch, along with a corresponding 1011/42-inch flywheel, reduces rotational mass. In other words, a smaller-diameter clutch enables the engine to accelerate quicker due to its lighter weight when compared to an 11-inch combination. In turn, the lighter clutch enables the car to accelerate at a faster rate as well.
The RPS Cyn-R-G flywheel utilizes relatively new technology by using segmented wear surfaces, sometimes referred to as pucks. RPS says flywheels with traditional, single heat shields are more prone to warping because of uneven heating of the shield by the clutch. According to RPS, with a traditional flywheel, the clutch rides around the outer edge of the heat shield at a faster rate than the center of the shield. This uneven heating and cooling is said to be the cause of warped flywheels. Since the Cyn-R-G segmented wear surfaces are not connected, RPS says the wear surfaces can expand and contract without warping. Furthermore, its flywheels are typically 10-15 pounds lighter than factory units, which definitely reduces rotational mass.
Sounds good to us. Check out how the parts fell on this Cobra.
The Centerforce DFX clutch and RPS Cyn-R-G flywheel don't have matching labels, but no one will give this combination a worst-dressed award. With a clutch and flywheel install, we're not interested in looking pretty: we want performance. The Centerforce DFX clutch is available for just about every late-model Mustang application, as is the RPS Cyn-R-G flywheel. The cost of the Centerforce DFX combination depends on your Mustang application, but the RPS Cyn-R-G flywheel typically sells for around $500. The DFX is available in different stages as well, from street/strip combinations to full-on race applications.
First things first. Detach the shifter and remove the H-pipe or X-style crossover, whichever is on the car. Our test car featured a Bassani X-style crossover pipe. We are using a lift, but for you flat-backers,you can replace the clutch with the car on jackstands. We know because we've done it. Just make sure to have the car high enough so the transmission can be removed.
The driveshaft must be removed as well. But JPC's Justin Burchamm and Adam Humm (pictured) chose to leave the driveshaft in the transmission and remove the whole thing as a unit. This saves time because the transmission fluid won't have to be drained or refilled once we're done.