,
Racing multi disc clutches have some drawbacks. Since these are clutches designed strictly for racing, there is little concession for streetablity. These clutches have solid hubs and no marcel spring. The disc friction material choices are usually limited to metallic, ceramic and carbon. Of these materials only carbon has smooth engagement characteristics but the price is quite steep. In my opinion, carbon is the only streetable friction material for these full race clutches. Carbon is also the only material that can be slipped for a smoother drag strip launch as well in these clutches.
 |
| Taken apart you can see the parts of this Exedy carbon carbon clutch, the pressure plate, the pressure ring, the discs and the floater plate in between the discs. You can see the tangs on the pressure ring and the floater plate that engage on the drive tangs of the pressure plate. |
In a racing multi disc clutch the diaphragm springs and lever ratios are designed for quick release and engagement to speed shifting. These attributes mean that your typical racing multidisc clutch has a very light switch like on and off engagement that when combined with a low inertia make smooth street starts nearly impossible. These clutches are also designed purely for function with no regard for quietness as well. When disengaged the floater plates typically bang around against the pressure plates drive lugs making a chinging noise which sounds like something is broken in the tranny for those who are not aware.
With their increased number of parts and machined billet bits multi disc clutches are expensive. Multi disc clutches also have a shorter service life. With many wearing surfaces, the total stack height in the discs drops twice as fast with a twin disc and three times faster with a triple disc with wear. This reduces clamp load on the discs when engaged. This means that a multi disc clutch will need servicing sooner than a typical single disc. The good news is that a multi disc clutch can easily be rebuilt and serviced which offsets much of the disadvantages of shorter service life and cost.
 |
| Exedy makes multi disc clutches that are streetable. This one features sprung hubs and a sprung floater plate that helps make the clutch quieter. |
