VM: What are the latest technology advancements and clutch trends?
Norton: For technology, I’d say carbon/ carbon units. They are exceptional: high torque and low weight, smooth engagement, and [they’re] easy on driveline parts.
[On trends:] First, multi-discs are popular, [thanks to their] good power holding and driveability. Second, most C5/C6 owners would like improved trans shifting. Though stout, the transaxles do not shift like butter. One way to assist is with the clutch, by reducing the Moment Of Inertia of the rotating assembly and the disc itself.
We can accomplish this with our stock-appearing, lightweight aluminum pressure-plate option, which has other benefits as well. We have [also] introduced a 10.5-inch clutch option that has torque capacities similar to the 12-inch units, but with lighter discs for faster shifting. I see those units becoming very popular this season.
Scheid: Although there have been advances in disc materials, I think the greatest advancement has been in clutch design. Even though McLeod introduced the Street Twin back in the 1970s, the newest designs are street friendly—with the strapping of the floater plate to eliminate the rattle—cost effective, easy to install, and they hold the power.
Our new Modular RXT Street Twin makes clutch installation a snap. Our Modular units come fully assembled. The installer simply unbolts the old clutch and bolts the new one to the factory flywheel.
VM: How do most of your customers order clutches these days?
While it’s easy to get wrapped up in your sweet new clutch purchase, don’t forget safety i
Norton: Most of our LS customers order Super Twins and single-disc Stage 2+ and 3+ clutches, with billet steel and aluminum flywheels. The aluminum pressure-plate option is becoming more popular; I see our new 10.5-inch set becoming very popular this year.
Scheid: Street-friendly twins such as the RST and RXT are very hot right now. That being said, not all customers need them. For those customers who have basic bolt-ons, we still sell a lot of our Street Pro and Super Street Pro single-disc units.
VM: What is your recommended clutch for a 450- to 650-rwhp “street” C5/C6?
Norton: In our line, the Stage 3+ raises the bar of a single disc to over 900 foot-pounds, with good driveability. We would recommend both single and dual-disc units at that power level, and let the end user choose based on budget and future plans that may warrant the upgradeability of the Super Twin.
Scheid: For cars up to 500 rwhp, we would recommend our Super Street Pro single-disc. The clutch has a dual-faced disc with organic lining on one side, and Miba lining on the other. A steel flywheel is recommended for street-friendly driving.
VM: What is your recommended clutch for an 800- to 900-rwhp “extreme street/ ’strip” C5/C6?
Norton: [See above.]
Scheid: For cars that make 500-800 rwhp, we recommend our RST Twin Disc. The RST has organic linings for smooth engagement. The added discs give increased holding power without the use of aggressive materials or the need for heavy pedal effort. A steel flywheel will give the needed stored energy for friendlier street driving.
VM: Should C5/C6 owners keep stock hydraulics when buying a new clutch, or upgrade?
Here’s what happens to a C6’s flywheel when it’s pushed too hard. Note the glazed surface.
Norton: The stock hydraulics in the Vette have been refined for better durability over the years. We don’t see any issues with the C5/C6 factory setups now. But it is good to always replace the slave [cylinder] while the bellhousing is out of the car, and keep an eye on the fluid in the master cylinder, especially on higher-mileage cars. If fresh fluid starts to get dirty, the seals may be nearing the end of their lives, and actuation issues may soon arise.
Scheid: The C5/C6 hydraulics are fine, unless the customer decides to go with a pressure plate that requires much more pedal pressure. For example, we offer a Borg & Beck-style twin. The Borg & Beck-style pressure plate is ideal for high-rpm LS applications. It doesn’t get sucked in and cause high-rpm shifting problems like a diaphragm-style can. We recommend changing the master cylinder when using a pressure plate that requires more pedal pressure.