Over the past few years, Project Y2K has seen a steady flow of performance upgrades that have elevated it from a garden-variety C5 Corvette into the realm of formidable modern sports cars. At the drag strip, Project Y2K was a mid-to-high 13 second car when we made our initial passes with it, but these days it’s capable of dipping into the high 11s. You don’t make those kinds of performance gains without a significant dose of both power and grip.
It’s no secret that hard launches can put a lot of stress on a transmission, and when it comes to manual gearboxes, that’s most often translated into clutch wear. We knew that sooner or later the additional output and mechanical grip was going to send that assembly to the boneyard, and after a recent beating, we started hearing sounds emanating from the gearbox that indicated the current clutch wasn’t long for this world.
Rather than wait for the transmission to leave us stranded on the side of the road, we decided to nip the issue in the bud by procurring a replacement piece from Fidanza Performance. The V1 series clutches are designed to provide OEM-level drivability in street cars while bolstering durability in vehicles making more power than stock.
In this feature we’ll take a closer look at the features of the V1 clutch with some insight from the experts at Fidanza Performance and go through the key points of the clutch installation in Project Y2K.
While factory-installed clutches are typically tuned for every day drivability and can last a long time if you’re gentle with the gearbox, the story changes significantly once you start adding power and really put the car through its paces at the track. Also, since these are wear items, it’s worth considering the fact that automakers have to weigh the cost versus return when it comes to selecting parts like these for mass produced vehicles, which means you’re probably not getting the best part available, but one that meets the OEM’s established standard and can be produced in large quantities easily. The upshot is that there’s often plenty of room for improvement by turning to the aftermarket for a clutch replacement.
“Our clutches are all balanced within .25 oz, many OEM clutches are only balanced to .50oz,” explains Matt Polena of Fidanza. “Also, you can see between 10 to 60 percent increase in clamp load over OEM depending on the application, and even with an increase in clamp load, the V1 clutch will still maintain a stock to moderate increase in pedal feel, which makes it a great upgrade for any daily driver that has some extra horsepower.” Polena also points out that, for those competing with their vehicles, the factory clutch might not be enough to meet the rules of the sanctioning body. “Most Fidanza replacement discs meet SFI Specification 1.1 and are legal for use in racing organizations where SFI certification is required,” he explains.
When it comes to components like these for high performance applications, aftermarket companies that hone in on a specific forte often find ways to innovate and improve upon the established status quo. In terms of clutch design, this can mean not only better performance, but extended longevity as well.
The splines on our clutch discs are broached to a tighter tolerance than OEM. The tighter tolerance helps increase fitment to the transmission input shaft, increase the life of the spline and improve clutch release. -Matt Polena, Fidanza Performance
Rated at up 660 pound-feet of torque, the V1 clutch for the ’97-’04 C5 Corvette (PN 698571) is designed to handle significantly more grunt than the 350 lb-ft of torque that the car’s LS1 was generating in stock form. “The key to handling more power is stronger materials,” says Polena. “We offer a stronger diaphragm, drive straps, and top grade rivets. These are all used when needed to help strengthen the pressure plate and discs to prevent breakage and help handle significantly more power. We also heat-treat the diaphragms and the contact bearing release area is hardened to help reduce wear.”
In the past, improved clutch horsepower tolerance versus stock often came at a cost – not just in terms of expense but in clutch effort and feel as well – resulting in less commute-friendly drivability. In the case of the V1 clutch Fidanza’s engineers took these concerns into account during the design phase, but at the end of the day, a lot of it also comes down to simply picking the right part for the application. “A big part of drivability is the friction material and selecting the correct clutch for your driving style,” Polena explains.
“Fidanza does not offer harsher disc materials like sintered iron, we keep things simple by offering two types of disc materials. Our V1 clutches offer a full faced organic disc. This disc is sprung hub and a step above your OEM disc, offering quicker shifting, increased strength and heat tolerance. If a driver has issues with drivability, the problem typically stems from running the incorrect clutch, as many drivers ‘over buy’ clutches. We see people purchase clutches that can handle a 1,000 ft-lbs of torque, but their vehicle only produces 500 ft-lbs of torque, and this leads to drivability issues.”
The Qwik-Rev Option
If a driver has issues with drivability, the problem typically stems from running the incorrect clutch, as many drivers “over buy” clutches. We see people purchase clutches that can handle a 1,000 ft-lbs of torque, but their vehicle only produces 500 ft-lbs of torque – this leads to drivability issues. -Matt Polena, Fidanza Performance
“One of the key advantages of purchasing a Fidanza Qwik-Rev kit is the cost savings,” says Polena. “You can save a couple bucks by purchasing the clutch and flywheel together as opposed to buying the parts separately.”
But beyond cost savings, the Qwik-Rev kits provide additional piece of mind that the new parts are going to function with factory-like refinement. “The Qwik-Rev kits also come balanced as one unit to help reduce any possible noise or vibrations,” says Polena. “If purchased separately, it would be up to the customer to have the flywheel and clutch balanced together, so it’s a great option if you are worried about increased noise with a new flywheel. Also, anytime you move to a lightweight flywheel you’ll hear warnings about ‘lightweight flywheel noise’ or more correctly called ‘gear rattle.’ Our Qwik-Rev kits are set up with a sprung hub clutch disc which helps to dampen and absorb the rattle.”
The lightweight flywheel and matched parts also benefit performance in general, so they’re a common choice for vehicles that regularly see use in motorsport as well. “We see a lot of different applications that benefit from our Qwik-Rev Series – everything from autocross, road racing to even drag racing,” Polena says.
Replaceable Flywheel Friction Surfaces
Many flywheels are able to be resurfaced, however resurfacing can lead to engagement height issues, slipping and trouble getting into gear. Fidanza’s replaceable friction surface eliminates that issue. The replaceable friction surface is a feature that is incorporated into all Fidanza flywheels and easily replaced when needed.
When the time comes, drivers can purchase the replaceable friction surface for a fraction of the cost of a new flywheel. Fidanza’s replacement kits come with military grade aerospace fasteners featuring mechanical, self-locking nuts with built-in washes for reliability and strength. The friction plate itself is constructed of high quality 1050 steel and are pickled and oiled to deliver superior longevity and disc engagement.
After getting Project Y2K back to the shop, we got the installation of the Fidanza V1 clutch underway by first putting the car up on a lift and removing the exhaust system so we could get to the torque tube that’s entombed in the transmission tunnel under a protective shield.
Once the torque tube was exposed, we noticed that the long-tube headers we’re using would likely have to be moved out of the way to get the clutch out.
Once the headers were unbolted out of the way we were ready to turn our attention to the rear suspension and transaxle cradle, which needed to be unbolted so the torque tube could be moved back, allowing us to remove the old clutch in turn. This involves unbolting the upper control arms, shocks, and all the electrical connections on the transaxle. The calipers are hung separately, and the transaxle is secured to a trans jack with tie downs to prevent it from making an unexpected exit.
The slave cylinder from the line that leads to the clutch master also needs to be released by depressing the white ring with two flat blade screw drivers, which should pop it free and allow it to separate.
After moving back the torque tube and removing the old flywheel and clutch, the new parts could start to be installed, beginning with the new flywheel. We decided to reuse the existing pilot bushing since it was fairly new and in good shape. After maneuvering the new pressure plate and clutch disc into place and aligning everything, it was simply a matter of fastening everything down to spec and reinstalling the parts that had been removed to access the clutch assembly.
Has the clutch in your ride seen better days? Give the folks at Fidanza Performance a buzz and find out how you can improve your transmission’s performance while adding durability with their V1 and V2 series clutches, replaceable flywheel friction surfaces, and Qwik-Rev kits.