If you are unfamiliar with the brand SPEC Clutch, then you should know they are a great company that specialize in manufacturing high-quality automotive clutches and flywheels, in addition to a few other performance and driveline components.
Unfortunately, a lot of people don’t think their clutch until it wears out, and they are in the need for a new one. Some folks realize the need for a clutch replacement earlier, but either way, there is certainly some myths and misinformation out there and David Norton wrote an interesting piece and we would really thought it was of serious value to share with our readers.
Norton explained, “I wanted to address the fallacy that lightweight parts adversely affect torque output, as well as outline other benefits. Racers and car builders understand the benefits and drawbacks of drastic changes in inertia through firsthand experience with their specific setups. However, those without the time and resources to test often turn to others who may also not know, particularly those who distribute bad information via internet and social media based on opinion or something they have heard.
I think most are in agreement that lightweight parts allow an increased rate of rev and, therefore a bump in horsepower. The horsepower increase varies from driveline to driveline, and we have seen it range from 5 to 30 wheel horsepower in dyno testing. Gains are evident in stock as well as modified applications; when you reduce the amount of power it takes to propel the driveline, the gains will take place regardless of the supporting parts.
The controversy seems to arise when speaking about torque and drivability. We have never seen a loss in torque with lightweight parts on the dyno, and excellent drivability can be maintained if the lightweight parts are properly matched to the car (displacement, vehicle weight and gearing are factors we use to make driveline weight reduction recommendations).”
Clearly David Norton, and the guys at SPEC Clutch know the technology, and are confident in its benefit for you and your machine. Knowledge is great when you can learn from a tested source, but what really drives all of this home aside from getting to feel a difference behind the wheel for themselves, are dyno results.
Norton continued, “We sourced a local and 100 percent stock 2011 Corvette Grand Sport for a dyno comparison using one of our popular lightweight street clutch and flywheel packages. The stock, low mileage, daily driver had a properly functioning original clutch, flywheel and hydraulic system. For good measure, we installed a replacement slave cylinder and one of our remote bleeders along with our billet aluminum flywheel and Stage 1 10.5-inch clutch packages (vs the OE 11.875-inch).
The new package weighs in at 29 pounds, versus the stock setup at 57.4 pounds. We manufacture a lightweight package in the stock diameter as well, but our 10.5-inch unit offers additional benefits such as reduced mass on the torque tube and input shaft for superior shifting, a reduction in stress and requirement at the release bearing, and a higher torque capacity – all of this is possible on a clutch that has a smaller diameter than the stock unit, with the same material.
With identical dyno loading, and despite a 19 percent higher humidity during the post-install dyno pull, the clutch and flywheel package netted 7.7 peak rear wheel horsepower, and maintained a majority of that peak gain across the curve. The gains are an advantage regardless of the RPM. Even more impressive was the 13.4 lb-ft of torque gained at the rear wheels – Not bad for a maintenance part.
This comparison illustrates what we term ‘free power’, because the parts are less stressful on the engine and driveline, while providing a considerable performance and shifting advantage, and with better drivability than the stock unit. The clutch requires less pedal effort, a cleaner shift and smooth and more consistent engagement than the OE ratcheting unit.”
Needless to say, the fact that you can actually gain a fair amount of horsepower and even more torque in addition to all of the gains that come from installing an aftermarket performance clutch is just awesome. There are several products on the market which are designed solely to increase power, and yet some of them only show a significant increase at peak RPM. As Norton mentioned, the power gains from the SPEC clutch increase power all across the horsepower and torque curves. Moreover a faster revving, more responsive engine and clutch system is something that is useful in more than just producing peak power.
Whether or not you need a new clutch for your car, check out SPEC online or give them a shout and see what they can do for you!