Petroworks Performance Clutch

Nov. 01, 2005 By Geoff Beasley
Bronze side of friction disk

Suzuki owners are lucky to have such a broad selection of various aftermarket and factory replacement clutches available. For the extreme off-roading that many Samurai owners like to do with their vehicles, the stock clutch is inadequate and quickly wears out. The use of larger tires and locking differentials only makes the problem worse, so clutch replacement is an inevitable job at some point in the Samurai?s life.

Stock replacement clutches work sufficiently well for their intended purpose, but for serious off-road use an upgraded clutch is a worthwhile investment. Until recently, the best clutches available for the Samurai were from Centerforce, the best of which is the Dual Friction. But when Gary Munck of Petroworks Offroad Products was left temporarily immobile when the Centerforce Dual Friction in his Samurai overheated, he decided that development of an even better clutch was a worthwhile investment.

Ceramic compound side of friction diskPetroworks went to a well-known clutch manufacturer to design the best clutch available for the Samurai, one that would stand up to serious off-road usage and to the torque of their turbo diesel engine swap. They developed a proprietary dual friction clutch that utilizes a ceramic compound on one side of the friction disk and bronze pads on the other. After two years of development, it was time for the ultimate test.

Setting down a baseline for comparison, Gary was able to smoke the Centerforce in his Samurai until it no longer grabbed. They then swapped it out for one of the new Petroworks High Performance Clutches, and repeated the clutch-smoking. No matter how hard he tried, the clutch still grabbed. It was then that they decided that the clutch was ready for the general public.

In my Samurai, I had found great success with a Centerforce Gold clutch that had withstood five years of off-road use in my Samurai. Its performance had degraded as it wore out, so while installing my new engine I decided it was time for a new clutch. I chose a stock replacement clutch and immediately found that it was not good enough; my big tires and powerful engine were more than the clutch could handle, even with the help of a GRS2 transfer case to ease the work the clutch had to do. Off-road driving would quickly cause the clutch to smoke and fade, and even a single fast start on the street was enough to get the clutch stinking and slipping. A better clutch was an absolute necessity.

I considered going back to a Centerforce, but after talking with Rudy at Petroworks I was convinced that their new High Performance Clutch would be a better choice. Petroworks had their new clutch shipped to me within two days and I quickly installed it.

petroclutch03.jpg (24742 bytes)Like most modern high performance clutches, high pedal effort from Petroworks? clutch is not necessary for its strong clamping power. In fact, the pedal effort feels the same as with both the stock replacement clutch and the Centerforce I had previously installed. In everyday driving it feels like a normal clutch, but work it hard and it is readily apparent that this is a very strong clutch.

Clutch take-up is very progressive and easily modulated. Around town and on the highway, the clutch makes for very smooth driving. Its progressiveness also made it easy for my friend to learn how to drive a manual transmission in an afternoon. Off-road, however, is where this clutch really shines.

petroclutch04.jpg (43272 bytes)The linear clutch take-up makes slow-speed driving ? such as rockcrawling ? very easy for both the driver and the drive train. Slipping the clutch for just the right amount of torque transfer allows for the smoothest possible ride and minimizes driveline stress. Too much of this clutch-slipping, however, quickly overcomes most clutches. The Petroworks clutch was made specifically for such abuse.

Although I haven?t tried to burn up the clutch and explode my drivetrain just to see how much abuse this clutch can handle, I have had plenty of opportunities to expose any weaknesses in this clutch?s design. I am happy to say that I found only one minor quirk. Under slow acceleration with light clutch slipping, a slight amount of clutch chatter is apparent. With the inherent driveline slop from the locker in the differential, the clutch will cyclically grip-slip-grip until either the engine and transmission speeds match or the clutch is slipped more firmly. I spoke with Petroworks about the clutch chatter, and they had not heard of anybody else experiencing it. Regardless, it is just a minor quirk that does not affect the livability of the clutch.

No matter how big the rocks, how steep the hill, or how rough the trail, I have not been able to get this clutch to let out even the slightest odor. It has never smoked; never faded. And on steep hill-climbs, sand dunes, and other full-throttle applications, it never slips. It just does what it is supposed to do, no matter what the trail conditions are like.

I do not hesitate to recommend the Petroworks High Performance clutch to anyone who spends much time off-road. It outperforms every other clutch on the market. The stock clutch is adequate for on-road use with stock tires, but even Samurais that stick to the pavement will benefit from this upgraded clutch.

Available for $225, only from Petroworks.

--Geoff Beasley Newsletter
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