[Junkyard Dog]

Those of you who read Car Craft and Hot Rod will recall recent articles about a Ford Maverick street car and its quest for glory on the quarter mile. One thing I noticed last month was that the owner swapped in a clutch that had slippage built into it, stating that a clutch that grabs too hard was in some sense a bad thing. Having always thought a clutch should grip as tightly as possible, I was somewhat taken aback. Can anyone clue me on on the rationale? Is anyone here using this same philosophy?

[Junkyard Dog]

Those of you who read Car Craft and Hot Rod will recall recent articles about a Ford Maverick street car and its quest for glory on the quarter mile. One thing I noticed last month was that the owner swapped in a clutch that had slippage built into it, stating that a clutch that grabs too hard was in some sense a bad thing. Having always thought a clutch should grip as tightly as possible, I was somewhat taken aback. Can anyone clue me on on the rationale? Is anyone here using this same philosophy?

[ERIC17621]

I read the same article, and I believe what they are referring to was just a little bit of slip while the clutch is engaging. It is not slipping the whole way down the track, just until the car starts rolling a little bit. Since the engine is doing 5000+ rpm, and the wheels are doing 0, if the clutch engages immediately upon release, and grips like a 3 ton gorilla, then either you are going to see the tires go up in smoke, or the engine will bog. The benefit came from a little clutch slippage, allowing him to keep the engine rpm's up in the power band, while the tires are speeding up to the same speed as the engine is trying to turn them at. From then on, the clutch is engaged, and no longer slipping.
Since with a stick you don't have the luxury of a torque converter to help coordinate the engine and tire speeds, he found it beneficial to have a clutch that "slipped" some, and in effect acted slightly like a torque converter at launch.

[Junkyard Dog]

That was sort of what I figured, but I never see this feature advertised on any street clutches. I do see it advertised on race clutches (pro stock clutches get the slip dialed in). What clutches do this and will serve street duty as well as the track?

[White Warrior]

The type of clutches that are designed to slip on initial takeoff use a sintered iron disk with and adjustable pressure plate. This is what I use, made by McLeod.
The sintered iron will slip when it is cold but the hotter it gets the better it grips.
The problem with the normal organic disk is that it is just the opposite,grips best when cold and slips when hot. It also requires more plate pressure than a sintered iron setup. The pressure plat is adjustable from about 500 to 1100 lbs and is usually run somewhere's in the middle of that range. I don't know how they would be on the street, for racing they need adjusting after every few runs.
The Centerforce Dual Friction clutch is a half metallic, half organic disk that may give you what you want.

[fastgto]

I use the Centerforce Dual Friction clutch. I love it, it works for me. 1964 G.T.O. 467ci.
T.K.O.600 5spd.