Black Magic Long Style Clutch Units

Our traditional Long Style clutch units are commonly used in heads-up drag racing, bracket racing, grudge racing, salt flat land speed, standing mile, truck & tractor pull, as well as Pro Street and Drag Week type street strip. 

Our clutch units all have available applied pressure information gained through in-house Clucth Dyno testing and developmets. This allows us to know exactly how much pressure is applied at all times through your given rpm range. Adjustable or "Slipper" style clutches are designed to apply less pressure at lower rpm, and gain additional pressure as more rpm is achieved. Additionally, by adding or removing Counter Weight (Nuts/Bolts/Washers), measured in grams we are able to change the rate of applied pressure applied over rpm. The static Base Pressure is adjusted by turning each base adjuster (Generally 6 springs), to increase or decrease pressure as desired.

As an example using the base and counter weight charts above and the car infomation below:

Car: 3200 lbs, 875 hp, 8800 shift rpm, 5000 launch rpm, 28x10.5 Tire, 3.05 First Gear, 5.00 Rear Gear

Launch RPM: 5000

Base: 3 Turns = 572 lbs

CW: 30g -23.382 lbs per gram (23.382 X 30) = 701.46 LBS

Base and CW together = 1273.46 lbs Total Pressure

If we target a Lock-Up Rpm of 7400 rpm:

Base: 3 Turns = 572

CW: 30g - 52.61 lbs per gram (52.61 X 30) = 1578.30 Lbs

Base and CW together = 2150.30 Total Pressure

With this you can see how you would leave at one pressure (1273.46) allowing for slippage, while achieving an additional 876.84 lbs of pressure to lockup at a desired rpm.  By adjusting the Base/CW balance and totals, you can effectivly determine exactly when you want the clutch to lock up. While seat of the pants tuning you can definately make signifiicant gains in performance, however when logging engine rpm, driveshaft rpm and clutch rpm we can specifically determine the exact point of lockup. Once you know the amount of pressure required to lock the clutch 1 to 1 with engine rpm, you can easily calculate and adjust the total pressure desired at a given rpm.

Our Stamped Steel Style Long Style units are available for all applications using larger tooth ring gear counts.  (GM/Chevy 168t and larger, Ford 164t-176t-184t, Mopar 143t, Pontiac 166t) - Additionl applicatins available upon request.

Complete units are all built specifically to the customer's needs. We bulld all clutchesto order rater than off the shelf generic units.

Options:

Pressure Ring: Ductile Iron or 7075 Grade Aluminum w/segmented steel heat shields

Flywheel: Billet Steel or 7075 Grade Aluminum w/segmented steel heat shields

Spring Options: Base is Yellow (360 lb) / Heavy is ed (660)        ** Additional Options Available.

Billet Levers: Standard Billet Levers  /  Black Magic Divination Levers (w/inboard cw options)

Single and Dual Disc

Pricing: (All at basep ricing)

Single Disc Billet Steel and Ductile Pressure Plate: $1450.00  

Single Disc Segmented Aluminum Flywheel and Pressure Plate: $1900

For Twin Disc add $450.00