Tilton 7.25" OT-II Metallic Racing Clutch Covers

Tilton’s 7.25″ OT-II metallic racing clutches, designed primarily for road racing, circle track, open wheel and formula applications, Tilton’s 7.25″ OT-II metallic racing clutches offer the low moment-of-inertia, high torque capacity and reliability necessary for the most demanding racing applications. These features have made metallic clutches the most common clutch type used in road racing and circle track racing. Metallic clutches are not recommended for street use. These features make Tilton’s 7.25″ OT-II metallic racing clutches popular in the applications below:

• Road Racing
• Circle Track
• Open Wheel
• Track Racing
• Street Circuit

Tilton uses a color system for indicating the angle and weight of the clutch spring, which has an effect on release load and torque capacity for the clutch. The exact values for each color vary depending on the type of clutch, so be sure to check the charts below to find exact measurements.

1 Plate Clutch Specifications:
Weight**:  5.1 lbs / 2.3 kg
M.O.I.**:  44.1 lb-in² / .0130 kg-m²

2 Plate Clutch Specifications:
Weight**:  7.5 lbs / 3.4 kg
M.O.I.**:  66.3 lb-in² / .0195 kg-m²

3 Plate Clutch Specifications:
Weight**:  9.9 lbs / 5.4 kg
M.O.I.**:  87.6 lb-in² / .0258 kg-m²

* Values listed are typical for release bearings with the recommended 44mm contact diameter. Larger contact diameters will increase release load.

** Weight and M.O.I. include pressure plate, carbon floater plates, carbon discs and steel hub, and may vary based on your particular spline.

 

Tilton offer two different styles of every clutch configuration: one designed to be compatible with a step-type flywheel and another for pot-type (“no-step”) flywheels. Step flywheels have a .100″ step for contact with the friction material of the clutch, so clutches made for this application will have a .100″ height difference between the bottom friction disc and the end of the clutch cover legs (the mounting points). Pot flywheels don’t have this step, so the friction disc and clutch cover legs will be flush on clutches designed for them.

Tilton’s metallic clutches are available with either a High Ratio or Ultra-High Ratio pressure plate. High Ratio pressure plates offer high clamp load over a wide wear range, while Ultra-High Ratio pressure plates provide 20% more clamp load and diaphragm spring travel (modulation). As seen on the graph below, the clamp load (or torque capacity) of the High Ratio pressure plate is relatively flat until .030″ (0.76mm) of wear; Ultra-High Ratio pressure plates offer a higher initial clamp load at a faster wear rate.

• Standard pressure plate ratio for Tilton metallic clutches
• Short release travel for quick engagement and faster shifting
• Flat clamp load curve for longest wear range

• 20% more release travel than High Ratio for improved modulation
• 20% more clamp load than High Ratio for higher peak torque capacity
• Clamp load drops more quickly with wear than High Ratio