General Guidelines for "Stages" of Spec Clutches All Clutch kits include a high clamp load, true high performance pressure plate, a clutch release or throw-out bearing, a pilot bearing (where needed), and an alignment tool. The difference between the stages is primarily in the clutch discs.
Use: High performance street driving, light drag strip or road racing, commercial duty or fleet service vehicles. Normally these kits provide 25% to 30% more load capacity than stock. These clutch discs feature steel backed woven high performance organic lining, very similar to original equipment but much higher quality. They will engage and drive as smooth as a stock clutch and the clutch pedal will have a nice firm (not stiff) feel to it. Use: High performance street driving, light to medium duty drag strip or road racing use. Great for commercial duty or fleet service vehicles, SUVs, and other extreme truck applications. Normally these kits provide 50% to 65% more load capacity than stock. These clutch discs feature segmented kevlar lining and sprung hubs. They will engage and drive virtually as smooth as a stock clutch and the clutch pedal will have a nice firm (not stiff) feel to it. Besides being extremely tough, Kevlar clutches are known for being long lasting too. Use: Extreme High performance street use, medium to heavy duty drag strip or road racing use. Some commercial duty or fleet service vehicles, SUVs, and other extreme truck applications. Normally these kits provide 80% to 100% more load capacity than stock. Used in conjunction with our lightweight option(s) and aluminum flywheels. Stage 3 kits are our most popular kits for serious road race use. The sprung hubs on these discs greatly reduce impact and shock transmitted to your driveline. These clutch discs feature a hybrid material that is a combination of carbon and ceramic. Stage 3 discs will have sprung hubs. They will have a quick but smooth engagement. These clutches require a 400 mile break-in period before full throttle use. If you are going to use a car for street use you need a sprung hub. These clutches are extremely tough and "streetable" too. Most Stage 3 discs are available in either 4 or 6 puck design to suit your specific needs. Use: The Ultimate Street-Strip Clutch! Just released "streetable" clutches don’t come any tougher than these. Super High performance street driving, medium to all out drag strip or road racing use. Normally these kits provide 170% to 250% more load capacity than stock. Used in conjunction with our lightweight option(s) and aluminum flywheels Stage 3"I" kits are sure to be a hit with the very high horsepower road race crowd. The sprung hubs on these discs greatly reduce impact and shock transmitted to your driveline. These clutch discs feature a new material that is a combination of carbon and metallic. Stage 3"I" discs will have sprung hubs. They will have a quicker engagement than the standard Stage 3 clutch but are still smooth enough for street use. These clutches require a short break-in period before full throttle use. If you are going to use a car for street use you need a sprung hub. These are the toughest "streetable" clutches you will find. Most Stage 3"I" discs are available in either 4 or 6 puck design to suit your specific needs. These are awesome clutches with great pricing too. You will have to call for pricing, these are too new to be in the catalog . Use: Road Racing & Drag Racing! Used in conjunction with our lightweight option(s) and aluminum flywheels. Stage 4 kits are very popular kits for serious road race use. These kits are also a great choice for drag racing. Normally these kits provide 80% to 110% more load capacity than stock. These clutch discs feature a hybrid material that is a combination of carbon and ceramic. Stage 4 discs will have rigid unsprung hubs. They will have very quick engagement. These clutches require a break-in period before full throttle use. Most Stage 4 discs are available in either 3 or 6 puck design to suit your specific needs. Use: Very Serious Road Racing & Drag Racing! Used in conjunction with our lightweight option(s) and aluminum flywheels. Stage 4"I" kits are our sure to be a hit with the very high horsepower road race crowd. These kits are also a great choice for drag racing. Normally these kits provide 170% to 250% more load capacity than stock. These clutch discs feature a new material that is a combination of carbon and metallic. Stage 4 discs will have rigid unsprung hubs. They will have very quick engagement. These clutches require a break-in period before full throttle use. Most Stage 4 discs are available in either 3 or 6 puck design to suit your specific needs. You will have to call for pricing, these are too new to be in the catalog . Use: Drag Racing! All out super strong drag racing clutch. Extremely high torque ratings. Normally these kits provide 175% to 250% more load capacity than stock. These clutch discs feature an iron unsprung disc. Basically Stage 5 is more like an off/on switch than a clutch. When these clutches engage you will know it! SPEC’s Lightweight Option can be added to just about every clutch we offer for an additional $79.00. Normally this will reduce the weight of the pressure plate by about 25%. Actual weight reduction comparisons will vary depending on the size and brand of the original components. If you are looking to reduce the inertial mass in your driveline this is the best bang for the buck you will find.
SPEC billet steel and billet aluminum flywheels are recommended as replacements for OEM cast steel flywheels in street high performance and racing applications. Your engine, gearing and vehicle weight are factors in determining which flywheel would be best suited for your application. Please inquire with a Clutch Express technical assistant for recommendations. Billet Steel SPEC billet steel flywheels are machined from the highest quality materials Billet Aluminum SPEC billet aluminum flywheels are also CNC machined and exceed SFI standards The plates are secured to the body by aerospace fasteners or stainless steel They are effective, durable and almost too pretty to install! |
