Need help choosing the correct clutch for your 1979-93 Fox Body Mustang? LMR.com gives you the information to make the right choice in clutch and flywheel!
With the 1979-1993 Mustang, there are many different types of clutches and flywheels that you can purchase for your Fox Body. Depending on the intended driving style and horsepower output of your Mustang will determine the clutch and flywheel that you will want to use in your Mustang. This article will divide the clutches into four categories, flywheel materials, balance, and SROD/T5 10.5 clutch conversion, to help you choose which clutch will best fit your driving style and horsepower ratings.
Horsepower Range:
Up to 300 HP*
Modifications:
mild bolt-on applications, including headers, cold air intakes, throttle bodies, underdrive pulleys, etc.
Driving Style:
Daily driver with the above modifications
Tire Types:
All-season or summer performance tires, excluding drag radials
These clutch kits will utilize a clutch disc with an organic friction material to provide an effortless factory pedal feel and reliable driving characteristics. This group of clutches will work well with OEM or upgraded rear-end gear ratios. Clutch chatter will not be evident with these stock/OE-style clutches.
Horsepower Range:
300-400 HP*
Modifications:
Performance heads, camshafts, intake manifolds, mild stroker setups
Driving Style:
Daily driver with more serious engine modifications.
Tire Types:
All-season or summer performance tires, excluding drag radials
These clutch kits will utilize a disc with upgraded organic friction material and a pressure plate with increased clamping force. You can expect very smooth clutch engagement with a moderate increase in the pedal effort to provide consistent driving characteristics. Depending on rear gear ratio, flywheels, and mounts - chatter may/will be evident with a performance-oriented clutch.
Horsepower Range:
400+ HP*
Modifications:
Max effort stroker naturally aspirated engines, supercharger, turbocharger, nitrous
Driving Style:
Performance street to dedicated track
Tire Types:
All-season, summer performance, drag radials, and slicks
These kits will utilize a clutch disc with a dual friction material or puck-style design. The construction of these clutch discs can consist of organic material on one side, ceramic on the other, or ceramic on both sides. Due to the increased pressure plate clamping forces, these single-disc clutch kits will provide a harder pedal effort, with chattering expected during the engagement. Depending on the rear gear ratio, flywheels, and mounts - chatter may/will be evident with a performance-oriented clutch.
Horsepower Range:
400+ HP*
Modifications:
Performance heads, camshafts, intake manifolds, mild stroker setups, max effort stroker naturally aspirated engines, supercharger, turbocharger, nitrous
Driving Style:
Daily-driver street to dedicated track
Tire Types:
All-season, summer performance, drag radials, and slicks
These kits are great for Mustangs with high horsepower who want to keep a lighter pedal effort for daily use. Twin disc clutches utilize two clutch discs to provide a light pedal effort and smooth engagement without sacrificing the power they can withstand. Clutch chatter usually is very minimal with dual disc applications. These kits utilize clutch discs with an organic friction material or puck-style design. Depending on the rear gear ratio, flywheels, and mounts - chatter may/will be evident with a performance-oriented clutch.
Note*: Horsepower rating will vary depending on the brand. Horsepower rating is generally rated at the engine, not the wheels unless otherwise stated.
Flywheel material can play an important role in how your engine and clutch behave. The weight of the flywheel will depend on the material in which the flywheel is manufactured. Use the below guide to choose the flywheel material best suited for your driving style.
Benefits:
Decreased pedal effort, durable material, cost-effective, OEM material
Drawback:
High weight decreases engine responsiveness, slow heat dissipation
Horsepower Range:
Stock-300 HP*
Modifications:
Mild bolt-on applications, including headers, cold air intakes, throttle bodies, underdrive pulleys, etc.
Driving Style:
Daily-driver street to performance street
Tire Types:
All-season, summer performance excluding drag radials
Ford provided cast iron flywheels as the material of choice for their durability and to help keep costs down in manufacturing. Cast iron is great for the Mustang looking to keep stock driveability and wanting an OEM-style replacement.
Benefits:
Lighter than cast iron, highly durable material, high RPM capable
Drawback:
Higher price than cast iron, heavier than aluminum
Horsepower Range:
300+ HP*
Modifications:
Mild bolt-on applications to high horsepower setups
Driving Style:
Daily-driver to dedicated track
Tire Types:
All-season, summer performance, drag radials, slicks
Billet steel and chrome-moly are the best choices for a performance upgrade for the everyday car all the way to the dedicated track car. These flywheels will be lighter than cast iron, highly durable for everyday use, and have increased RPM range, with really the only drawback being that they are heavier than aluminum. These are the best choice in performance upgrades for the everyday driver.
Benefits:
Extremely lightweight, increased engine responsiveness
Drawback:
Decreased durability over steel and cast iron, more pedal effort
Horsepower Range:
300+ HP*
Modifications:
Mild bolt-on applications to high horsepower setups
Driving Style:
Performance driver to dedicated track
Tire Types:
All-season, summer performance, drag radials, slicks
Aluminum flywheels are great for improving the performance of your Mustang by removing rotational mass from the engine. The drawback is that aluminum is not as durable as cast iron as well as the lighter weight requires the engine to be revved more when letting the clutch out. A daily driver can use aluminum flywheels, but the increased clutch work makes it better suited for a weekend warrior or track car.
Choosing the correct flywheel balance will be crucial for preventing vibrations in your engine. Whether you have a factory engine or stroker depends on whether you need a 0oz, 28oz, or 50oz. Use the guide below to help you choose which balance is correct for your application!
Application**:
Stroker motors using internal/0oz balancing
These will be reserved for stroker motors utilizing the internal balancing on the crankshaft. No factory 1979-93 Mustang will have this on the factory engine.
Application**:
351W or strokers utilizing 28oz external balancing
Ford utilized 28oz balance on most 351W based engines from the factory. There are also many strokers for the 302 that will utilize 28 external balancing. If you have a stroker, it would be best to double-check your balance before purchasing a flywheel.
Application**:
1979-1993 Mustang with Factory 5.0L/302
Strokers utilizing 50oz external balance
Ford utilized a 50 oz balance on most 302W-based engines from the factory, including the 1979-1993 5.0L Mustang and Cobras. There are also many strokers for the 302 that will utilize 50oz external balancing. If you have a stroker, it would be best to double-check your balance before purchasing a flywheel.
** Note: It is always best to verify your engine balance if you are not positive if engine work has been done to your Mustang. Matching the balancer on the front of the engine is also key to getting the correct flywheel for your engine. Failure to do this will cause vibrations and damage to your engine. When in doubt, consult an engine builder or machine shop.
1979-1983 V8 Mustangs utilizing 4-speed SROD transmission and 1983-1985 Mustang 5.0L came from ford with a 10" clutch and flywheel. The 10" clutch is not very common when finding replacements, and a 10.5" clutch is a common upgrade for these Mustangs. This can be done by simply purchasing the following parts:
It is always best to replace the pilot bearing, throwout bearing, clutch fork, and pivot stud when changing your clutch.
