KevinD
07-07-2009, 10:35 AM
This FAQ is aimed at those looking for more information regarding the clutch and flywheel in the Genesis Coupe. Most of the information here will be directed at those individuals.
What exactly is a Clutch/flywheel assembly?
This question has been answered numerous time by many different people. For a very good explanation, see this link at HowStuffWorks:
HowStuffWorks: Clutches (http://auto.howstuffworks.com/clutch.htm)
Which Clutch is right for me?
When most start our shopping for clutches, first impulses are to buy too much clutch. What does this mean? It means clutch shoppers typically buy a clutch that is either too strong or the wrong material for their intended use. This can have drive ability and reliability consequences that are unintended.
Clutches hold Torque NOT Horsepower
This is probably the most misunderstood concept about clutches. Clutch capacity is measured in the amount of torque it holds, not the amount of horsepower it can transmit. So when choosing a clutch, your torque number should guide your choice.
Choosing a clutch depends on many different things. As mentioned above, don't buy too much clutch. Look at clutches that fit within your desired torque goals. Once there, you'll find a myriad of materials, pressure plates, and other options that can make your head spin. On top of that add the additional noise, chatter, pedal feel, etc. and the choice is very daunting. We'll break it down further to help make it easier.
Note* The Genesis Coupe does not use a typical Clutch/Flywheel assembly. It uses a Clutch and Dual Mass Flywheel. This is important to know when shopping for aftermarket Clutch and Flywheel combinations
What are the different Clutch materials?
Clutches for automobiles are typically made of one of the following materials:
Organic: Metal-fiber woven into "organic", original-equipment style. Known for smooth engagement, long life, broad operating temperature, minimal-to-no break in period. Will take hard use, somewhat intolerant of repeated abuse (will overheat). Will return to almost full operational condition if overheated. Material is dark brown or black with visible metal fibers.
Kevlar: High-durability material more resistant to hard use. Engagement is similar to organic, but may glaze slightly in stop and go traffic, resulting in slippage until worn clean when used hard again. Higher temp range in general, but can be ruined from overheating; will not return to original characteristics if "cooked". Material is uniform yellow/green and may look slightly fuzzy when new.
Ceramic: Very high temperature material. Engagement is more abrupt. Will wear flywheel surface faster, especially in traffic situations. Due to it’s intrinsic properties, ceramic has a very high temperature range. Material is any of several light hues - gray, pink, brown.
Feramic: This unique clutch material is one that incorporates graphite and cindered iron. The result is a friction material that offers good friction coefficient, torque capacity, and smoothness of engagement.
Carbon: Very high temperature material. Engagement is more abrupt. Will wear flywheel surface faster, especially in traffic situations. Slightly more durable and flywheel-friendly compared to other aggressive clutch materials. Material is black.
Sintered Iron: Extremely high temperature material. Engagement is extremely harsh and is generally considered an “on/off switch” both due to it’s characteristics and the clutch types this material is generally associated with. It requires a special flywheel surface. Material is metallic gray in color.
Which Clutch material is right for me?
This all depends on your configuration and the clutch manufacturer specifications. Each clutch manufacturer has their own formulas and process. This means that an Organic clutch from manufacturer one may hold differently than an Organic clutch from manufacturer two. It's also important to note that clutch manufacturers rate their clutches to a "slip" rate. This is the amount of torque that can be applied to the clutch before it slips, not it's ability to withstand long term load. So if the model you are looking at is borderline to you goals, it will start slipping sooner than later.
In general most street cars use Organic clutches. Some high horsepower street cars use the stronger compounds, typically Kevlar and Ceramic.
What about Clutch construction?
Clutch construction is typically broken down into the following methods:
Full faced: Full round facing of material or full face with slight separations.
Segmented: Generally associated with Kevlar clutches. The missing sections are designed for greater heat dissipation.
Windowed: Generally associated with Kevlar clutches. The missing sections are designed for greater heat dissipation.
Puck (AKA Paddle): Generally associated with higher power vehicles. Careful consideration should be given prior to using this type of clutch.
Multi Disc (AKA Multi Plate): Generally associated with higher power vehicles. Careful consideration should be given prior to using this type of clutch.
http://www.wallpaperinstaller.com/scooby/clutch2.jpg
What is the difference between a Sprung and Unsprung Clutch?
Besides the obvious, a sprung clutch absorbs some of the drive line lash associated with clutch engagement. An unsprung clutch does not contain these springs.
http://www.wallpaperinstaller.com/scooby/clutch.jpg
What about increases in pedal pressure? What causes that?
Increased pedal pressure comes from the pressure plate of the clutch assembly. A clutch with a stronger pressure plate will increase the amount of pedal pressure required to engage and disengage the clutch. Now this doesn't mean you have to have a hard pedal with a strong clutch. Multi-Plate clutches use multiple clutch and pressure plates to achieve their holding power. This in-turn means that the pressure plates do not need to be as stiff to produce the same clamping force.
What is a Dual-Mass Flywheel?
A Dual-Mass flywheel is a essentially 2 flywheels in one, with a spring loaded center area that absorbs driveline vibration. Here is a great video explaining how it works using 3D models:
http://www.youtube.com/watch?v=YnaXB8q3uzQ
YnaXB8q3uzQ
What are the benefits of a Dual-Mass Flywheel?
Dual Mass Flywheels help deaden vibrations from the driveline, allowing for a smoother ride and reduce lash felt during shifts. For a touring car, this type of flywheels allows those who do not normally drive manual sports cars to enjoy their cars without feeling the harsh clutch engagement.
For performance purposes, a Dual Mass Flywheel is unnecessary and should be replaced. Not only is it very large, it makes the quick shifts required by motor-sports competition almost impossible, as there are now 2 flywheels that need to engage before power is transmitted.
Is it difficult to replace the stock Dual Mass Flywheel with a Standard Flywheel?
No. You can replace the stock Dual Mass Flywheel with any Standard single flywheel.
Editor's Note: At this time there are no known issues replacing the flywheel. This may change, however, as more information is gathered.
What exactly is a Clutch/flywheel assembly?
This question has been answered numerous time by many different people. For a very good explanation, see this link at HowStuffWorks:
HowStuffWorks: Clutches (http://auto.howstuffworks.com/clutch.htm)
Which Clutch is right for me?
When most start our shopping for clutches, first impulses are to buy too much clutch. What does this mean? It means clutch shoppers typically buy a clutch that is either too strong or the wrong material for their intended use. This can have drive ability and reliability consequences that are unintended.
Clutches hold Torque NOT Horsepower
This is probably the most misunderstood concept about clutches. Clutch capacity is measured in the amount of torque it holds, not the amount of horsepower it can transmit. So when choosing a clutch, your torque number should guide your choice.
Choosing a clutch depends on many different things. As mentioned above, don't buy too much clutch. Look at clutches that fit within your desired torque goals. Once there, you'll find a myriad of materials, pressure plates, and other options that can make your head spin. On top of that add the additional noise, chatter, pedal feel, etc. and the choice is very daunting. We'll break it down further to help make it easier.
Note* The Genesis Coupe does not use a typical Clutch/Flywheel assembly. It uses a Clutch and Dual Mass Flywheel. This is important to know when shopping for aftermarket Clutch and Flywheel combinations
What are the different Clutch materials?
Clutches for automobiles are typically made of one of the following materials:
Organic: Metal-fiber woven into "organic", original-equipment style. Known for smooth engagement, long life, broad operating temperature, minimal-to-no break in period. Will take hard use, somewhat intolerant of repeated abuse (will overheat). Will return to almost full operational condition if overheated. Material is dark brown or black with visible metal fibers.
Kevlar: High-durability material more resistant to hard use. Engagement is similar to organic, but may glaze slightly in stop and go traffic, resulting in slippage until worn clean when used hard again. Higher temp range in general, but can be ruined from overheating; will not return to original characteristics if "cooked". Material is uniform yellow/green and may look slightly fuzzy when new.
Ceramic: Very high temperature material. Engagement is more abrupt. Will wear flywheel surface faster, especially in traffic situations. Due to it’s intrinsic properties, ceramic has a very high temperature range. Material is any of several light hues - gray, pink, brown.
Feramic: This unique clutch material is one that incorporates graphite and cindered iron. The result is a friction material that offers good friction coefficient, torque capacity, and smoothness of engagement.
Carbon: Very high temperature material. Engagement is more abrupt. Will wear flywheel surface faster, especially in traffic situations. Slightly more durable and flywheel-friendly compared to other aggressive clutch materials. Material is black.
Sintered Iron: Extremely high temperature material. Engagement is extremely harsh and is generally considered an “on/off switch” both due to it’s characteristics and the clutch types this material is generally associated with. It requires a special flywheel surface. Material is metallic gray in color.
Which Clutch material is right for me?
This all depends on your configuration and the clutch manufacturer specifications. Each clutch manufacturer has their own formulas and process. This means that an Organic clutch from manufacturer one may hold differently than an Organic clutch from manufacturer two. It's also important to note that clutch manufacturers rate their clutches to a "slip" rate. This is the amount of torque that can be applied to the clutch before it slips, not it's ability to withstand long term load. So if the model you are looking at is borderline to you goals, it will start slipping sooner than later.
In general most street cars use Organic clutches. Some high horsepower street cars use the stronger compounds, typically Kevlar and Ceramic.
What about Clutch construction?
Clutch construction is typically broken down into the following methods:
Full faced: Full round facing of material or full face with slight separations.
Segmented: Generally associated with Kevlar clutches. The missing sections are designed for greater heat dissipation.
Windowed: Generally associated with Kevlar clutches. The missing sections are designed for greater heat dissipation.
Puck (AKA Paddle): Generally associated with higher power vehicles. Careful consideration should be given prior to using this type of clutch.
Multi Disc (AKA Multi Plate): Generally associated with higher power vehicles. Careful consideration should be given prior to using this type of clutch.
http://www.wallpaperinstaller.com/scooby/clutch2.jpg
What is the difference between a Sprung and Unsprung Clutch?
Besides the obvious, a sprung clutch absorbs some of the drive line lash associated with clutch engagement. An unsprung clutch does not contain these springs.
http://www.wallpaperinstaller.com/scooby/clutch.jpg
What about increases in pedal pressure? What causes that?
Increased pedal pressure comes from the pressure plate of the clutch assembly. A clutch with a stronger pressure plate will increase the amount of pedal pressure required to engage and disengage the clutch. Now this doesn't mean you have to have a hard pedal with a strong clutch. Multi-Plate clutches use multiple clutch and pressure plates to achieve their holding power. This in-turn means that the pressure plates do not need to be as stiff to produce the same clamping force.
What is a Dual-Mass Flywheel?
A Dual-Mass flywheel is a essentially 2 flywheels in one, with a spring loaded center area that absorbs driveline vibration. Here is a great video explaining how it works using 3D models:
http://www.youtube.com/watch?v=YnaXB8q3uzQ
YnaXB8q3uzQ
What are the benefits of a Dual-Mass Flywheel?
Dual Mass Flywheels help deaden vibrations from the driveline, allowing for a smoother ride and reduce lash felt during shifts. For a touring car, this type of flywheels allows those who do not normally drive manual sports cars to enjoy their cars without feeling the harsh clutch engagement.
For performance purposes, a Dual Mass Flywheel is unnecessary and should be replaced. Not only is it very large, it makes the quick shifts required by motor-sports competition almost impossible, as there are now 2 flywheels that need to engage before power is transmitted.
Is it difficult to replace the stock Dual Mass Flywheel with a Standard Flywheel?
No. You can replace the stock Dual Mass Flywheel with any Standard single flywheel.
Editor's Note: At this time there are no known issues replacing the flywheel. This may change, however, as more information is gathered.