FAQ | EXEDY RACING CLUTCH

Frequently asked question from the inquiries are collected as “FAQ”.
Please check here before inquiring.

: I would like to obtain the EXEDY sports clutch catalog, but how much does it cost?

: Do I need conversion parts from pull type to push type for EXEDY clutches?; Do I need special parts or processing when EXEDY clutch is installed?; Why is there no sound (also known as rattle noise) when I disengage the clutch with the EXEDY HYPER SINGLE?; Do I need to break in the clutch after replacing it?; Flywheel of the EXEDY CARBON-R and COMPE-R has many holes, but how much lighter is it?; I have changed to twin clutch on BNR34, but sound is generating from the drive train during idling and accelerating. Is this a malfunction?; I have dropped the clutch disc, but is there any problem?; There are different types, “S METAL” and “R METAL”, of the EXEDY SINGLE SPORTS SERIES metal discs, but what are their characteristics?; I would like to purchase EXEDY products, but can I purchase it directly?; Why is the diaphragm spring matte finish for some of the EXEDY multi plate clutches?; There is a ring shaped parts between the cover assembly and the pressure plate of the EXEDY multi plate clutches, but what does this do?; Do I need to apply grease to the spline of the disc?; What is the tightening torque of the cover bolts?

: Is the “EXEDY Clutch” the same thing as the “Daikin Clutch”?

About requesting catalogs

I would like to obtain the EXEDY sports clutch catalog, but how much does it cost?

EXEDY sports clutch catalogs are sent out free of charge. Please send a request to the following address by E-mail or fax.
(The catalogs should arrive to you normally three to five days after we receive the request, but it may be delayed slightly due to a delay in the handling of shipping. We appreciate your understanding.)

Send your request to:
1) E-mail ：sbc@exedy.com
2) Fax: +81-72-821-6541 EXEDY Corporation, Sales Headquarters, Aftermarket Sales Department
* Please provide the following information with your request: 1. Postal code, 2. Address, 3. Your name, 4. Your age

About the products

Do I need conversion parts from pull type to push type for EXEDY clutches?

EXEDY is configuring pull type clutch for the pull structure cars, so it is not necessary.
Many of the other companies are only selling push type clutches. A conversion part is required to install that to the pull structure cars.

<Reference> Characteristics of the pull type clutch

(1) Disconnection of the clutch becomes more efficient because the warping of the cover by the force of the diaphragm spring generating the connection force is reduced by making the rigidity of the cover higher, and since the warping direction of the cover and direction of the release operation is the same.
(2) Since the disconnection of the clutch is efficient, it is possible to increase the lever ratio of the diaphragm spring compared with the push type, therefore the operational force of the lever can be reduced (lighter force on the pedal).
(3) With the EXEDY products, one-touch release equipment for the pull type release bearing is structured in the same way as the genuine clutches.

Do I need special parts or processing when EXEDY clutch is installed?: The EXEDY clutches are designed as a bolt-on, so there is no need for special modification.

Why is there no sound (also known as rattle noise) when I disengage the clutch with the EXEDY HYPER SINGLE?: This is because it has adopted the strap drive structure.
Rattle noise is generated in the boss drive type clutch.
With the boss drive structure, the pressure plate and the center plate becomes free when the clutch is disengaged.
The sound is generated when these plates rattle against the boss that is connected due to the fluctuation of the engine revolution. On the other hand, rattle noise is not generated with the strap drive structure because it is fixed with a strap plate (diaphragm spring) instead of the boss, so there is no rattling in the connection.
When the clutch is disengaged, a gap is created actively by the reaction force of the diaphragm spring, and it serves as enhancing the responsiveness of the disengagement.
This structure is currently adopted in many of the cars as genuine structure.

Do I need to break in the clutch after replacing it?: Always perform the break in of the clutch.
Only about 30% of the friction surface of the new clutch is in contact. The performance of clutch is exercised only when 100% of the friction surface is in contact.
It depends on the condition it is used, but drive for about 500 km in the urban condition to break in the clutch.
Repeat the starting with under 3000 RPM to break in the clutch.
Frequency of the clutch operation and load is too low in the highway driving or changing the gears, and break in of the clutch will not take place.
The point to make the clutch last is to break it in properly.

Flywheel of the EXEDY CARBON-R and COMPE-R has many holes, but how much lighter is it?

The weight of the flywheel is recognized as affecting the engine response, and the idea of inertia moment is important for this.
What affects the engine response is the “inertia moment“, which is a characteristic that tries to keep on rotating.
“Weight” is not completely wrong, but even with the same weight, “inertia” will be completely different even for the same weight if the “weight” is distributed close to the axis of rotation, or if it is distributed along the rim.
If you are considering the response to be important, it is recommended to select the one with low inertia.
Following is the comparison of the inertia of EXEDY products using the product for “R34 GTR” as an example.

	(1)CC+PP+IMP+FW	(2)CD	(1)+(2)
Genuine (single)	100	100	100
CARBON MULTI (twin)	43	36	42
COMPE-R (twin)	43	58	43
MULTI (twin)	48	80	50 or more

CC=clutch cover, PP＝pressure plate, IMP=center plate, FW=flywheel, CD=disc

I have changed to twin clutch on BNR34, but sound is generating from the drive train during idling and accelerating. Is this a malfunction?: This is not a malfunction.
Genuine flywheel for the BNR34 has special structure with a built-in damper.
This damper absorbs the fluctuation of the engine revolution, reducing the sound and vibration generated in the drive train, such as rattling sound of the transmission gear tooth, etc.
By replacing the genuine flywheel to other flywheel, the damper is removed also, so you will start to feel the sound and vibration generated in the drive train.
EXEDY is selling the clutch system “CARBON-D” that removed this “discomfort feeling” completely.
This product has a damper mounted on the center hub, reducing the sound and vibration from the drive train. This is a racing clutch that sought quietness and comfort.
Please try it.

I have dropped the clutch disc, but is there any problem?

It is recommended not to use it.
When you drop the disc, contact surface may be deformed, and it may cause judder or bad disengagement.
Clip, strap plate, or other parts may deform when you drop the clutch cover, which may also cause bad disengagement, judder, etc.
If you ever drop the product, contact EXEDY and send back the product.
We will check for any problem. (The customer is held responsible for round trip shipping costs.)

Inquiry and mailing address:
EXEDY Corporation, Sales Headquarters, Aftermarket Sales Department
1-1-1 Kidamotomiya, Neyagawa-shi, Osaka-fu 572-8570
TEL: +81-72-824-7138
E-mail ： sbc@exedy.com

There are different types, “S METAL” and “R METAL”, of the EXEDY SINGLE SPORTS SERIES metal discs, but what are their characteristics?

EXEDY has three types of metal discs, S, R, and P. (It may not be available depending on the model of the car)
They are representing the thickness of the metal facing materials, where S represents “thick”, R represents “thin”, and P represents “ultra thin”.
As its characteristics, thinner the disc, inertia of the disc is less, making the operability of the shifting better.
Thicker models have longer life expectancy in general, so select the model depending on your usage and taste.
Following are some references.
Use the EXEDY cover assembly compatible for each when replacing.

Clutch disc Facing material			Purpose of usage
Clutch disc Facing material			Street	Circuit	Drift	Rally	Gymkhana	Dirt track
Organic (asbestos-free)
Metal	S METAL	Thick metal
	R METAL	Thin metal
	P METAL	Ultra thin metal

: Optimal : Suitable

I would like to purchase EXEDY products, but can I purchase it directly?: We are sorry but the EXEDY products are sold only through our dealers, and we do not sell our products directly.
Please contact the dealers close to you.

Why is the diaphragm spring matte finish for some of the EXEDY multi plate clutches?: This is because there is a special coating on the surface of the diaphragm spring.
Some of the twin clutches are using two diaphragm springs, one on top of the other.
Operation load (release load = force on the pedal) becomes greater due to the sliding resistance occurring when the two diaphragm springs rub each other during the operation of the diaphragm spring.
EXEDY has reduced the force on the pedal by adopting this special coating.

There is a ring shaped parts between the cover assembly and the pressure plate of the EXEDY multi plate clutches, but what does this do?: This is a part called “pivot ring”, and it will enhance the clutch engaging performance.
In the normal clutches, clutch engaging performance is enhanced by placing a wavy cushion plate between the facings, but this method cannot be used for the metal and carbon materials, so the “pivot ring” is reducing the shock when the clutch is engaged as a disc spring, in turn enhancing the clutch engaging performance.

Do I need to apply grease to the spline of the disc?

Yes, it is required.
However, depending on the method of application and the amount, applied grease may disperse, causing judder and bad disengagement.

Precautions

(1) Apply grease evenly to the spline tooth surface of both the main shaft side and the disc side using a brush or similar.
(2) After the application, insert the disc into the main shaft, and slide it to see if it will move smoothly.
(3) Wipe off the grease straying out from the disc and the main shaft using a rag or something.

<Caution>
Be careful not to deposit any grease or any other oil on the friction surface (flywheel, P PLATE, IM PLATE, disc). It may cause judder, slip, etc.

What is the tightening torque of the cover bolts?: Tighten the hexagon headed cover bolts of the HYPER SERIES (M8 hexagon bolt) with the torque of 27-33 Nm.
For the SINGLE SPORTS SERIES, tighten them by referring to the maintenance manuals issued by the automobile manufacturers.

Other

Is the “EXEDY Clutch” the same thing as the “Daikin Clutch”?: Yes. The company name was changed from “Daikin Mfg. Co., Ltd.” to “EXEDY Corporation” in August 1995.
At the same time, our brand name was changed from “Daikin Clutch” to “EXEDY Clutch”.