Mantic: Installation Instructions For Mantic Clutch Kits – Racing Applications Part 2

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Flywheel Design Considerations:

When installing a Mantic kit that is not a “Direct Fit Kit” i.e. it does not come with a purpose fit flywheel, it is important that the Flywheel being made conforms to the dimensions in the sketch below as a minimum to ensure correct fitment.

Fitting to an existing 7.25” / 5.5” flywheel: (7000, 5000 series)

(It is essential that the working surface of the flywheel be ground, or the flywheel replaced if cracks are present.)

When using an existing 7.25” or 5.5” flywheel, the PCD (Pitched Circle Diameter) of the Mantic 7000 / 5000 clutch is the same as used currently by most clutch companies.
When using these flywheels it is possible to bolt the clutch to the flywheel from the clutch (out) side into the existing threaded holes.
Ensure that the bolts are the correct length not to foul, that they are #Grade 8 (minimum) tensile strength, and the supplied washers are used under the head of each bolt. Tension the clutch to 33Nm.
The only modification needed in this instance is to ensure that there is a -1.5mm deep groove cut into the flat surface of the clutch working area to locate the drive blocks. (See diagram below.) This groove is essential for the operation of the clutch to ensure that the height of the clutch is to correct specification.
Check and adjust pedal throw / bearing travel as specified below. A pedal stop may need to be fitted.

Fitting to an OEM or aftermarket flywheel: (9000, 7000, 5000 series)

Re drill the flywheel with the correct mounting bolt pattern and PCD (Pitched Circle Diameter). This should be done by a specialist engineer to ensure absolute accuracy.
Machine a -1.5mm deep groove on the working surface of the flywheel to locate the clutch drive blocks as per the dimensions in the diagram below. This groove is essential for the operation of the clutch to ensure that the heights of the clutch are to correct specification.
If mounting the clutch with bolts coming from the rear of the flywheel, a groove must be machined into the rear of the flywheel to locate the bolt heads. (see diagram in Release Bearing Installation, next post).
Ensure that the bolts are the correct length not to foul, that they are #Grade 8 (minimum) tensile strength, and the supplied washers are used under the nut of each bolt. Tension the bolts to 33Nm.
If mounting the clutch with bolts coming from the front of the flywheel, it is vital that there be sufficient material for the threads to ensure the structural integrity of the flywheel.
Ensure that there is a -1.5mm deep groove cut into the flat surface of the clutch working area as per the diagram below. This groove is essential for the operation of the clutch to ensure that the heights of the clutch are to correct specification.
Check and adjust pedal throw / bearing travel as specified below. A pedal stop may need to be fitted.

Clutch height / release load Specifications

Clutch type	Release Load (Max)	Diaphragm finger height (compressed)	Overall Height	Cover to Flywheel bolt torque
	lbs/kg	in/mm	in/mm	lb.ft / Nm
9000 2 disc	419lbs/190kg	1.87in / 47.5mm	2.44in / 62.0mm	24 ft lb / 33Nm
7000 3 disc	595lbs/270kg	1.46in / 37.0mm	2.09in / 53.0mm	24 ft lb / 33Nm
7000 2 disc	595lbs/270kg	1.14in / 29.0mm	1.77in / 45.0mm	24 ft lb / 33Nm
5000 3 disc	660lbs/300kg	1.57in / 40.0mm	2.19in / 55.5mm	24 ft lb / 33Nm
5000 2 disc	660lbs/300kg	1.15in / 29.1mm	1.85in / 47mm	24 ft lb / 33Nm
Height is measured from flywheel drive block mounting surface. Direct fit to most 5.5in / 7.25in flywheel bolt patterns. F/W must be modified Cover to flywheel bolts must be minimum grade #8. M8 x 1.25 or 5/16 UNF must be used. Refer to fitting instructions for custom F/W specifications

Bearing Contact Diameter and Travel Required

Mantic Kit type	Contact Face Type	Bearing Travel Max	Bearing Travel Min	Bearing Contact Diameter Max	Bearing Contact Diameter Min
9000 Racing Series (Cushioned discs)	Flat	11.5mm	11.0mm	68mm	47mm
9000 Racing Series (Non Cushioned discs)	Flat	7mm	5mm	68mm	47mm
7000 Series	Radial	7mm	5mm	50mm	46mm
5000 Series	Radial	7mm	5mm	42mm	38mm

NOTE: When modifying an existing flywheel to the above specifications, it is critical that there be sufficient strength remaining to maintain the structural integrity of the flywheel. Mantic accepts no responsibility for the subsequent failure of such a modified flywheel. It is strongly recommended that cast iron flywheels are not used.

It is strongly recommended that cast iron flywheels are not used.