Clutch Stages and Compatibility

In the process of examining various reluctor teeth for use in rpm measurement, it was remembered that the Aluminum flywheel located within the transmission, has a collar of iron teeth that previously were used to engage the starter of the ICE.  These teeth might provide a signal if a sensor could be properly positioned both through the adapter plate and adjacent to the metal teeth of the flywheel. 

The Stage 2 clutch for this 1992 BMW 325i EV conversion was previously reported in this May 3, 2013. 
(  http://evbimmer325i.blogspot.com/2012/05/theracing-aluminum-flywheel-blue-left.html ).
Some online research was undertaken to learn more about what the clutch "Stages" represent, and what characteristics might be expected from each of them.  For this blog entry data was taken from the eBay products that are offered by F1 Racing (California) on eBay.

Definition of Clutch Stages (as described by VITEK Performance)

Stage 1 - Offers approximately 25% increase in strength and durability over your original equipment clutch while maintaining the same smooth driving characteristics. It comes with a high clamp pressure plate, steel-backed woven organic disk, bearings, and tool.

Stage 2 - This clutch has a dual sprung disc with full face Kevlar®. It offers the optimum street durability with smooth engagement. The characteristics are more of a street/daily driver feel however, this clutch can handle greater strain and will last far longer than the OE Clutch. It comes with a high clamp pressure plate segmented chatter-free Kevlar disc, bearings and installation tool.

Stage 3 - Comes with a dual sprung carbonic disc. It allows for aggressive street and track driving while at the same time still works well for daily driving. It is more aggressive than a full-face disc and will easily handle Turbo/NOS etc. Sharp but smooth engagement with light pedal. It is our best selling clutch because it offers the best of both worlds. It comes with a high-clamp pressure plate, 3-piece disc with carbon or ceramic material, bearings, and the installation tool.

Stage 4 - This clutch has a 6 puck Un-sprung Disc. It is not designed for your daily driver car. When using an un-sprung clutch, you will probably experience moderate chatter. You should be prepared to hear your passenger complaining about the whiplash he or she will get every time you pull away from a light. While it will handle extreme aggressiveness, it is either engaged or disengaged with no ability to ease into the clutch. Its optimum use is designed for rally racing.

Stage 5 - This clutch is for racing only. It is of a 3 puck ceramic design and offers optimum performance for the drag strip.

Stage 1

Condition:	New	Manufacturer Part Number:	F04118R0 F04117FA
Warranty:	Yes	Interchange Part Number:	03-011 KF649-01 03-030 K70206-01 K70238-01 195321
Brand:	FX Racing	Surface Finish:	HD ORGANIC; 6061 BILLET ALUMINUM
Part Brand:	FX Racing

FX Racing Stage 1 clutch kit is an upgrade heavy-duty clutch set up for those who seeks streetable high performance clutch. It is a direct factory replacement parts thus no modifications are needed. The clutch kit includes only the highest grade components and it's ready for hot action on street and track. The premium organic friction material for high heat tolerance, quick recovery, good friction and long life. The heavy-duty solid center unit boasts heat treated hub and retainer rivets for the maximum power and durability. The FX Racing pressure plate features special single diaphragm design to increase clamp load. It features induction hardened diaphragm, CNC machined castings, stronger drive straps and rivets. FX Racing pressure plate provides smooth and precise feel with easy modulation. All FX Racing pressure plate is load tested on a special testing tool for quality assurance.

FX Racing Aluminum Flywheels are made using the highest quality, most modern materials available. The flywheel itself is made from 6061 T6 billet aluminum. It is CNC machined at a constant surface speed for durability and finish. The friction surface is made from high carbon alloy steel. It is incredibly durable allowing the user to use just about any clutch disc material available from organic to Kevlar and even sintered iron. The friction plate can be machined or replaced as needed. The mass at the center of the flywheel is retained for strength, but the mass at the outside is eliminated for optimum performance.

• Ultra light and weighs only 10.4 lbs
• Meets or exceeds SFI 1.1 specification
• Course ground surface to maintain coefficient of friction
• Stepped pin to maintain plate balance and placement
• Tig-welded safety tab to eliminate ring gear separation
• Heilicoil bolt holes to insure proper torque value and eliminate thread damage
• A set of brand new 8 ea. flywheel bolts are included
• NOTE: Replacement of dual mass flywheel may cause added gear noise

This complete clutch kit and flywheel package includes:
• FX Racing Lightweight Aluminum Racing Flywheel (10.4 lbs)
• FX Racing Heavy-Duty Pressure Plate
• FX Racing Stage 1 HD Full Face Rigid Disc (240mm, 10 spline)
• Release Bearing, Pilot Bearing, Alignment Tool, and Installation Guide

Horsepower Rating: 342 HP / Torque Capacity: 315 ft/lbs

Stage 2

Condition:	New	Manufacturer Part Number:	F04118R1 F04117FA
Warranty:	Yes	Interchange Part Number:	03-011 KF649-01 03-030 K70206-01 K70238-01 195321
Brand:	FX Racing	Surface Finish:	CARBON KEVLAR; 6061 BILLET ALUMINUM
Part Brand:	FX Racing

FX Racing Stage 2 clutch kit is a step up from our Stage 1 clutch kit. This is a versatile set up for the street and on the track. It provides a smooth engagement yet it can holds 50%+ more power over stock clutches. This is a direct factory replacement clutch kit thus no modifications are needed and the clutch kit includes only the highest grade components from world's leading high performance clutch manufacturer. The Carbonized Kevlar friction material is used on all Stage 2 clutch kit to have higher burst strength and heat tolerance. The heavy-duty sprung center with heat treated springs and retainer rivets to increase strength and reliability. The FX Racing pressure plate features special single diaphragm design to increase clamp load. It features induction hardened diaphragm, CNC machined castings, stronger drive straps and rivets. FX Racing pressure plate provides smooth and precise feel with easy modulation. All FX Racing pressure plate is load tested on a special testing tool for quality assurance.

FX Racing Aluminum Flywheels are made using the highest quality, most modern materials available. The flywheel itself is made from 6061 T6 billet aluminum. It is CNC machined at a constant surface speed for durability and finish. The friction surface is made from high carbon alloy steel. It is incredibly durable allowing the user to use just about any clutch disc material available from organic to Kevlar and even sintered iron. The friction plate can be machined or replaced as needed. The mass at the center of the flywheel is retained for strength, but the mass at the outside is eliminated for optimum performance.

• Ultra light and weighs only 10.4 lbs
• Meets or exceeds SFI 1.1 specification
• Course ground surface to maintain coefficient of friction
• Stepped pin to maintain plate balance and placement
• Tig-welded safety tab to eliminate ring gear separation
• Heilicoil bolt holes to insure proper torque value and eliminate thread damage
• A set of brand new 8 ea. flywheel bolts are included
• NOTE: Replacement of dual mass flywheel may cause added gear noise

This complete clutch kit and flywheel package includes:
• FX Racing 6061 T6 Lightweight Aluminum Racing Flywheel (10.4 lbs)
• FX Racing Heavy-Duty Pressure Plate
• FX Racing Stage 2 Steel Back Carbon Kevlar Sprung Disc (9-1/2" , 10 spline)
• Release Bearing, Pilot Bearing, Alignment Tool, and Installation Guide

Horsepower Rating: 403 HP / Torque Capacity: 342 ft/lbs

 Stage 3

Condition:	New	Manufacturer Part Number:	F04118R3 F04117FA
Warranty:	Yes	Interchange Part Number:	03-011 KF649-01 03-030 K70206-01 K70238-01 195321
Brand:	FX Racing	Surface Finish:	6 PUCK SPRUNG COPPER CERAMIC MIBA BILLET ALUMINUM
Part Brand:	FX Racing

FX Racing Stage 3 clutch kit is a direct factory replacement clutch kit and it's designed for those who seek the ultimate in clutch performance and reliability. FX Racing clutch kit includes only the highest grade clutch components from the world's leading racing clutch manufacturers. The 6-puck copper ceramic (also known as MIBA) disc features 12 high-coefficient friction pads that are resistant to slippage and ensures long lasting life. The heavy-duty sprung center unit boasts heat treated springs and retainer rivets for the maximum power and durability. The FX Racing pressure plate features special single diaphragm design to increase clamp load. It features induction hardened diaphragm, CNC machined castings, stronger drive straps and rivets. FX Racing pressure plate provides smooth and precise feel with easy modulation. All FX Racing pressure plate is load tested on a special testing tool for quality assurance.

FX Racing Aluminum Flywheels are made using the highest quality, most modern materials available. The flywheel itself is made from 6061 T6 billet aluminum. It is CNC machined at a constant surface speed for durability and finish. The friction surface is made from high carbon alloy steel. It is incredibly durable allowing the user to use just about any clutch disc material available from organic to Kevlar and even sintered iron. The friction plate can be machined or replaced as needed. The mass at the center of the flywheel is retained for strength, but the mass at the outside is eliminated for optimum performance.

• Ultra light and weighs only 10.4 lbs
• Meets or exceeds SFI 1.1 specification
• Course ground surface to maintain coefficient of friction
• Stepped pin to maintain plate balance and placement
• Tig-welded safety tab to eliminate ring gear separation
• Heilicoil bolt holes to insure proper torque value and eliminate thread damage
• A set of brand new 8 ea. flywheel bolts are included
• NOTE: Replacement of dual mass flywheel may cause added gear noise

This complete clutch kit and flywheel package includes:
• FX Racing Lightweight Aluminum Racing Flywheel
• FX Racing Heavy-Duty Pressure Plate
• FX Racing Stage 3 'MIBA' 6-Puck Copper Ceramic Sprung Disc (9-1/2" , 10 spline)
• Release Bearing, Pilot Bearing, Alignment Tool, and Installation Guide

Horsepower Rating: 487 HP / Torque Capacity: 435 ft/lbs

Stage 4

Condition:	New	Manufacturer Part Number:	F04118R4 F04117FA
Warranty:	Yes	Interchange Part Number:	03-011 KF649-01 03-030 K70206-01 K70238-01 195321
Brand:	FX Racing	Surface Finish:	6 PUCK RIGID COPPER CERAMIC MIBA BILLET ALUMINUM
Part Brand:	FX Racing

FX Racing Stage 4 clutch kit is a direct factory replacement clutch kit and it's designed for those who seek the ultimate in clutch performance and reliability. FX Racing clutch kit includes only the highest grade clutch components from the world's leading racing clutch manufacturers. The 6-puck copper ceramic (also known as MIBA) disc features 12 high-coefficient friction pads that are resistant to slippage and ensures long lasting life. The heavy-duty solid spline center unit boasts heat treated chromoly for the maximum power and durability. The FX Racing pressure plate features special single diaphragm design to increase clamp load. It features induction hardened diaphragm, CNC machined castings, stronger drive straps and rivets. FX Racing pressure plate provides smooth and precise feel with easy modulation. All FX Racing pressure plate is load tested on a special testing tool for quality assurance.

FX Racing Aluminum Flywheels are made using the highest quality, most modern materials available. The flywheel itself is made from 6061 T6 billet aluminum. It is CNC machined at a constant surface speed for durability and finish. The friction surface is made from high carbon alloy steel. It is incredibly durable allowing the user to use just about any clutch disc material available from organic to Kevlar and even sintered iron. The friction plate can be machined or replaced as needed. The mass at the center of the flywheel is retained for strength, but the mass at the outside is eliminated for optimum performance.

• Ultra light and weighs only 10.4 lbs
• Meets or exceeds SFI 1.1 specification
• Course ground surface to maintain coefficient of friction
• Stepped pin to maintain plate balance and placement
• Tig-welded safety tab to eliminate ring gear separation
• Heilicoil bolt holes to insure proper torque value and eliminate thread damage
• A set of brand new 8 ea. flywheel bolts are included
• NOTE: Replacement of dual mass flywheel may cause added gear noise

This complete clutch kit and flywheel package includes:
• FX Racing 6061 T6 Aluminum Lightweight Flywheel (10.4 lbs)
• FX Racing Heavy-Duty Pressure Plate
• FX Racing Stage 4 'MIBA' 6-Puck Copper Ceramic Rigid Disc (9-1/2" , 10 spline)
• Release Bearing, Pilot Bearing, Alignment Tool, and Installation Guide

Horsepower Rating: 487 HP / Torque Capacity: 435 ft/lbs

 

Clutch Compatibility 

 

1991	525i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1992	525i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1992	325is	Base Coupe 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1992	325i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1993	525i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1993	325is	Base Coupe 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1993	325i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1994	525i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1994	325is	Base Coupe 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1994	325i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1994	325i	Base Convertible 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1995	M3	Lightweight Coupe 2-Door	3.0L 2990CC l6 GAS DOHC Naturally Aspirated
1995	M3	Base Coupe 2-Door	3.0L 2990CC l6 GAS DOHC Naturally Aspirated
1995	525i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1995	325is	Base Coupe 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1995	325i	Base Sedan 4-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1995	325i	Base Convertible 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1996	M3	Base Coupe 2-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1996	328is	Base Coupe 2-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1996	328i	Base Sedan 4-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1996	328i	Base Convertible 2-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1997	Z3	Roadster	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1997	M3	Base Sedan 4-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1997	M3	Base Coupe 2-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1997	528i	Base Sedan 4-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1997	328is	Base Coupe 2-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1997	328i	Base Sedan 4-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1997	328i	Base Convertible 2-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1998	Z3	Roadster	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1998	Z3	M Roadster	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1998	M3	Base Sedan 4-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1998	M3	Base Coupe 2-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1998	M3	Base Convertible 2-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1998	528i	Base Sedan 4-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1998	328is	Base Coupe 2-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1998	328i	Base Sedan 4-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1998	328i	Base Convertible 2-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1998	323is	Base Coupe 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1998	323i	Base Convertible 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1999	Z3	M Roadster	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1999	Z3	M Coupe 2-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1999	M3	Base Coupe 2-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1999	M3	Base Convertible 2-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
1999	328is	Base Coupe 2-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1999	328i	Base Convertible 2-Door	2.8L 2793CC l6 GAS DOHC Naturally Aspirated
1999	323is	Base Coupe 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
1999	323i	Base Convertible 2-Door	2.5L 2494CC 152Cu. In. l6 GAS DOHC Naturally Aspirated
2000	Z3	M Roadster	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
2000	Z3	M Coupe 2-Door	3.2L 3152CC l6 GAS DOHC Naturally Aspirated
2001	Z3	M Roadster	3.2L 3246CC l6 GAS DOHC Naturally Aspirated
2001	Z3	M Coupe 2-Door	3.2L 3246CC l6 GAS DOHC Naturally Aspirated
2002	Z3	M Roadster	3.2L 3246CC l6 GAS DOHC Naturally Aspirated
2002	Z3	M Coupe 2-Door	3.2L 3246CC l6 GAS DOHC Naturally Aspirated

 

 

WIndshield Replacement 1.0

The 1992 BMW 325i has two windshield related defects that require attention.  The most prominent is a central star crack that appeared during careless handling during the move to the garage, and the second is a rust defect in the sheet metal at the location where the center windshield wiper mechanism is mounted. 

 

 

 

Picture DSC02017 of the cracked windshield caused by blunt force trauma during the move.

 

 

Picture DSC02014 of the damaged center windshield mounting point.  Years of outside storage likely contributed to this rust.  The heat that will be generated during the welding repair will likely cause the adhesive to melt and interfere with the repair and the glass itself to shatter.

 

Local windshield replacement companies indicated that they will travel to the car and install an aftermarket windshield for between $100 and $150.  This is not a significant expenditure but it was wondered what was involved with the process of windshield replacement. 

Some interesting videos of the replacement process were found at:

https://www.youtube.com/watch?v=in6o-tmnPyw

https://www.youtube.com/watch?v=JdPL4bLbDUc

If a replacement windshield is provided, then the on site installation is about $50-$60.  Various BMWs can be found at the salvage yard and the glass is priced at $10.  The question was, which BMW models might provide a suitable donor glass. 

Contact with Patrick BMW indicated that the 1992 BMW 325i could use either part number 51311977217 or 51311977216, depending upon the style of shade band desired.

The following list of possible donor vehicles was compiled after editing information that was found on realoem.com .

Part 51311977217 (Green windscreen, green shade band) was found on the following vehicles:

E36 318i Sedan, M44, USA, AUTO (CC03)  :
E36 318i Sedan, M42, USA, AUTO (CA63) :
E36 318i Sedan, M42, USA, AUTO (CC83) :
E36 318i Sedan, M44, USA, AUTO (CD83) :
E36 318i Sedan, M44, USA, MANUAL (CD73) :
E36 318i Sedan, M44, USA, MANUAL (CC93) :
E36 318i Sedan, M42, USA, MANUAL (CA53) :
E36 318i Sedan, M42, USA, MANUAL (CC73) :
E36 320i Sedan, M50, USA, AUTO (CB23) :
E36 320i Sedan, M50, USA, MANUAL (CB13) :
E36 325i Sedan, M50, USA, AUTO (CB43) :
E36 325i Sedan, M50, USA, MANUAL (CB33) :  
E36 328i Sedan, M52, USA, AUTO (CD23) :  
E36 328i Sedan, M52, USA, AUTO (CD43) :  
E36 328i Sedan, M52, USA, MANUAL (CD13) :  
E36 328i Sedan, M52, USA, MANUAL (CD33) :  
E36 M3 Sedan, S52, USA, AUTO (CD03) :  
E36 M3 Sedan, S52, USA, MANUAL (CD93) :  
E36 318ti Compact, M44, USA, AUTO (CG83) :  
E36 318ti Compact, M42, USA, AUTO (CG63) :  
E36 318ti Compact, M42, USA, MANUAL (CG53) :  
E36 318ti Compact, M44, USA, MANUAL (CG73) :  
 
Part 51311977216 (Windshield, clear with anti-glare strip) was found on the following vehicles:

E36 318ti Compact, M42, USA, AUTO (CG63) :  
E36 318ti Compact, M44, USA, AUTO (CG83) :  
E36 318ti Compact, M42, USA, MANUAL (CG53) :  
E36 318ti Compact, M44, USA, MANUAL (CG73) :  

 

Reluctors for RPM Measurement

 

A reluctor sensor measures the ability of magnetic fields to pass through adjacent structures and it measures the changes in the magnetic field lines.  The presence of metal allows the field lines to readily pass, while nonmagnetic materials impede the passage.  Aluminum with embedded steel set screws or a sprocket style all steel reluctor can provide the required environment for a reluctor sensor to measure changes in magnetic fields.

 

One commercially available reluctor ring (Picture DSC01888) is a 1.50 inch diameter and 9/16 inch thick Aluminum ring with four symmetrical steel set screws.  The heads of the 5/16-8 set screws are 0.25 inch across and when tightened are nearly flush with the ring surface.  If only two set screws are used, then a two pulse per revolution signal can be produced.  A companion reluctor sensor can be mounted adjacent to the motor or affixed to the face of the Warp motor (Picture DSC02023 below).

 

 

 

Picture DSC01888 of an Aluminum ring with four set screws.  The heads of the screws are nearly flush with the ring surface when installed.  When used with a companion electrical sensor, the RPM of a rotating shaft can be measured.

 

 

 Picture DSC02023 showing the mounting plate that positions the sensor adjacent to the reluctor ring.  

 

 

 

Picture DSC02024 showing a close up of the sensor and Aluminum ring.  For clarity the picture shows a large gap between the sensor tip and the steel set screws that are threaded into the Aluminum ring.  When operational, the gap is reduced until almost eliminated to enhance both the magnitude and the quality of the signal.  

 

Drawing 20141010 by David of DMF Consulting of a first generations square tooth reluctor.  The final outline of the cut was the composite of three separate square end mill cuts.  

 

 

 

 

Picture DSC01840 face view of the steel reluctor prior to mounting on the Warp 11 0.875 shaft.

 

 

 

Picture DSC01843 edge view showing the 0.50 inch thick piece with a 10/24 set screw.

 

 

 

 

 

Picture DSC01847 of the installed first generation all steel reluctor along with the sensor and mounting bracket.

 

 

An alternative more elegant second generation reluctor was machined by David starting with 2 inch diameter steel rod stock.  After a 0.5 inch thick disk was cut from rod stock, it was bored out to either a 0.875" or 1.125" center hole, and then it was machined to produce a six tooth sprocket. 

 

Drawing by David of the second generation reluctor that can be used with the 1.125" shaft found on current Warp-11 motors.  It was produced from a 0.5 inch thick section of rod stock using a 0.5' diameter mill bit.

 

 

  

Picture DMF-DSC0285 showing David's setup on his mill using a Collet Indexer and a 0.5" Ball-End Four Flute Carbide End Mill (McMaster part 88805A45).  The center of the steel stock was held with an Expanding-End Mandrel (McMaster part 2779A22).  The final outline of the cut was identical to the outline of the mill bit

 

 

 

Picture of a Collet Indexer of the style that was used to prepare the  reluctors shown in picture DMF-DSC0285 above and DMF-DSC01289 below.

 

 

 

 

Picture DMF-DSC01289 of the final 6 tooth reluctors prepared by David using a mill bit and a 2" diameter x 0.5" thick (McMaster Carr cat # 7786T12 , $3.03) steel disk.  The left unit was prepared for a 0.875" shaft (for an older model Warp-11 manufactured prior to 7/1/2012) , and the right unit was prepared with a 1.125" shaft opening (for Warp-11 manufactured after 7/1/2012).  The set screws were 10-32 x 3/16 for the 0.875 shaft and 10-32 x 5/16 for the 1.125 shaft on the right.

 

Alternative use of the BMW Harmonic Damper

 

Interestingly, it is possible to create a reluctor using the original BMW OEM harmonic damper that originally has 58 teeth and two missing teeth.  If a rotary table is used on a mill to symmetrically remove patterns of the teeth, it is possible to create a reluctor with 20 or 15 or 12 or 10 or 6 or 5 or 4 or 3 or 2 or 1 remaining tooth.  

 

 

 

Picture of the original BMW OEM harmonic damper prior to modification.

 

 

 

 

Picture showing the appearance of the BMW OEM harmonic damper after removing pairs of two teeth and alternating with 1 remaining tooth followed by 2 missing teeth, etc.   In this example the modified harmonic damper has a total of 20 teeth.  If it is intended to use the pulley that is integral to the harmonic damper, then this modification would allow RPM measurement without the need to purchase additional hardware.