IMPORTANT FACT READ THIS FIRST!
Towards the end of e30 production there was a significant change to the ring gear tooth profile ............ WE HAVE BOTH TYPES! ............
Different countries got the upgrade at different times but generally around 1988-89. Also many cars have since been fitted the wrong replacement starters. (cheap aftermarket starters are generally late model version) Using the wrong starter causes a lot of very harsh noise, excessive tooth wear and eventual stripping of the ring gear teeth. The only fail safe way to tell the difference and that is to count the teeth.
Early version FW has 137t
Late version FW has 116t.
This change is only relevant to the starter!!... ALL other fitment and clutch details are exactly the same, so please choose the correct one in the options below
DONT WORRY if you have the wrong one, changing to the correct starter will fix the issue... (easier than changing the FW)
These flywheels are a direct replacement/ standard fitment to all M20 engines from 1977 to 1992 however they will not work with the first 325e engines (only in production for 1-2 years around 1985-86) it does not have the extra tooth for the the bell-housing mounted crank sensors.
Made from High tensile Chrome-molly steel these flywheels are both light and very strong.
Weighing only 3.4Kg (7.4Lb) they will greatly increase the response and acceleration of any vehicle
All m20 engines have the same clutch fitment... However it must be from SINGLE MASS Flywheel.
There are different part numbers for different models but they will ALL fit this FW providing they are SMF version.
Some OEM part numbers for Clutch kits
21211223119 or 21211223102
Sachs sport pressure plate 883082999618
It is recommended to check the slave cylinder piston travel and make sure it sits at about 60-70% compressed when installed.
It is a common perception that a large flywheel is used to increase the torque of and engine and with a light flywheel an engine will have less torque but this is NOT the case! Heavy flywheels are used only to ease the smooth engagement of the clutch so Grandma can take off without stalling the engine and thats it! maybe improve idle quality a little also. Once the car is rolling and the clutch is fully engaged the flywheel becomes completely unnecessary because the entire vehicle and its driveline becomes the flywheel storing huge amounts of momentum. Any additional weight particularly on the crank shaft because this spins at higher speeds only reduces the vehicles capability to accelerate briskly. So if Grandma isnt going to drive your car and you don't mind having to use a little more finesse with the clutch pedal to take off from the lights then you will enjoy all the benefits of having a snappy responsive engine with much improved acceleration that comes with installing a light flywheel, even if its only a daily driven road car! We have many happy customers driving around on these flywheels just find and ask someone and they will be happy to report that drivability is not compromised at all, but the improved response and acceleration is very pronounced!