Drivetrain:
Many of the key components of the drive train have been upgraded to help deliver more torque to the rear wheels.  A lightweight flywheel can save 15-20 lbs off the stock flywheel but most importantly it significantly reduces the rotational mass the engine has to overcome to deliver torque to the rear wheels.  The lightweight flywheel makes it easier to match revs and shift quickly as the engine does not have to labor to turn a heavy flywheel up to speed.  The transmission brace keeps the transmission firmly in place to reduce power loss from lateral shifting.  It also aids in shifting for the driver as the gear positions are where they are expected to be.  This is even more important with the installation of a short shifter which has a smaller shift pattern.  The stock differential in a 95 M3 is a short diff with a 3.15:1 ratio and 25% lock.  Upgrading this to a 3.46:1 with a 40% lock translates into more torque at the rear wheels and the additional lockup means more power to the wheels before slip is allowed.  The larger finned diff cover carries more diff fluid and the fins help keep it cool.  The diff gearing takes a beating it is where power is transferred 90 degrees from the drive shaft to the rear wheel half shafts.  There is a lot of pressure, wear and heat generated in the differential under race conditions.
Pictures:

Parts:
	Lightweight Flywheel Description: 14lb flywheel Benefits: A lighter flywheel reduces the rotational mass the engine turn under acceleration.  A lighter flywheel allows more torque to be transferred to the rear wheels.  The lighter flywheel also allows the driver to quickly match rev's when down shifting.
	Transmission Brace Description: Transmission support Benefits: This sturdy transmission brace combined with firm race bushings prevents the transmission from shifting
	UUC Short Shifter Description: High performance shifter Benefits: The shorter shifter decreases the shifter travel necessary to change gears.  The shifter has a compound bend in the shaft so that the shifter position and pattern is in the correct position.  This is the original design and one of the first that began what is now a common upgrade for most BMWs street or track.
	Differential Cover Description: Large capacity finned differential cover Benefits: The fins and larger capacity help cool the differential fluid increasing life and reliability. Increased lockup from friction plates can increase the heat generated by the differential.  The larger finned cover help dissipate this increased heat.
	3.46:1 Differential with 40% Lockup Description: Differential with different gearing Benefits: Increasing the ratio of the differential increases the torque to the rear wheels.  The increased lockup increases the duration through which torque is delivered to both rear wheels before power is diverted to wheel with most traction.

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