E39 M5 Lightweight Flywheel

The Lightweight Flywheel fits within that concept by freeing up horsepower, allowing much easier throttle blips for manual guys, and allowing faster pick up in gear. Lightweight Flywheels will also induce slight noise and chatter at idle, something to keep in mind for mostly daily driven vehicles.

I have been hunting the European market for a lightweight flywheel and found many Nurb track tools sporting the TTV Industrial flywheel setups.  These flywheels are commonly used in S52 Motorsport applications with drastically increased power.

About TTV Racing

TTV Racing is part of TTV Industrial ltd which is a family run business located in the East of England. TTV has been precision engineering for over 30 years, designing and manufacturing automotive parts for original equipment & motorsport, club racer to world championship. 

The flywheels offered for BMW M cars use the same material, the same machines and same tooling TTV uses to manufacture products for Motorsport teams worldwide. 

Why TTV uses Forged Billet High Carbon Steel over Aluminium 

Let's get the obvious of the way: aluminium is a cheap and quick to machine material which means the flywheels are cheap to make.

There are no other technical and engineering benefits to running an aluminium flywheel over steel.

Aluminium is 1/3^rd the weight of steel but its also 1/3^rd the strength, as such, you need 3 times as much of it.

Having 2 different materials bolted together is not ideal when the parts warm up and start to expand as the expansion rates are different putting components under stress, this is more important when you consider the starter ring gear is steel. Failure here could be catastrophic.

Motorsport teams will not use aluminium flywheels due to their inherent reliability risks, the steel used for the friction faces tend to be of lower quality and wear out quickly when used with modern drivetrain friction materials.