"In this entry, I document the installation and my notes along the way. It isn't complex - but you need to know what you're doing. "
- Matt

This is not a DIY for most.

There are a couple reasons I make this claim.

The exhaust, driveshaft and transmission need to be removed off. As a result, the lightweight flywheel is an upgrade usually performed with other maintenance and upgrades to the transmission, driveshaft, etc.  

Getting the DCT transmission off this car is not an easy task; it weighs +/- 150 lbs. It's +/- 40 lbs heavier than the manual transmission. You absolutely need a proper transmission jack. 

For professionals, expected labor is 6 to 8 hours. 

The DCT has extra coolant lines and peculiar fittings that require hands-on knowledge, otherwise you're in for a long, rough, and risky experience. All the hoses seen below were awaiting refitting. We had to replace all one time use O rings as well. 

Mission critical steps. 

Starter Alignment

Both the OEM and lightweight flywheel have a bolt holt with a different shape others: this is your engine to starter alignment. 

The lightweight starter alignment hole's shape is slightly less pronounced than the OEM flywheel shown below - it's still visible once you pay attention. If the bolt hole is not aligned, the S65 won't crank.

Bolts. 

You cannot reuse the OEM bolts are they are encased in the original dual mass flywheel. They can be seen below on the engine side of the flywheel. 

BMW requires their extended Torx 60 tool to access the bolts for proper torquing sequences. This tool is not required for the lightweight flywheel.  

The updated version of the S65 DCT lightweight flywheel is now packaged with new flywheel to crankshaft bolts with the correct ratings.

Torque specs.

BMW TIS requires the bolts be dipped in engine oil before being torqued to 105NM. The wet torque reduces friction and improves the consistency of the clamping force. Be sure to follow the torque sequence as per the TIS. 

No tune needed. 

Bolt it up, start her up, and be on your way. I do personally run an increased idle RPM to 900 to improve drivability in cold start conditions. You can learn more here.

No break-in period.

The flywheel itself doesn't have a break-in period per say. You can rev it to the moon. The sound will have a break-in period: it will evolve over time as you start using the car. 

Up next: we bolt everything back, and we go for drive.

What is worth it?

We'll have a chat, and record some clips.