"This entry is part of a Special Series on my S65 lightweight flywheel experiments as a part of my Ultimate Response Blueprint.

I’ve always been weary of lightweight flywheels and was anxious to installing this considering the labor involved.

In this entry, I document the installation and my notes along the way.

It isn't that hard - 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 intensity.

The exhaust, driveshaft and transmission are all coming off. It's something you do usually while you're in there with other maintenance and upgrades to the transmission, driveshaft, etc.  

Getting the DCT transmission off this car is not an easy task. It's much heavier than the MT transmission - you absolutely need a proper transmission jack.

We didn't have one. 

The dexterity.

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 of these hoses were awaiting refitting. We had to replace one time use O rings as well. 

The anxiety.

Playing with anything bolted to a crankshaft spinning to 8,600 RPM is an anxious experience for first timers. 

This is where you can most costly mistakes. 

Mission critical steps. 

Starter Alignment

Both the OEM and TTV flywheel have a bolt holt with a different shape others: this is your engine to starter alignment. Mess this up and the S65 won't crank once you have everything bolted back together. 

The TTV's shape is slightly less pronounced than the OEM flywheel shown below - it's still visible once you pay attention. 

Take it from me, you don't want to have to do it twice (oups!).

The underside - this side goes against the crank.

The mission critical bolts.

You can't reuse the OEM bolts are they are encased in the flywheel. You need to get 9x new BMW flywheel bolts (11227520706). I can't emphasize this enough: triple check the bolts you use. Use the wrong bolts can lead to catastrophic engine failure.

The updated version of the S65 DCT flywheel comes with TTV Racing specific bolts they provide. 

They need to be dipped!

BMW TiS requires the bolts be dipped in engine oil before being torque. This is technique to allow higher efficiency during the torquing sequence. 

Precision is key here. You dip them in engine oil while bolting them in, and you torque them criss-cross.

You don't use these bolts anymore for the DCT, you do for the 6spd. These are N55/S55 crank bolts. 

 

No tune needed! 

This sounds alien - but it's reality. Bolt it up, start her up, and be on your way. 

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.