Help Choosing a Clutch for S54 + ZF 320Z Swap

[R3VM3UP]

Quick update, I drove the car with this setup for the first time recently and so far everything seems to work great. Here's the complete setup:
S54
E46 M3 OE flywheel
E36 M3 Clutch
E46 M3 OE pressure plate
E36 M3 throw out bearing
ZF 5spd from E36 328i
E30 318is stock master cylinder
E46 slave cylinder

[R3VM3UP]

Everything bolted together find with my setup and didn't make any strange noises, etc at startup. Vehicle is not on the road just yet.

The combo that Terra suggested is the factory combo that is known to work but there should be plenty of others that will work as well. IIRC you can't use a regular E36 M3 pressure plate with the E46 S54 flywheel because the bolt pattern is different.

[terraphantm]

The OEM setup on an S54 Z3M is the Euro E36 flywheel with the E36 M3 clutch kit (disc and pressure plate)

[968Reckless]

I found that the springs on the hub of the E34 M5 clutch I bought interfere with the E46 M3 pressure plate's self adjusting mechanism.
Can an E36 M3 or E34 M5 pressure plate bolt up to an E46 M3 flywheel.

Edit: I ended up purchasing an E36 M3/Z3M S54 clutch disk and plan on using it with my E46 M3 flywheel and pressure plate.

so how did this setup work for you? considering the same thing.

[R3VM3UP]

I found that the springs on the hub of the E34 M5 clutch I bought interfere with the E46 M3 pressure plate's self adjusting mechanism.
Can an E36 M3 or E34 M5 pressure plate bolt up to an E46 M3 flywheel.

Edit: I ended up purchasing an E36 M3/Z3M S54 clutch disk and plan on using it with my E46 M3 flywheel and pressure plate.

[BMW_TUNER]

I have always been told to use the flywheel that matches up with your tranny. I am running a zf 320 with a e36 M3 LTW flywheel and pressureplate behind my S54 and other then installing the clutch disk backwards it works flawlessly( although it is a bit rattly). Making other combos work is a matter of overall thickness of assembly bolt pattern of FW and pressure plate and the proper TO bearing. That is stuff that can be measured and compared but if it were me I would say get an upgraded e36 Ltw flywheel and clutch assembly and go with that. They are cheap. Relatively speaking

[harjunv8]

Was there ever a definitive answer to this?

Will an s54 with e46 m3 flywheel and PP work with a sprung e34 m5 s38b36 pressure plate? I'm using the 5 speed 328i/m3 ZF gearbox.

Thank you.

[nando]

BMW used DMF's for years, including on some E30s - so I'm not sure that statement has any validity.

If going with a LTW flywheel on an S54, I'd consider upgrading the harmonic damper. Mainly because the DMF is so much heavier, that alone absorbs some of the harmonics.

as far as it causing transmission damage - I'm sure it reduces some shock on the drivetrain. But the flywheels themselves wear out faster and need replaced, and also cost far more. Solid flywheels are typically used with sprung hub clutch disks, so it's not like there's no damping capability.

[R3VM3UP]

Well generally what you see in production vehicles is that a solid disk is used with a dual mass flywheel while a sprung disk is used with single mass flywheels. Both are a method to damp the drivetrain and both have been implemented in millions of productions cars. While I have no doubt that a DMF helps smooth the perceived engine operation and clutch engagement I find it tough to believe that they actually improve reliability of the driveline vs. the alternative of a sprung clutch with SMF. LS engines, 4.6 modular, etc come with solid flywheels and were produced in massive numbers. Maybe that's not a good comparison because apparently inline sixes are more prone to secondary imbalance than crossplane V8s. On the other hand Ford went with a DMF on the gt350 which also uses a flat plane crank whereas the normal crossplane 5.0 uses a single mass, so I'm sure there is some relevance there. Wikipedia has some good info on this in their engine balance article and on the inline six article, but nothing conclusive.

BMWs shift to DMFs also coincides with their shift from a niche performance brand to a mass market luxury sport brand, so the switch to DMFs could be as much about customer perception as it is about reliability. We probably will never know for sure.

Regardless, plenty of people run SMFs on the S54 with seemingly no ill effects on reliability though admittedly that can be difficult to nudge accurately. I'll almost certainly end up with a DMF to start with, though I may swap to a lightweight SMF at some point in the future.

[Andrew325is]

Yeah a lot of BMWs have came with single mass flywheels, but I don't think any production models have since the early 90's. LuK claims "competitor solutions that use rigid disc flywheels can quickly lead to transmission damage." Maybe they just want to sell their DMFs ;), but it sounds reasonable given the science behind it.

[R3VM3UP]

why risk it.

Because...

a. I don't even have the car yet (still searching for the right one), only the S54 so I don't want to get too far ahead of myself yet.
b. BMW states that the DMF can be used for 2 clutches, and plenty of people on M3F do this with no issues.
c. I have 2 other vehicles already so downtime really isn't an issue if I have to drop the trans to swap clutch components sooner than I otherwise would.
d. Focusing on the essentials to get the vehicle running without excessive costs is the top priority for me. Optimizations can come later.

[R3VM3UP]

The DMF spring rates and damping characteristics are matched to the engine to counteract torque spikes produced during each cylinder combustion to protect the gearbox and other drivetrain components

That sounds like you just described a harmonic balancer. I'm not trying to start an argument or question people unnecessarily but I would need more evidence than a few stackexhange posts to believe that. A vast array of vehicles (including BMWs) do not come equipped with dual mass flywheels, and many people switch to aftermarket single mass flywheels on vehicles that do come with DMFs. This is purely anecdotal evidence as well but I'm not the slightest bit concerned about driveline damage from not running the proper DMF.

edit: Didn't mean to come off as rude, and I don't dispute the fact that the DMF is used to damp vibrations, but I don't think it is intended to protect the drivetrain, I think it is mainly for driveability and the driver's perception of "smoothness".

[butters]

The US E36 flywheel will work just fine, but it won't optimally reduce vibrations. I'm not sure how much you could notice the difference though. It's probably just a little smoother with the correct flywheel. And don't forget to only use a brand new DMF because the springs wear out. It should be replaced every other clutch change.

That was my thinking as well, with the difference in RPM there has to be some good reason. While not noticeable to the driver, the harmonic effect on the crank and bottom end might be significant, at least it was enough for BMW to build the cars with an entirely different flywheel.

I think on a budget you can get away with a "used" flywheel, there are specification checks for play in the assembly that can be verified. But for something that requires a transmission drop, why risk it.

[Andrew325is]

The Euro S50s (including S54) have different torque curves than the US S50 & S52 and the DMF spring rates and damping characteristics are matched to the engine so that's why they use a different DMF. The US E36 flywheel will work just fine, but it won't optimally reduce vibrations. I'm not sure how much you could notice the difference though. It's probably just a little smoother with the correct flywheel. And don't forget to only use a brand new DMF because the springs wear out. It should be replaced every other clutch change.

According to this thread, the DMF is specifically designed for the engine to counteract torque spikes produced during each cylinder combustion to protect the gearbox and other drivetrain components, and of course also reduces vibrations and engagement chatter. It could then be possible that a single mass flywheel or the wrong DMF with a powerful engine like the S54 could cause damage to the gearbox and drivetrain.

[R3VM3UP]

Good catch when I checked it looked like the pressure plate and clutch were the same. I must have forgotten to check the flywheel. Either way it sounds like either one will work, I'm not sure the difference between the flywheel though.