[rothwem]

Has anyone here gone with a single-mass flywheel after replacing their clutch? This is for a daily driven wagon with stock power and a stock clutch. Did you notice an increase in NVH? If so, where did you feel the difference, clutch pedal, shifter, everywhere?

This is the kit I'm considering:
https://www.ecstuning.com/b-valeo-pa...pY4aAjwD8P8HAQ

[hassmaschine]

Should be fine. It uses a sprung clutch disk, and is similar in weight to the stock flywheel, so I wouldn't expect much change in NVH. If anything, it will be slightly less smooth, but ultimately last a lot longer since the flywheel doesn't have to replaced again.

for my N52 build, I lucked into a 7lb flywheel that the machine shop accidentally made with the 6 bolt N52 crank pattern, rather than the typical BMW 8 bolt pattern. I think the stock flywheel is around 40lbs, so it should be fun - but this isn't going into a daily driver either..

[justpete]

Just trades a failure prone DMFW for a failure prone sprung hub friction disc afaic. And the flywheel doesn't have a replaceable friction surface. Going to have some gear rattle at idle but probably not a lot or at least maybe it'll be mostly inaudible.

[hassmaschine]

If it's the same weight as the stock flywheel, I don't think you'll have any gear rattle.

now, the 7lb flywheel I'm going to be using.. yeah, that's gonna be loud, and I'm using it on a Getrag 260 that is already known for the "Getrag rattle" sound. lol.

[justpete]

Yeah, maybe. If it's the same weight or more importantly the same moment of inertia which doesn't seem likely but I'm just guessing. Can't remember anymore what my solid flywheel weighs but I remember CM saying it was 17# lighter than stock but that included the whole dual disc clutch. Gear rattle? You bet...

[RoyceE90]

Iv just bought a Valeo single mass conversion kit today, will let you know what it's like when Iv installed it, I drove a mates 116d remapped to 200bhp dpf delete with a straight through yesterday and he has a single mass and if I'm honest it feels loads better and the extra noise is hardly noticeable, hence why I went for one

[rothwem]

Originally Posted by hassmaschine

Should be fine. It uses a sprung clutch disk, and is similar in weight to the stock flywheel, so I wouldn't expect much change in NVH. If anything, it will be slightly less smooth, but ultimately last a lot longer since the flywheel doesn't have to replaced again.

for my N52 build, I lucked into a 7lb flywheel that the machine shop accidentally made with the 6 bolt N52 crank pattern, rather than the typical BMW 8 bolt pattern. I think the stock flywheel is around 40lbs, so it should be fun - but this isn't going into a daily driver either..

Ah, yea. My goal isn't for a race type setup, I've had plenty of light flywheel experience in the past, and while it makes you feel like a superhero when rev-matching downshifts, it sucks 99% of the time.

[rothwem]

Originally Posted by RoyceE90

Iv just bought a Valeo single mass conversion kit today, will let you know what it's like when Iv installed it, I drove a mates 116d remapped to 200bhp dpf delete with a straight through yesterday and he has a single mass and if I'm honest it feels loads better and the extra noise is hardly noticeable, hence why I went for one

Awesome, I'd love to hear how it goes for you.

[DigiDon]

Will not be an issue at all. I've done three of these conversions in customers daily driven cars and no noise and drives great. Pedal feel is a tad bit stiffer. No longer have to worry about dual mass flywheel issues or self adjusting pressure plate junk, disc is pretty high quality. If you were going with an unsprung disc, then you would have a bunch of transmission gear noise.

[justpete]

Originally Posted by DigiDon

Will not be an issue at all. I've done three of these conversions in customers daily driven cars and no noise and drives great. Pedal feel is a tad bit stiffer. No longer have to worry about flywheel issues and disc is pretty high quality.

You and Hass bring great news, thanks! Certainly nowhere close to true with my car but moment of inertia matters.

[DigiDon]

Originally Posted by justpete

You and Hass bring great news, thanks! Certainly nowhere close to true with my car but moment of inertia matters.

On my car now, tranny rattles likes crazy at idle. I'm working with solid flywheel and solid disc with an E36 pressure plate. Its much better with some thicker transmission fluid, but still rattles at idle from time to time, especially if it's really hot from spirited driving.

[justpete]

Originally Posted by DigiDon

On my car now, tranny rattles likes crazy at idle. I'm working with solid flywheel and solid disc with an E36 pressure plate. Its much better with some thicker transmission fluid, but still rattles at idle from time to time, especially if it's really hot from spirited driving.

Cool, gear rattle is loud AF in my car all the time, hot or cold, at idle but it's also a CM 850, lightweight solid flywheel with dual solid hub friction discs. Running Red Line MTL, fwiw.

[Taskmaster]

Oh geeze, way too hardcore for me.

[justpete]

Originally Posted by TheAxiom

Oh geeze, way too hardcore for me.

Loudest thing in the car even with the windows down.

[DigiDon]

Originally Posted by TheAxiom

Oh geeze, way too hardcore for me.

I concur!

Originally Posted by justpete

Loudest thing in the car even with the windows down.

You drive it daily or only track?

[justpete]

Originally Posted by DigiDon

You drive it daily or only track?

It's my daily. Or will be again when it's fixed.

[Phil325i]

Not wanting to rain on anyone's parade, but my indy tells me he's had experience of non-DMFs putting too much shock loading onto the crankshaft, with disastrous results...

[rothwem]

Originally Posted by DigiDon

Will not be an issue at all. I've done three of these conversions in customers daily driven cars and no noise and drives great. Pedal feel is a tad bit stiffer. No longer have to worry about dual mass flywheel issues or self adjusting pressure plate junk, disc is pretty high quality. If you were going with an unsprung disc, then you would have a bunch of transmission gear noise.

Is the stiffer clutch due to the flywheel though? Is it possible to use an OEM clutch and single mass flywheel? I've got a shitty left knee and a stiffer clutch isn't going to cut it.

[hassmaschine]

you could, but it would suck - it would be pretty much on/off. Usually either the clutch or the flywheel is sprung, unless it's a race clutch, but race clutches are not fun to daily drive.

[hassmaschine]

Originally Posted by Phil325i

Not wanting to rain on anyone's parade, but my indy tells me he's had experience of non-DMFs putting too much shock loading onto the crankshaft, with disastrous results...

I don't buy it. BMW used single mass flywheels for years and years. The clutch disk is still sprung.

[rjahl]

Originally Posted by hassmaschine

I don't buy it. BMW used single mass flywheels for years and years. The clutch disk is still sprung.

I don't know much about this detail in automotive engines but in larger marine applications it would be common to calculate drivetrain inertias before finalizing a flywheel damper. Get it wrong and the gear chatter will break things. This can be a silent or noisy killer.

Maybe in a car so many things are similar you don't need to run through all the numbers but i don't see many people discussing how changing inertias can create very damaging harmonics.

Just my two cents.

[hassmaschine]

sure, but in this case the single mass and dual mass flywheels weigh the same - the change in harmonics isn't going to be very much. and the clutch is still sprung. People have been switching from dual mass to single mass flywheels for years.

Now, my 7lb flywheel - is definitely going to require a different damper. Unfortunately they are $900 and Pete says they only made 10..