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Discussion Starter #1 (Edited)
Greetings Fellow M5ers,

I'm mostly a lurker and I've got my flamesuit on; so, please bear with me. I've spent over 2 hours searching/reading threads and investigating replacement clutches for the beast. After all of the investigative work, I've got a headache and I still require some collective guidance. Any insight would be much appreciated.

Background: I purchased a pre-owned MY 2000 with 42,000 mi from an independent BMW shop. That was almost 3 years ago and I've got 75,000 on the odometer now. The previous owner had already replaced the clutch and installed a lightened flywheel (timing and Brand of replacement parts unknown - the shop said "probably UUC and my sig says UUC but, I'm not really sure). I don't really mind the "chatter" and the increased pedal effort. I do not track this car and do not abuse it. However, I would consider myself a very "spirited" street driver. Last night, I detected slight slippage when I accelerated hard on the highway. As I begin to investigate my options to replace my clutch (and flywheel?) it's coming down to this -

1) How much performance gain can be attributed to the LW flywheel - is it worth the chatter (I realize that the engine can spool up faster and deccelerate faster - but, if I drove a stock car would I be able to notice the performance difference - e.g. If the clutch and LW flywheel are both trashed - and I opt to go straight OEM will I detect a "de-tune")?
2) How do I know whether the LW flywheel is still good?
3) If the shop says that the LW flywheel is OK - can I match to any aftermarket clutch (e.g., Spec Euro stage 2+, Brecus, or similar)?
4) Finally, what's typical - replace BOTH flywheel and clutch or just the clutch?

Thanks for reading (and replying?)

Bubbaschill
 

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Shill account for CNS Racing
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153 Posts
Greetings Fellow M5ers,

I'm mostly a lurker and I've got my flamesuit on; so, please bear with me. I've spent over 2 hours searching/reading threads and investigating replacement clutches for the beast. After all of the investigative work, I've got a headache and I still require some collective guidance. Any insight would be much appreciated.

Background: I purchased a pre-owned MY 2000 with 42,000 mi from an independent BMW shop. That was almost 3 years ago and I've got 75,000 on the odometer now. The previous owner had already replaced the clutch and installed a lightened flywheel (timing and Brand of replacement parts unknown - the shop said "probably UUC and my sig says UUC but, I'm not really sure). I don't really mind the "chatter" and the increased pedal effort. I do not track this car and do not abuse it. However, I would consider myself a very "spirited" street driver. Last night, I detected slight slippage when I accelerated hard on the highway. As I begin to investigate my options to replace my clutch (and flywheel?) it's coming down to this -

1) How much performance gain can be attributed to the LW flywheel - is it worth the chatter (I realize that the engine can spool up faster and deccelerate faster - but, if I drove a stock car would I be able to notice the performance difference - e.g. If the clutch and LW flywheel are both trashed - and I opt to go straight OEM will I detect a "de-tune")?
2) How do I know whether the LW flywheel is still good?
3) If the shop says that the LW flywheel is OK - can I match to any aftermarket clutch (e.g., Spec Euro stage 2+, Brecus, or similar)?
4) Finally, what's typical - replace BOTH flywheel and clutch or just the clutch?

Thanks for reading (and replying?)

Bubbaschill
This thread should help you

http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/154813-what-clutch-would-you-buy.html
 

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Discussion Starter #3
Thanks Fast M5 -

I read that thread previously and it was very informative. The endorsements/testimonials for the CNS setup were especiallycompelling. My interpretation is that you may be able to get the best of both worlds - no chatter and increased performance and that resolves my issue. But, I'm still left wondering

1) How does one determine whether I can salvage my existing LW flywheel? If it OK - are some/all clutches (OEM and aftermarket comapatible)?
2) Does anybody have any quantifiable information that would illuminate the positive performance effect of a LW flywheel?

I guess it boils down to - if the LW flywheel has appreciable gains, I'll either keep it (if it's still good) and match it up to a replaceement clutch or go with an equivalent aftermarket LW flywheel. If the gains are negligable, (based on my driving habits and limited mods) I would lean towards reverting back to OEM.
 

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I'm assuming your LTW Flywheel is a single mass one which can usually be resurfaced and salvaged by any machine shop assuming there are no cracks or major heat damage to it. I would stick with your LTW Flywheel if you could since you already own it and spend the $100-200 bucks to have a shop machine it. Performance wise, you're right there isn't a ton to be gained from a LTW flywheel but they do rev up faster and rev matching when downshifting makes things much easier. Not necessary really for the street but I wouldn't bother to buy a new OEM flywheel if it were me. Too much $$$$ for my taste.

As far as which clutch to go it doesn't sound like you need anything more than OEM or slightly upgraded kit from Brecus. I would contact Aaron directly and see if you two can't work out something for your needs.

M5 (E39) Brecus/DXD Performance Clutch Kit - Brecus Motorsport
 

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Discussion Starter #5
Based on the chatter - I'm assuming it's single mass...does resurfacing (assuming there aren't cracks or major heat damage) compromise the integrity of the LWT flywheel?

I hear you about the $$$ consideration - the least expensive OEM flywheel that I was able to locate was $586 - If I can keep my exisiting flywheel it would be nice to keep the $586 (minus the resurfacing costs) in my pocket.

Thanks for the guidance - it helped alot
 

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Based on the chatter - I'm assuming it's single mass...does resurfacing (assuming there aren't cracks or major heat damage) compromise the integrity of the LWT flywheel?

I hear you about the $$$ consideration - the least expensive OEM flywheel that I was able to locate was $586 - If I can keep my exisiting flywheel it would be nice to keep the $586 (minus the resurfacing costs) in my pocket.

Thanks for the guidance - it helped alot
No it should not compromise it. I have had single mass flywheels resurfaced on a number of occasions as have tons of my other friends who track/beat on their cars regularly. But again, it all comes down to the condition of the flywheel. A shop that will machine it/mill it should have the ability to xray it to to make sure there are no weakened spots in the flywheel. A shop here locally will machine and xray a flywheel for $150. Some people will skip the machining process and attach a sander to a compressor and use that but I wouldn't recommend that if you have the means ($$$) to have it done right. If you can save that money, buy a Feramic clutch from Brecus and never worry about replacing a clutch again.
 

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Discussion Starter #7
Got it - Many thanks for the information!

Yep - I'm all over the Brecus Euro stage 2+ - I just hope that it's compatible with my flywheel...if I can keep it in service.
 

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Shill account for CNS Racing
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Thanks Fast M5 -

I read that thread previously and it was very informative. The endorsements/testimonials for the CNS setup were especiallycompelling. My interpretation is that you may be able to get the best of both worlds - no chatter and increased performance and that resolves my issue. But, I'm still left wondering

1) How does one determine whether I can salvage my existing LW flywheel? If it OK - are some/all clutches (OEM and aftermarket comapatible)?
2) Does anybody have any quantifiable information that would illuminate the positive performance effect of a LW flywheel?

I guess it boils down to - if the LW flywheel has appreciable gains, I'll either keep it (if it's still good) and match it up to a replaceement clutch or go with an equivalent aftermarket LW flywheel. If the gains are negligable, (based on my driving habits and limited mods) I would lean towards reverting back to OEM.
They also have a CNS direct fit clutch like Brecus' that fits the oem flywheel or a single mass aluminum flywheel.

CNS Racing BMW E39 M5 Direct Fit OEM 9.45inch Power Clutch kit
 
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