Clutch and Lightweight Flywheel

[mz3onturn7]

I have done a fair amount of research in regard to the various clutches and flywheels that are available for our cars and at this time I am considering 3 different setups. I haven’t been able to come up with too much feedback in relation to 2 of these setups and the information and feedback that I have read about the UUC configuration is not very encouraging. I hope this thread will generate some new discussion about these products and provide some useful information that will assist others and myself when deciding which clutch package to purchase.

Firstly, my s52 M roadster is making close to stock power with the only significant modification being a 3.73 LSD. It is mostly a street driven car with the occasional track day or autocross event. I understand that a clutch should be chosen based on the amount of power that the vehicle makes and installing more clutch than what is needed just makes the car less enjoyable to drive. I have read that it is not recommended to machine the dual mass flywheel that comes as OE on our cars. This presents a great opportunity to upgrade to a lightweight single mass flywheel when changing out the clutch. The problem with the lighter single mass flywheel is the associated gear chatter which can be minimized with a sprung hub clutch disc such as the e34 M5 Sachs OE unit below:

The clutch kits that I would like to discuss are as follows:

1) Bimmerworld kit - $849.00 :

- Proprietary JB Racing aluminum flywheel - (approximately 10 lbs)
- e34 M5 Sachs OE sprung hub clutch disk
- e36 M3 Sachs OE pressure plate

http://store.bimmerworld.com/e36z3--...-kit-p743.aspx



2) Turner Motorsport kit - $1,445.80 :

- JB Racing aluminum flywheel - 10 lbs
- e36 M3 Sachs Heavy Duty sprung hub clutch disk
- e36 M3 Sachs Heavy Duty pressure plate

http://www.turnermotorsport.com/p-17...wheel-kit.aspx



3) UUC Stage 2 kit - $974.00:

- UUC aluminum flywheel - 8.5 lbs
- e34 M5 Sachs OE sprung hub clutch disk
- e34 M5 Sachs OE pressure plate

http://store.uucmotorwerks.com/light...utch-p194.aspx



The Bimmerworld kit and the TMS kit both include JB Racing flywheels although according to Bimmerworld their flywheel is made specifically for them to work in conjunction with the clutch kit described above. I believe that the reason it differs from the typical JB flywheel is because it is designed to be run with the e34 M5 disk and the e36 M3 pressure plate. The TMS kit includes a Sachs HD or “Sport” clutch kit that can hold more power. This is not necessary for my application however I do appreciate that it includes a matching e36 M3 disk and pressure plate.

The UUC set up includes a UUC flywheel that has had some negative reviews. This is probably due to UUC selling more kits than any of their competitors but it still raises some concern. The UUC setup includes the same e34 M5 clutch disk as the Bimmerworld kit however it uses a matching e34 M5 pressure plate that seems to cause a different clutch feel.

I hope that some of you knowledgeable gear heads will share your thoughts on this subject and help others and myself to decide which way to go when choosing a clutch and flywheel package. Thanks in advance.

[Bear Grylls]

If you go UUC your only concern is if you will ever get what you ordered

All the other companies offer similar packages and personally I would order from bimmerworld or turner, both very easy to work with

E34 m5 clutch is nice, do it

Edit: weird they only sell half the m5 setup. Just buy the flywheel and order the stock clutch through BMW

[BenFenner]

I understand that a clutch should be chosen based on the amount of power that the vehicle makes and installing more clutch than what is needed just makes the car less enjoyable to drive.

Just to clarify, and this is no small detail here, the amount of TORQUE that the vehicle makes determines the "amount" of clutch you need. (Available traction matters to a degree as well, but can usually be ignored.)

Would you mind adding the advertized weight of the JB Racing flywheel to your first post (if known)?

I can tell yah I'd rule out option #2 right off the bat unless you plan on making gobs more torque than stock.

[maxmoto]

Excellent post, very useful info

[mz3onturn7]

If you go UUC your only concern is if you will ever get what you ordered

All the other companies offer similar packages and personally I would order from bimmerworld or turner, both very easy to work with

E34 m5 clutch is nice, do it

Edit: weird they only sell half the m5 setup. Just buy the flywheel and order the stock clutch through BMW

From my conversation with the Bimmerworld sales dept. it is my understanding that the e34 M5 disk is used because it is a sprung hub disk that is readily available. I was also told that the M3 pressure plate is used to maintain the same clamping force as a stock M3 clutch and the same pedal feel. It is also my understanding that the M3 plate weighs 1.5 lbs less than the M5 plate and this JBR flywheel is made exclusively for Bimmerworld to accommodate this exact clutch configuration.

I hope someone here has some experience with this product or a similar setup and is willing to share some insight. Even if all of this info is accurate I still agree with you, I don't like the idea of mixing parts together unless it has been tried and tested. Prior to speaking to Bimmerworld I had the impression that you couldn't mix clutch components due to several factors including the different stack height and the shape of the flywheel. I have never purchased from Bimmerworld but I imagine that if their kit didn't work together they would have stopped selling it a long time ago.

Here is a picture of the JB Racing flywheel:

Just to clarify, and this is no small detail here, the amount of TORQUE that the vehicle makes determines the "amount" of clutch you need. (Available traction matters to a degree as well, but can usually be ignored.)

Would you mind adding the advertized weight of the JB Racing flywheel to your first post (if known)?

I can tell yah I'd rule out option #2 right off the bat unless you plan on making gobs more torque than stock.

Weights have been added, thanks for pointing that out. The Bimmerworld 'approximate 10 lbs' weight is due to the information that I received from their sales department indicating that their unit is proprietary and it is made specifically for their cluch configuration. It may be slightly more or less than the 10 lbs wheel on the JBR website.

I agree with you about the TMS setup. The JBR flywheel is what I want but the Sachs HD is more clutch than I need. I just like that it includes the sprung hub disk with the matching pressure plate.

I am leaning towards the Bimmerworld kit however I would move up to the TMS kit as long as it isn't going to be too aggressive for my application. I would even consider the UUC option if someone can talk me into it. The blue wheel sure looks pretty

[mz3onturn7]

I contacted Bimmerworld for some more information about their clutch kit. Here is my message and their reply:

I would like to clarify a few things about this clutch kit as I am a little bit confused regarding how the M3 plate can be used with the M5 disk.

- Is the same stack height maintained using this configuration or is that not a
concern?
- Why is the M5 plate not used?
- Would the M5 plate work if I wanted to run that instead of the M3 plate or
would that change the stack height?
- How is this JBR flywheel different from the one that they sell on their
website? Is it manufactured to accommodate the M5 disk?

Reply:

"Our flywheel is designed to have the disk spring basket facing the flywheel so the M3 pressure plate works with it.

M5 pressure plate is no stronger than an M3 pressure plate.

It is the correct part for your car we have sold a ton of these kits."


In my opinion this Bimmerworld kit appears to be the best option for a Z making close to stock power. After all of the research that I have done I am under the impression that the JB Racing flywheel is a very high quality part and very well priced compared to the OE dual mass flywheel that would cost approximately twice as much to replace. The e34 M5 clutch disk and the e36 M3 pressure plate are both OEM parts made by Sachs. No one can dispute the quality of these parts and their durability when used in an appropriate application. This Bimmerworld configuration is unique because it is the only setup that I have found that uses OE sprung hub clutch components with the JBR flywheel.

I was hoping that someone here may have commented on their experience with these clutch kits or another kit not mentioned here however judging by the number of replies it appears that this isn't a popular topic to discuss. I will update this thread once I complete this job so others can review it in the future.

[A W]

Did you ever pick a kit to install and which one was it?

[rf900rkw]

I find that bimmerworld is loading the M5 clutch in reverse most interesting. Most (all I've inspected) sprung clutch discs are assymetric. Is this not the case with the E34 M5?

[mz3onturn7]

After much deliberation I ended up going with the Bimmerworld kit which included the SACHS non-adjustable e36 M3 plate, SACHS sprung hub organic e34 M5 disk and the JB Racing aluminum flywheel. I just received the parts a few days ago, here is what they look like:






The clutch disk itself seems to be symmetrical, apart from the spring basket being located on the “transmission side” of the disk. Both sides of the friction surface appear to be the same so I cannot see how flipping the disk to accommodate the M3 pressure plate would be a problem. The flywheel is obviously machined to clear the reversed disk configuration:



The kit also included the unique hardware that is specified for the flywheel installation including the flywheel bolts and gaul plate and the pressure plate bolts. A matching SACHS throw out bearing was also included however the kit did not include an alignment tool, that had to be purchased in addition to this kit.

All of these parts appear to be of high quality and I am looking forward to the end result. I am hoping to start the job tomorrow and I will post some more details along the way.

[Mr Bingley]

Thanks for updating this thread--it's very informative and to the point. I will have to remember to find this thread when I do my clutch. I see you are going with Rouge trans mounts, are you rebuilding the shift pins too while you have the transmission out?

[bobsy852]

To dig up an old thread, I am looking at a replacement clutch and flywheel for my E36 328is (NOT M3) and I have been directed to the UUC and the JB Flywheel.

I agree the JB flywheel looks the better part but can't find many reviews on it. I wondered if the OP was still available to discuss how he found the kit?

I am from the UK and it seems I would have to get the kit imported from the USA as there don't seem to be any suppliers in the UK. SO I NEED it to be right and just bolt on when it gets here.

Will the M5 clutch kit fit my vehicle in the same way it fits the M3's? (not sure how similar the drivetrains are on the 328s vs M3s?)

Thanks for the help

[mz3onturn7]

To dig up an old thread, I am looking at a replacement clutch and flywheel for my E36 328is (NOT M3) and I have been directed to the UUC and the JB Flywheel.

I agree the JB flywheel looks the better part but can't find many reviews on it. I wondered if the OP was still available to discuss how he found the kit?

I am from the UK and it seems I would have to get the kit imported from the USA as there don't seem to be any suppliers in the UK. SO I NEED it to be right and just bolt on when it gets here.

Will the M5 clutch kit fit my vehicle in the same way it fits the M3's? (not sure how similar the drivetrains are on the 328s vs M3s?)

Thanks for the help

Hi bobsy852. The parts listed above installed into to my car with no difficulties and they have held up with no issues so far. The flywheel is light so I do experience some gear chatter however this is mostly due to the 6 speed gearbox that I have fitted to the car and not just my clutch setup. That being said, you should expect some chatter if you install the JB flywheel but it is worth the little extra noise for the improvements in the overall driveability and feedback. As far as how the setup performs I can tell you that the car does rev up more quickly during acceleration but the real advantage comes from how the lightweight flywheel allows the engine to wind up much more quickly when the clutch is engaged resulting in crisper down shifts. The single mass flywheel also provides tighter shifts with greater control and feedback.

The clutch itself is very nice, it grabs well but it is not very aggressive. I would describe the feel of the clutch as a heavy duty version of my OEM clutch kit but when paired up with the JB flywheel, it performs pretty well.

I would suggest that you replace a number of other parts while you are completing this job, you may find this other thread of mine useful:

http://www.bimmerforums.com/forum/sh...ts-of-pictures

Overall I am very satisfied with this setup and I wouldn't hesitate to recommend it to a friend. I hope you find this info helpful.

Andrew.

[CMM3]

I've posted this before in a number of places but it's worth repeating.

When installing any flywheel / clutch kit it's highly recommended to have the flywheel and pressure plate zero balanced as an assembly.
Any engine building shop can do this for around $150.

They are of course suppose to come this way and most are but they can be off or unbalanced and this will cause premature bearing wear.
The shop I had mine done at had seen engine failure as a result of unbalanced aftermarket flywheels being installed on an S52 and when they finally got their hands on it to measure it it was 50 grams out of balance. Typically a stock BMW flywheel will be 0 to 5 grams out. This is still a fair amount but for the average Joe driver who hardly ever revs his engine to 4k this is not a problem. Anyone putting a lightweight clutch/flywheel kit in will likely be subjecting their engine to harder, higher rpm use and this is when it will cause the most harm. To put it in perspective they balanced mine to .025 grams.
It is a very low cost insurance practice to prevent a very expensive alternative.

[ajt36]

+1,000. I had this done even though the UUC kit says "each unit individually balanced." I never took that to mean they were balanced together, so that's what I had done, and together they needed balancing. Clutch works great by the way but I don't know how it would be working had I had not paid to have the kit balanced together before I installed it. Last thing you want to do is pull all that crap apart again over something so simple to take care of upfront.

I've posted this before in a number of places but it's worth repeating.

When installing any flywheel / clutch kit it's highly recommended to have the flywheel and pressure plate zero balanced as an assembly.
Any engine building shop can do this for around $150.

They are of course suppose to come this way and most are but they can be off or unbalanced and this will cause premature bearing wear.
The shop I had mine done at had seen engine failure as a result of unbalanced aftermarket flywheels being installed on an S52 and when they finally got their hands on it to measure it it was 50 grams out of balance. Typically a stock BMW flywheel will be 0 to 5 grams out. This is still a fair amount but for the average Joe driver who hardly ever revs his engine to 4k this is not a problem. Anyone putting a lightweight clutch/flywheel kit in will likely be subjecting their engine to harder, higher rpm use and this is when it will cause the most harmed . To put it in perspective they balanced mine to .025 grams.
It is a very low cost insurance practice to prevent a very expensive alternative.

[95maxrider]

Sorry to bump an old thread, but this one looked pretty relevant to my question!

I have a 1998 M3/4/5 and it needs a new clutch. It came with some no-name steel single-mass flywheel, probably from Ebay. I would like to reuse it if at all possible, mostly because I can't afford a new one right now. I will be getting it resurfaced and balanced with the pressure plate.

My understanding has been that if I have a single mass flywheel (mine weighs 16.6 pounds) I need a sprung hub clutch if I want to daily drive the car. Since the car will only ever have bolt ons, and I'm not into drifting, I want a clutch as close to stock as possible. The cheapest sprung hub disc I was able to find is the E34 M5 disc. I was trying to figure out if I could pair it with the stock E36 M3 PP or if I had to use the E34 M5 PP, but this thread answered that question. I've read that using the M5 PP can cause the pedal feel to get a lot lighter than stock, which I don't think I want, so I started leaning towards the E36 M3 PP. An M5 disc and M3 PP from BW cost about $435.

I just got off the phone with a guy from Turner who informed me that they carry a HD Sachs kit that is sprung, and is made to work well with the JBR flywheel (mine appears to be a JBR knockoff), but they want $871 for it! Yeah, I can't afford that right now, I just had to buy a new/used motor! He then let me know that they run a stock M3 unsprung clutch with a 12 pound aluminum flywheel, and he said the chatter really isn't that bad. My understanding up until that point, from reading as much as I can on the forums, was that if I combine a stock unsprung clutch with a single mass flywheel, the results would be disastrous amounts of chatter. My car does rally-x and auto-x duty, but it is still a street car, and I really don't want much chatter.

So, with all that said, what advice can you guys offer me? A Sachs OEM disc and PP are like $370 on BW. The M5/M3 combo is about another $60. I'm thinking it would be wise to spend the extra $60 to get the sprung disc, but then there's the issue of it all mating up with my unknown flywheel. I assume that as long as the clutch that came out of my car is 240mm, I can use any disc with my flywheel?

Thank you!

EDIT- I should also note that I'm completely unclear about which flywheel bolts I should be using with this single mass unit. I assume the stock OEM bolts for the dual mass won't be correct? The bolts that were on the motor had a normal 19mm head and the total length below the head was 29.3mm. If these are stretch bolts, how do I figure out what length I'm supposed to buy? Can I just use any bolts for single mass flywheels, or is there a chance they're specific to my flywheel?

[bionicbelly]

I really doubt that any clutch other than the brand that is currently on there will work. Maybe the stock clutch will work, but I honestly doubt it. Unfortunately, no one would really know without taking measurements and such. On the bright side, you do not NEED a sprung hub clutch, it is just more forgiving.

[95maxrider]

I really doubt that any clutch other than the brand that is currently on there will work. Maybe the stock clutch will work, but I honestly doubt it. Unfortunately, no one would really know without taking measurements and such. On the bright side, you do not NEED a sprung hub clutch, it is just more forgiving.

Well, there are no markings on the clutch disc to confirm the manufacturer, but the PP is a Sachs Typ MF 240, so there's a decent chance the clutch is the HD Sachs unit. I just measured it and the disc diameter is 240mm, so I'm pretty sure I can use any clutch with the flywheel. Why do you say otherwise?

[bionicbelly]

Purely previous experience with eBay items.

[95maxrider]

Bump! I started a thread with detailed questions about the M5 disc. If anyone can definitively answer any of my questions I would be very grateful!

[bluptgm3]

Stock bolts and they are not torque to yield

Don't rule out Rogue Engineering


Sent from my iPhone using Tapatalk

[95maxrider]

Stock bolts and they are not torque to yield

Don't rule out Rogue Engineering


Sent from my iPhone using Tapatalk

According toe RealOEM, stock bolts are 50mm. The ones that came off the flywheel are 30mm. Now, I suppose they could just be wrong, but I came across a post from Rob Levinson, the owner of UUC, regarding a question about a UUC flywheel:

1) You do need the correct bolts that are shipped with the flywheel, they are not the standard E36 bolts.

2) If you have the correct bolts, they are reusable.

3) Use RED loc-tite! As this is an extremely high-force environment with potentially high heat levels, red is the appropriate type.

Hope that helps!

So, he says you can reuse the bolts, but he also says his aftermarket flywheel requires different bolts than stock.

[heeltouge]

EDIT- I should also note that I'm completely unclear about which flywheel bolts I should be using with this single mass unit. I assume the stock OEM bolts for the dual mass won't be correct? The bolts that were on the motor had a normal 19mm head and the total length below the head was 29.3mm. If these are stretch bolts, how do I figure out what length I'm supposed to buy? Can I just use any bolts for single mass flywheels, or is there a chance they're specific to my flywheel?

Just went through this. You will have to measure your actual flywheel thickness as the mating surface to confirm but I used OE E30 single mass bolts on my Clutchmasters Single mass. Measurement worked out correctly.

[95maxrider]

Just went through this. You will have to measure your actual flywheel thickness as the mating surface to confirm but I used OE E30 single mass bolts on my Clutchmasters Single mass. Measurement worked out correctly.

Thanks for the reply! I ended up buying one of the cheap kits off Ebay (single mass flywheel ~14 lbs plus Sachs disc and PP), and it included new flywheel bolts. How long are your E30 bolts?

[caffine]

I've posted this before in a number of places but it's worth repeating.

When installing any flywheel / clutch kit it's highly recommended to have the flywheel and pressure plate zero balanced as an assembly.
Any engine building shop can do this for around $150.

They are of course suppose to come this way and most are but they can be off or unbalanced and this will cause premature bearing wear.
The shop I had mine done at had seen engine failure as a result of unbalanced aftermarket flywheels being installed on an S52 and when they finally got their hands on it to measure it it was 50 grams out of balance. Typically a stock BMW flywheel will be 0 to 5 grams out. This is still a fair amount but for the average Joe driver who hardly ever revs his engine to 4k this is not a problem. Anyone putting a lightweight clutch/flywheel kit in will likely be subjecting their engine to harder, higher rpm use and this is when it will cause the most harm. To put it in perspective they balanced mine to .025 grams.
It is a very low cost insurance practice to prevent a very expensive alternative.

I recently installed a similar kit as the OP:
* JB Racing 10lb flywheel
* Clutchmasters FX350 clutch / pressure plate
* Sachs HD bearing

I didn’t zero balance the flywheel with the clutch.

My question: What would the symptoms be for an unbalanced flywheel/clutch? I’m assuming vibration. But across the RPM range? I am feeling vibrations from the motor around 2200-4200 RPM.

[zellamay]

I know this is an old thread, but people may refer to it. I installed a JB flywheel, Sachs E34 sprung disc (yes, backwards), and Sachs E36 M3 PP, (Same as BW kit). I didn't balance. The vibration is minor but throughout the rpm range. I'm taking it apart soon to balance. I feel pretty dumb. I considered balancing and decided against it. Shop here will do it for around $80. Would have been money well-spent.