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Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You See

48K views 33 replies 15 participants last post by  Lscman 
#1 ·
I was at a local car club meeting the other night at Kelly-Moss (Hey, I've got sound posey whenever possible so you all think I know a little bit about what I'm talking about!) and I was talking to one of the Porsche techs about my M5 clutch and its replacement. He told me when I had my clutch replaced I should have had a lightweight flywheel installed in place of the dual weight flywheel that comes stock on my car. He said I could get quicker times during high speed driving events. And he said the main handling difference I would notice would be when shifting during around town driving--I would have to be more precise. I think I'm I quoting him correctly, I did have a beer to drink.

Has anyone ever replaced their flywheel with a lightweight one? What brand? What differences in times/driving performance, if any, did you notice?

Thanks for any ideas/advice on this!
 
#2 ·
Anita said:
.... I think I'm I quoting him correctly, I did have a beer to drink....
Anita,

If you would have consumed several beers instead of just one, you'd be certain of what he said (or at least you *think* you understood him) ;)

Sorry I don't have anything constructive to contribute, just being goofy tonight :confused3 ouich
 
#4 ·
FAST 5 said:
To my knowledge, DINAN has two different versions of the lightened flywheel. It appears as though, people opt. to get the stage 1 flywheel over the stage 2, due to the higher noise level which comes from stage 2 flywheel.
Robert
there are quite a few posts of single mass vs. dual mass flywheel -- i put in the Dinan stage 1 lightweight dual mass with clutch replacement and can sometimes maybe notice a difference. this is not high in my list of up-grade priorities
 
#5 · (Edited)
Hey A,

I have a single mass flywheel. Don't go too light as the Beast requiries weight to launch it. Its O.K. for a lightweight P car, but our porky beasts, need a little weight.

That said, the dual mas is incredibly heavy. Instead of going for a lightweight alloy one which usually flys apart, at super insane rpm's and is illegal on a drag strip, I had mine customed out of a special steel. Super strong.

I think (10/45) don't quote me on that number, I had more than a few. :cheers:

Just changing the flywheel really isn't going to produce any large changes.

In for a penny , in for a pound. Clucth, Pressure plate and flywheel all work as one.

Change one, and you really should change all three and remove all the problems forever.

Once the Flexi Dual mass piece of Rubbish is gone, you can then increase clamping pressure. The dual mass is so weak, bmw only use 2,600 pounds clamp. The dual mass can't handle anymore. Get rid of it, go back to a solid single mass, and I have increased clamping pressure to 4,300+ pounds of clamp. That aint slipping for no man, once hooked up.

My 5 button carbotic clucth is super street able and will handle any track situation and all mods. Problem GONE.

I can launch from any rpm. The only thing that burns is the tyres.

I can bark the wheels when hitting fourth on the quarter mile.

I love it. It is a small price to pay to roll over noise at idle. I will get around to raising the idle, as this quietens it right down.

If I am stopped at the lights, and want to let the clutch out, I just hold a light pressure on the accelarator to bring the revs upto 800 and the noise is gone.

But it doesn't bother you inside the car. Its those dam pedestrians giving you a funny look. If it isn't a long stop, I just keep the clutch held in and it is silent.

Anyone who is a track monster, the noise is nothing .

Its loud from outside the car, but Track people know its just rollover noise. It lets everyone know that this beast is not stock. cherrsagai
 
#6 ·
The MIB solution is the only one I've seen that looks suitable for a M5. Other setups are too light and result in terrible noise that's poorly suited to a Corvette, let alone a $75K saloon. Lightweight flywheels are a cool upgrade that lots of people "want", but you won't see significantly improved lap times. The gains are probably on the order of 0.1s a lap...or less, unless you're a real good heel & toe driver. Personally, I would not degrade the streetability of my car chasing down such gains.
 
#7 ·
Anita:

I am probably one of the few M5 owners who have had recent experience with both the Dinan Stage 2 (single mass) and "Stage 1-like" (cut-down BMW dual mass) flywheels. This was all occasioned by the need to install an upgraded clutch following severe slippage experienced at RA with my S2 equipped car. I am using the Sachs Race Engineering pressure plate and disc originally intended for the E46 M3. This clutch has the same dimensions as the stock unit, but is not self-adjusting for engagement point and the Sachs disc will not fit on the stock flywheel without minor machine work to reduce the height of the annular raised boss near the crank flange bolt circle.

The weights of the flywheel/clutch assembly work out as follows:

Stock (dual mass) 52 lbs.
"Stage 1" (dual mass) 44 lbs.
Stage 2 (single mass) 25 lbs.

The reduction in rotational inertia (what resists engine acceleration) will be somewhat greater than the weight reductions shown above, due to the fact that flywheel diameter is also reduced.

As far as driving with the two systems, I would offer the following observations:

General: The improvement in engine acceleration response is noticeable, obviously more so with the Stage 2 setup. This is useful to the driver mainly in the lower gears. The advantage of reduced rotational inertia is largely neutralized, IMHO, by the considerable mass of the M5 and the modest rear axle ratio.

Stage 2 (single mass) flywheel: The Dinan unit is, for my purposes, incredibly noisy. The noise at idle is well documented and more than I expected. However the noise at low speed (1500-2500 rpm) when creeping around in 2nd and 3rd gear is much worse - quite loud and sounds like the transmission is about to fall out. This behavior is totally out of character with the refinement of the E39 M5, also IMHO, and is why I changed to a different flywheel a short time later. Two other issues with the Dinan Stage 2 (or similar aluminum) flywheel deserve mention. First, the very low rotational inertia makes it quite (very) easy to stall the engine on start-up from a stop. Also the steel insert construction is very intolerant of clutch slippage; put a lot of heat into the steel insert and it will permanently "pucker up" like a tufted mattress around the attaching bolts. This effectively reduces the contact area for the disc, making subsequent slippage more likely. This did not happen to me, but I have seen it elsewhere. I would absolutely not recommend using the stock M5 clutch with a steel insert/aluminum flywheel. Mark's (MIB) custom steel single mass flywheel obviously overcomes these last 2 issues, and possibly his use of a sprung center clutch disc reduces the noise.

"Stage 1" cut-down dual mass flywheel: I am presently quite pleased with the combination of the Sachs pressure plate and clutch on this flywheel (I had the original stock flywheel machined and re-balanced by local shops). Engine response is noticeably (if slightly) better, clutch engagement is smooth in daily driving, and did I say it is QUIET. It also locks up with authority. I also second the opinions of others who have observed that shifting is smoother with this flywheel (engine decelerates a little more quickly between shifts). Concern has been raised over the durability of the stock dual-mass flywheel in serious performance applications - specifically the leakage of oil from the dual mass absorber. Anecdotal evidence seems common in the Porsche community. We will see how this goes, and also how durable and slip resistant the Sachs clutch is over time. It is not expensive, compared to a custom unit, and not especially difficult to purchase another stock flywheel and have the machine work done if failures occur at sufficiently widespread intervals - in exchange for the silence and driveability advantages. This last is obviously my personal trade-off, for a car that is primarily street driven and sees the track only a few times a year.

In terms of aftermarket parts, it looks like UUC is getting ready to release an aluminum/steel insert flywheel similar to Dinan's Stage 2, and have found a sprung center clutch disc (from Sachs) that will fit. It is not yet clear (to me at least) which pressure plate they intend to use, whether custom or off-the-shelf, as their other clutch upgrades seem to be applying rxisting BMW parts to lower-rated engines (e.g., M5 pressure plate to E46 M3). A sprung center clutch disc may make the lightweight single mass flywheel acceptably quiet, but a higher clamping force pressure plate will be an absolute must with the composite flywheel.

Hope this helps.

Regards, Dick Roberts
 
#8 ·
Anita,

I've been talking to UUC Motorwerks and they've been testing their LWF for the past couple of months. They've built a LWF/Clutch combination that's supposed to have groundbreaking innovations. There is supposed to be no rattles that is commonly associated with a LWF. I need to give them a call to day to see their progress.
 
#9 ·
RRoberts said:
Stage 2 (single mass) flywheel: The Dinan unit is, for my purposes, incredibly noisy. The noise at idle is well documented and more than I expected. However the noise at low speed (1500-2500 rpm) when creeping around in 2nd and 3rd gear is much worse - quite loud and sounds like the transmission is about to fall out. This behavior is totally out of character with the refinement of the E39 M5, also IMHO, and is why I changed to a different flywheel a short time later. Two other issues with the Dinan Stage 2 (or similar aluminum) flywheel deserve mention. First, the very low rotational inertia makes it quite (very) easy to stall the engine on start-up from a stop. Also the steel insert construction is very intolerant of clutch slippage; put a lot of heat into the steel insert and it will permanently "pucker up" like a tufted mattress around the attaching bolts. This effectively reduces the contact area for the disc, making subsequent slippage more likely. This did not happen to me, but I have seen it elsewhere. I would absolutely not recommend using the stock M5 clutch with a steel insert/aluminum flywheel. Mark's (MIB) custom steel single mass flywheel obviously overcomes these last 2 issues, and possibly his use of a sprung center clutch disc reduces the noise.



In terms of aftermarket parts, it looks like UUC is getting ready to release an aluminum/steel insert flywheel similar to Dinan's Stage 2, and have found a sprung center clutch disc (from Sachs) that will fit. It is not yet clear (to me at least) which pressure plate they intend to use, whether custom or off-the-shelf, as their other clutch upgrades seem to be applying rxisting BMW parts to lower-rated engines (e.g., M5 pressure plate to E46 M3). A sprung center clutch disc may make the lightweight single mass flywheel acceptably quiet, but a higher clamping force pressure plate will be an absolute must with the composite flywheel.

Hope this helps.

Regards, Dick Roberts
Hey Dick,

Yes my sprung centre made puttering around acceptable. I do not get any noise above 1,000 rpm.

The main time is just at idle. You can't here it from inside the car, but you most definitly can from outside.

But its only at idle with the clutch out. So if I keep the clutch in, at idle its perfectly quiet. I still haven't raised my idle limit yet, but that will make it right.

I do it all the time at lights if there are pedestrians about. I apply a light throttle and bring the rpm upto 800. That reduces the noise by around 80% to where it is acceptable.

At 900 it is almost completely gone. and by 1,000 it is totally gone. But now I have a decent clutch and pressure plate, I can launch with revs before clutch. So if I take off at 1,200 it is totally smooth and silent.

To show you streetability of this settup, I can in fact take off with no revs at all. Just start letting the clutch out, however once all the way out, when you apply throttle and you are under the 1,000 rpm, I do get that rattle you soke about with your S2 Setup. But it is only at insanely Low RPM. So the sprung centred clutch really did do a lot in controlling the noise. It didn't totally eliminate it, but it went along way to making it acceptable. :cheers:
 
#10 ·
MIB said:
Hey Dick,

Just start letting the clutch out, however once all the way out, when you apply throttle and you are under the 1,000 rpm, I do get that rattle you soke about with your S2 Setup. But it is only at insanely Low RPM. So the sprung centred clutch really did do a lot in controlling the noise. It didn't totally eliminate it, but it went along way to making it acceptable. :cheers:
Mark:

Thanks for the feedback. I expect the heavier flywheel is a big help in this regard. Did you measure the weight of your setup? The Dinan Stage 2 flywheel weighs about 12 lbs., and the clutch & pressure plare weigh about 13 lbs., for a 25 lb. total.

Regards, Dick Roberts
 
#11 · (Edited)
RRoberts said:
Mark:

Thanks for the feedback. I expect the heavier flywheel is a big help in this regard. :crying: Did you measure the weight of your setup? The Dinan Stage 2 flywheel weighs about 12 lbs., and the clutch & pressure plare weigh about 13 lbs., for a 25 lb. total.

Regards, Dick Roberts
Hey Dick,

No I didn't weigh it ouich and it really bugs me now.

I do know that it is a lot lighter than the Stock Dual mass.

At a guess I would put it between The Dinan Stage 1 and Stage 2. Sought of a 1.3 Stage. :cheers:
 
#12 ·
Light flywheels have the most pronounced effect at lower vehicle speeds when the change in crank velocity is the greatest. The increased mass of a given flywheel will resist changes in velocity, acceleration. At high speed,
engine r.p.m.s don't vary as much as they do in initial acceleration from a stop. Therefore, light flywheels have little or no effect at high speeds. In fact, I surmise that at high speeds, under aerodynamic load, the lighter flywheel may not maintain momentum between shifts as well as the heavier
one, possibly being slightly detrimental.
 
#13 ·
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

Thank you all for the info. Okay, so in what driving events would the flywheel replacement make any sense/difference--for low speed autocross events, which I have not done with my M5, high speed autocross courses (2 miles in size) or a road course like Road America? Also, I think part of the tech's rationale for doing a flywheel swap during the clutch replacement was to save labor costs. I wonder how BMW would like that being done during a warranty clutch replacement ?!?

Bill: I think you are correct about my beer consumption--I really should make it more then one so I can figure out what people are telling me. All the info above may require 2 or 3 at least. Seriously, this past year has been a real learning experiencing for me--I come from a background of never having done any track events and knowing very minimal things about the workings of cars to where I am today, which isn't that much further--HA HA. It's been a steep learning curve, but I've been having a blast doing all I've done.

Anita
 
#14 ·
Ok, my clutch is shot and my dealer won't take care of it under warranty. :mad: So, my thinking is if I have to shell out the $ for a clutch, i don't want to put the same piece of junk that's in there now. however, after reading numerous posts on this clutch issue, I have learned there are tradeoffs and I am now thoroughly confused. I don't like the idea of hearing some trashy sounding noise coming out from my $70k plus car. I also don't want to relpace my clutch in another 20k miles. I would rather fix the problem now and fix it right! The thing that makes me mad is that BMW is refusing to acknowledge that this amounts to what should be considered a design defect.

My question is, since I have to replace the clutch on my dime is it worth it to replace the flywheel when everything is already apart and also spend the extra $ to get a racing clutch? What is the strongest and most cost effective solution without having to listen to that lash noise?
 
#15 · (Edited)
robmorris3 said:
My question is, since I have to replace the clutch on my dime is it worth it to replace the flywheel when everything is already apart and also spend the extra $ to get a racing clutch? What is the strongest and most cost effective solution without having to listen to that lash noise?
Hey Rob,

Its simple. To fully remove the problem, you introduce the roll over noise at idle only.

Your choice. A little noise, only when the clutch is out, at idle, (Most of the time it is in and silent), or you can replace your clutch all the time.

The real heart of the problenm is the Dual mass flywheel and lack of clamping pressure.

Because the dual mass is so flexible, they can't apply decent clamp. Remove the dual mass, and you can up the clamp.

But the dual mass is what keeps it quiet. The choice is your. A little roll over noise, or continually facing the problem.

By raising your idle, it will quieten down the roll over noise. Its only audible from outside the vehicle. After around 900 rpm its gone. (I'm rarely below 2,000 let alone 900.)

So with an after market exhaust and raised idle it is under control. Its still there, but it is acceptable.

What is very acceptable, is Launching at 4,000 Rpm and only frying the tires and not the clutch. :cheers:
 
#16 · (Edited)
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

To help illustrate the difference in engine acceleration between a stock flywheel and a lightweight flywheel, we have a video that demonstrates it rather well. It's from an E46 3-series, but the effect is identical with the E39 M5:

.avi format (816K): http://www.uucmotorwerks.com/flywheel/FlywheelComparison.avi

.mov format (1.35MB): http://www.uucmotorwerks.com/flywheel/FlywheelComparison.mov

RRoberts said:
In terms of aftermarket parts, it looks like UUC is getting ready to release an aluminum/steel insert flywheel similar to Dinan's Stage 2, and have found a sprung center clutch disc (from Sachs) that will fit. It is not yet clear (to me at least) which pressure plate they intend to use, whether custom or off-the-shelf, as their other clutch upgrades seem to be applying rxisting BMW parts to lower-rated engines (e.g., M5 pressure plate to E46 M3). A sprung center clutch disc may make the lightweight single mass flywheel acceptably quiet, but a higher clamping force pressure plate will be an absolute must with the composite flywheel.
I wouldn't say it's similar to Dinan's Stage 2 at all... in fact, it's not similar to anything ever put into the M5. In all reality, it's what should have been put in originally.

We have been keeping it quiet until it is ready to be released, but that date is just around the corner, before the end of February.

There are a few "field install" testers using production-quality components right now. Expect them to post their experience in the next few days.

Full details to come soon, but right now I will share these facts:

- It is a sprung-hub design for power pulse variation absorption (reduces transmission rattle).

- Total rotating mass of the flywheel and clutch assembly is reduced 13.5lbs compared to the OE M5 setup. This amount is not as much as some of the really lightweight flywheels, but it is enough for a noticeable increase in throttle response and significant rattle reduction (and complete elimination in some M5s).

- Basic clutch package is rated close to 600lb-ft. Optional clutch packages are rated to just under 900lb-ft. Got a supercharger? The UUC flywheel has already been installed behind a supercharger-equipped S62. Clamping force and materials are really beyond anything currently available.

- Pricing as a complete kit including clutch and everything you need will be comparable to other brands' flywheel alone.

- Clutch pedal feel is completely unchanged.

Simply put, it is quite literally "a lot of clutch" that will cure this ongoing issue we see with M5/Z8 owners replacing the OE setup so often. You can finally expect normal clutch life... UUC has been testing this clutch package now for over two years. When you do need a replacement clutch, the components are readily available and affordable.
 
#17 ·
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

Rob Levinson said:
To help illustrate the difference in engine acceleration between a stock flywheel and a lightweight flywheel, we have a video that demonstrates it rather well. It's from an E46 3-series, but the effect is identical with the E39 M5:

.avi format (816K): http://www.uucmotorwerks.com/flywheel/FlywheelComparison.avi

.mov format (1.35MB): http://www.uucmotorwerks.com/flywheel/FlywheelComparison.mov



I wouldn't say it's similar to Dinan's Stage 2 at all... in fact, it's not similar to anything ever put into the M5. In all reality, it's what should have been put in originally.

We have been keeping it quiet until it is ready to be released, but that date is just around the corner, before the end of February.

There are a few "field install" testers using production-quality components right now. Expect them to post their experience in the next few days.

Full details to come soon, but right now I will share these facts:

- It is a sprung-hub design for power pulse variation absorption (reduces transmission rattle).

- Total rotating mass of the flywheel and clutch assembly is reduced 13.5lbs compared to the OE M5 setup. This amount is not as much as some of the really lightweight flywheels, but it is enough for a noticeable increase in throttle response and significant rattle reduction (and complete elimination in some M5s).

- Basic clutch package is rated close to 600lb-ft. Optional clutch packages are rated to just under 900lb-ft. Got a supercharger? The UUC flywheel has already been installed behind a supercharger-equipped S62. Clamping force and materials are really beyond anything currently available.

- Pricing as a complete kit including clutch and everything you need will be comparable to other brands' flywheel alone.

- Clutch pedal feel is completely unchanged.

Simply put, it is quite literally "a lot of clutch" that will cure this ongoing issue we see with M5/Z8 owners replacing the OE setup so often. You can finally expect normal clutch life... UUC has been testing this clutch package now for over two years. When you do need a replacement clutch, the components are readily available and affordable.
Sounds good! Please let me know when this comes out asap. My clutch is about to go and this is my daily driver.
 
#18 · (Edited)
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

Rob Levinson said:
It's from an E46 3-series, but the effect is identical with the E39 M5:
Hey Rob, I don't mean to burst your bubble, but saying that something has the IDENTICAL effect as an M3 will not win you favours here.

Full details to come soon, but right now I will share these facts
- It is a sprung-hub design for power pulse variation absorption (reduces transmission rattle).
Reduce does not = Eliminate.

- but it is enough for a noticeable increase in throttle response and significant rattle reduction (and complete elimination in some M5s).
So why elimination in some M5's and not others? Is that Identical to the M3's as well? I haven't looked at the clips as yet, but were they filmed with one of the GOOD ones? Do you see my point.

Clamping force and materials are really beyond anything currently available.
Since you don't put a number on that, we can't quantify it.
The reason why I say my Pressure plate gives 4,200lbs + clamp is because I saw the guy measure it, and his gauge only read that high. So I am interested in you Quantifying your statement in comparison to "Whats out there."

- Clutch pedal feel is completely unchanged.
If that is true, then you haven't done a very good job, as the Stock pedal feels limp and like crap. Most guys would welcome a slightly firmer clutch pedal, one that has some feel to it.


Simply put, it is quite literally "a lot of clutch" that will cure this ongoing issue we see with M5/Z8 owners replacing the OE setup so often. You can finally expect normal clutch life... UUC has been testing this clutch package now for over two years. When you do need a replacement clutch, the components are readily available and affordable.
Rob, I'm sure your product will be welcomed, but overstating its abilities will not. Call it as it is. Everyone who knows anything about clutches and Pressure plates and flywheels, knows how difficult it is to produce something that can do everything.

It is an extremely difficult balancing act. Showing an M3 as an example really is totally irrelavent.

I look forward to seeing and HEARING, the setups from the guys who have it.

Of course I expect it to be hugely better than stock, (Thats not hard, the bar was pretty low.)

But lets see if you deliver on the Noise factor.

Regards Mark.
 
#19 ·
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

MIB said:
Hey Rob, I don't mean to burst your bubble, but saying that something has the IDENTICAL effect as an M3 will not win you favours here.
Actually, I mis-wrote. I did mean to write "similar", not "identical"... and "similar" in the way that there is a similar change in any car equipped with a lightweight flywheel. Whether it is the M5, a 3-series (the video car is a 330i), a Mustang, or a Honda... the effect of a lightweight flywheel can be generally demonstrated by that video.

You should look at the video - it's showing the difference in engine acceleration speed between the OE flywheel and a lightweight setup. It's quite interesting.


MIB said:
Reduce does not = Eliminate.
I believe I made that quite clear... "significant rattle reduction (and complete elimination in some M5s)" in that post.

MIB said:
So why elimination in some M5's and not others? Is that Identical to the M3's as well? I haven't looked at the clips as yet, but were they filmed with one of the GOOD ones? Do you see my point.
Answering those in reverse order, the video shows nothing regarding rattle or not. It's a close-up shot of two tachometers showing rev speed, no audio whatsoever.

As to why in some M5s and not others, there are a number of factors that determine transmission rattle due to removal of the dual-mass flywheel's power pulse variation absorbing capabilities:

1) Build tolerance of each individual transmission - as much as we like to think BMWs are "minted" perfectly, the truth of the matter is that variations exist between components. In these transmissions, some are looser than others, more likely to rattle at idle with a lightweight flywheel.

2) Wear of the individual transmission - whether thorough mileage, contaminants, or hard use, the fact remains that each transmission wil change it's propensity to rattle as time passes, and each one in slightly different ways than every other one.

3) Condition or type of transmission fluid - thinner fluid has less damping effect than heavier fluid, that's a basic concept. The OE fill changes viscosity as it ages or is used (and more or less depending on usage style). Likewise, the use of alternate fluids will change the damping effect. Whether the M5 has OE, Swepco, Royal Purple, Redline, or Amsoil will change how much damping there is from viscosity and the effects of the additive packages.


MIB said:
Since you don't put a number on that, we can't quantify it.
The reason why I say my Pressure plate gives 4,200lbs + clamp is because I saw the guy measure it, and his gauge only read that high. So I am interested in you Quantifying your statement in comparison to "Whats out there."
We will be supplying data on the website shortly. Bear with me, I am not ducking your question but looking to answer it more completely in due course.


MIB said:
If that is true, then you haven't done a very good job, as the Stock pedal feels limp and like crap. Most guys would welcome a slightly firmer clutch pedal, one that has some feel to it.
Then I have the answer you will really like; our setup includes a different slave cylinder, matched to this clutch. The original slave cylinder can be retained, and the effect is a firmer pedal feel. Best of both worlds - the M5 owner can choose the pedal feel he prefers.

MIB said:
Rob, I'm sure your product will be welcomed, but overstating its abilities will not. Call it as it is. Everyone who knows anything about clutches and Pressure plates and flywheels, knows how difficult it is to produce something that can do everything.
Again, not to duck the question, but I ask a small amount of patience until we publish the details. I think you will see the capabilities of this setup have not been overstated.

MIB said:
Of course I expect it to be hugely better than stock, (Thats not hard, the bar was pretty low.)
Trust me, my disappointment in the original BMW design is substantial. The fact that the E39 M5's clutch is not significantly different than that of the 5-series from 20 years ago despite the big increases in power and chassis weight is simply astonishing.

MIB said:
But lets see if you deliver on the Noise factor.
While I would never guarantee an absolute absence of slight rattle (see the list of factors above), I can say that the net result is not like any other aftermarket lightweight flywheel, and is similar to a lightened OE flywheel.
 
#20 · (Edited)
Thanks for your speedy reply Rob,

Just keeping you honest buddy. :hihi:

It is quite clear that UUC have gone the extra yards to come up with a soloution.

My setup was a one off, designed specifically to my needs. It was never meant to see production. I upgraded everything to 10 Inch for extra strength.

As soon as I saw you guys also went to a sprung centre, I knew we were looking at a serious fix. I also have a sprung centre. Mine is a five button Carbotic Clutch plate 10 inch, and a Sachs Customised pressure plate so the pedal pressure is just firm, not to heavy, not too light.

My Flywheel was a work of art. It was made from some special Steel, as I drag race as well as use it for daily driving. Whilst it is lighter than the stock Dual mass, it still has enough weight to launch the Beast, and it is expodentially stronger. So it will also handle the huge clamping pressure. We used the Stock Ring Gear, have You?

Good Job. cherrsagai

Your not off the hook yet, but you most certainly have gone the extra yards for a Production unit. :byebye: :thumbsup:
 
#21 · (Edited)
I am learning a great deal about our clutch. I like the fact that the OEM clutch doesn't make any noise. I seldom drive the car hard off the line but do step on it when im already on the freeway. I haven't any problems with my clutch, but notice its nearing the end of its Clutch Travel.

Has anyone here replaced their own clutch? ?????? :cool2:
I think I'd like to try the install myself :eek:oohhh:
 
#22 ·
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

MIB said:
Thanks for your speedy reply Rob,

Just keeping you honest buddy. :hihi:
Never a problem.

MIB said:
My setup was a one off, designed specifically to my needs. It was never meant to see production. I upgraded everything to 10 Inch for extra strength.

As soon as I saw you guys also went to a sprung centre, I knew we were looking at a serious fix. I also have a sprung centre. Mine is a five button Carbotic Clutch plate 10 inch, and a Sachs Customised pressure plate so the pedal pressure is just firm, not to heavy, not too light.
Nice work! How do you find that clutch? I'd imagine a little touchier than OE?

MIB said:
My Flywheel was a work of art. It was made from some special Steel, as I drag race as well as use it for daily driving.
Sounds like a 1050 steel or similar. That's the kind of thing required for the more aggressive clutch materials, and is what we use for the friction surface. This kind of material will take any kind of clutch including a sintered iron racing disk.

MIB said:
Whilst it is lighter than the stock Dual mass, it still has enough weight to launch the Beast, and it is expodentially stronger.
Have you weighed the entire setup to determine the reduction compared to OE?

MIB said:
We used the Stock Ring Gear, have You?
Certainly.

MIB said:
Your not off the hook yet, but you most certainly have gone the extra yards for a Production unit. :byebye: :thumbsup:
I think you'll be pleased. :D
 
#23 · (Edited)
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

Rob Levinson said:
Nice work! How do you find that clutch? I'd imagine a little touchier than OE?
You would think, but now I have more km's up on it than I got from the stock one. First has smoothed out considerably since I first had it installed. All the other gears were perfect from the start. I guess it just needed to be broken in.


Sounds like a 1050 steel or similar. That's the kind of thing required for the more aggressive clutch materials, and is what we use for the friction surface. This kind of material will take any kind of clutch including a sintered iron racing disk.
It was 1045. They said something about dormant or docile properties. Can't really remeber, but there was a good reason why they chose 1045. This guy is a Top class engineer that builds all soughts of clutches for all soughts of interesting things, not just race cars.


Have you weighed the entire setup to determine the reduction compared to OE?
Thankyou, for bringing this back to haunt me. ouich No one asked the Question at the time, and I didn't think to weigh it. So I don't know. I can remember feeling the difference between it and the stock setup, and mine was considerably lighter. But that isn't saying much. On lightweight flywheel terms, mine is Heavy. They wanted to keep loads of strength and they said some extra weight to launch such a heavy beast. So whilst mine is lighter than the Stock Dual mass, most would consider it Heavy for a single mass. It retained Thickness, to handle abuse.
It won't flex, it is solid. cherrsagai

Remember we put the flex back were it belongs, in the clutch plate.
 
#25 · (Edited)
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

Gentlemen:

I rarely post however I am a regular fly on the wall so to speak.

As for the UUC clutch that Rob is about to put on the market, awesome!!!

The expected high quality parts along with fit and finish, beautiful. But where this unit shines is the manner in which it operates.

I own the super charged Z8 shown on this board and communicated with Rob throughout the developement of the package. We installed it last weekend without a hiccup and once completed the results were amazing. Pedal feels like OEM, no clutch engaged idle rattles, no chatted when being engaged, and I am here to tell you this baby can take the torque and horsepower. I am so happy with the piece that I have already ordered 3 more clutch assemblies for other projects presently under way.

FYI, the surface area is almost 50% greater, the throwout bearing is almost 50% larger in diameter, and if you use the full face composite material it is a clutch that once installed can be serviced by any BMW dealer or ? In my case we built a 6 puck composite faced disk so I may have a minor delay should I need to service otherwise this is the ticket.

I deal with alot of high end, high horsepower cars and much as Rob shared this is what BMW should have installed from day one. As for Dinan, as much as I like their products when speaking of their clutch assembly is like comparing apples and oranges. Theirs is functional with numerous compromisses whereas this is a no compromise direct replacement upgrade, and I mean to say again this is a wonderful and significant improvement that should be considered by all M5 and Z8 owners.
 
#26 ·
Re: Dual Mass Flywheel .vs. Lightweight Flywheel--What Performance Differences Do You

shadowman said:
Gentlemen:

I rarely post however I am a regular fly on the wall so to speak.

As for the UUC clutch that Rob is about to put on the market, awesome!!!

The expected high quality parts along with fit and finish, beautiful. But where this unit shines is the manner in which it operates.

I own the super charged Z8 shown on this board and communicated with Rob throughout the developement of the package. We installed it last weekend without a hiccup and once completed the results were amazing. Pedal feels like OEM, no clutch engaged idle rattles, no chatted when being engaged, and I am here to tell you this baby can take the torque and horsepower. I am so happy with the piece that I have already ordered 3 more clutch assemblies for other projects presently under way.

FYI, the surface area is almost 50% greater, the throwout bearing is almost50% bigger, and if you use the full face composite material it is a clutch that once installed can be serviced by any BMW dealer or ? In my case we built a 6 puck composite faced disk so I may have a minor delay should I need to service otherwise this is the ticket.

I deal with alot of high end high horsepower cars and much as Rob shared this is what BMW sould have installed and as for Dinan, as much as I like their products when speaking of their clutch assembly is like comparing apples and oranges. Theirs is functional with numerous compromisses whereas this is a no compromise direct replacement upgrade, and I mean to say again this is a wonderful and significant improvement that should be considered by all M5 and Z8 owners.
Thanks for the post! I just hope I can baby my existing clutch until this UUC version comes out.
 
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