Why is the MCS flywheel so much heavier than the MC flywheel? I don't remember exact figures but I seem to recall something near 25 lbs for the MCS and 17 lbs for the MC. In deference to those of us still on the shallow part of the techie learning curve, is there a simple way to explain this?

thanks

 

28 lbs for the MCS. If i were to Guess Its due to 2 major factors and these are steming from th 02-04 MCS. 1) the VERY Tall first Gear 2) the VERY HEAVY STOCK tires and rims you can get on it.

As for my understand on Flywheels they serve two Purposies (ok my spelling sucks)

1) Main reason. is to carry the engine to the next power stroke. Most race cars will go to as light as possible to accomplish this. To the point that in my Sprint car i didnt run a Flywheel at all. Since the car didnt have a clutch or gear box. it was either nuetral (off) or in gear (running) so the drive train and the tires acted as my Flywheel

2) To smoothing carry power from one point to another. to get the car rolling from a dead stop there is a transfer of power from the motor to the wheels. If that transfer is to great the motor stalls. That 28lbs Flywheel carries alot of energy and isnt easy to stop but thos 56lbs wheel and tires known as "S-Lites" with runflats takes a lot to get moving and would need a heavy flywheel to do so smoothly.

Hope this makes some sense.
Mugami

 

No other guesses?

 

Well for one, the MCS flywheel is a dual mass unit while the MC one is single. I believe it was added to keep it smooth at idle. The SC probably adds a decent amount of drag and the designers found a single mass unit caused some unwanted noises.

 

To reduce gear box noise.

 

But I'm trying to figure out why the MCS flywheel is heavier than the MC flywheel. With no other info, "to reduce gearbox noise" would be easily interpreted as meaning the MCS flywheel needs the extra weight because the Getrag box much noisier than the Midlands box.....I know that's not what you meant. So, there must be more to it then gearbox noise.....right?

 

I think Mugami gave you an answer...not a guess

 

Cool, but I'm having trouble believing they would have made such a decision over the s-heavies bit. After all, they're just the heaviest option rather than the only option. As far as the tall first gear, I hear the 05-06 gearing is much better.....yes? In fact, if it's as much better as some say (I haven't seen the numbers), it seems like the 05-06 flywheels could have been lighter.

 

I just remembered I still have that 2002 tech article (from the German issue of MTZ) on the S Powertrain. It mentions the flywheel in the "Gearbox Concept" section.

"The front-mounted transverse configuration was a major design challenge when it came to the length of the engine/gearbox unit." etc, etc, etc, "Because the length of the engine is largely fixed, depending on the spacing between the cylinders, the length restriction on the powertrain as a whole determines the length available for the gearbox."

"There was no room in the Mini's engine compartment for a conventional two-shaft six-speed gearbox with all the gears arranged one behind the other. Working with the Getrag company, BMW therefore developed a compact three-shaft gearbox with one input and two output shafts, in which certain gearwheels are used twice to permit a considerably shorter gearbox."

"To avoid unpleasant rattle from the gearbox, a dual-mass flywheel is located between it and the engine. This is a spring-mass system and operates in the super-critical range, thus isolating torsional crankshaft vibration from the gearbox."

Looks like 002 wins the cupie doll.

 

That's the article I was trying to find while posting my last comment. Most people don't like diesel sound in a gas engine

 

If you're right kurvhugr (and I'm not denying you are) then that would also explain the many posts regarding gear box, clutch bearing, etc. noises people with MCSs experience. I personally enjoy an extremely annoying and frustrating gearbox related noise (dull rattle) in neutral with the clutch disengaged at a stop light. Push the clutch in and it goes away. It is almost certainly related to the dual mass flywheel and Getrag 6 speed gearbox, but is it worth taking back to the dealer? I think not...

cheers,

 

Hey, don't call me "right," I'm clueless but found an article to quote.

For those who haven't seen it yet, that article was a really big deal for those of us trying to figure out these little beasties way back in 02. It talks about alterations to the engine between Cooper and Cooper S. I don't know how to upload a pdf to the site, but you can still find it online - search for the title "The Mini Cooper S Powertrain" - it was published in something called "MTZ Worldwide" in 2002 (volume 63).

 

That explains why its Dual mass but still doesnt explain the weight

 

Oh, I guess I assumed that it was heavy because it was dual mass.....suddenly remembering the old bit about what happens when you assume.....

 

That's what I meant and your fallowing post answers why. There seems to be a lot of gear backlash with this box. With my solid light flywheel the noise can be insane, but once in a while it is absolutely quite. I can't wait to install a limited slip so I can see up close what exactly is going on in there.

 

BMW seems to like dual-mass flywheels. Their products use them extensively, including in my E36 M3. (Well, originally - a UUC lightweight flywheel lives in it now.) Yet the M3 has a smooth inline 6 and a conventional 2-shaft gearbox.

Neil
05 MCS
96 M3