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Flatulence, normally you don't need to by a new flywheel. Clutch kits do come without flywheel. Unless your warrants replacement when incur the extra expense.

Which brings us to your next question, if you want to incur the extra expense bear in mind that when installing a lightweight flywheel you should also think about getting software to support it lke from powerchip. At least that is what I was told. If you are looking for a quicker spool up, and better response go for it but there are tradeoffs as well. There have been countless posts threads about clutches on this board, I'm sure you will find all sorts of answers. The question you need to ask YOURSELF is what am I looking for when I change my clutch?
 

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Greco said:
Flatulence...
hiha hiha You just got the first good laugh out of me today!
I would call UUC or PM Rob L. and see his input on the matter. Even if you dont end up buying through them I am sure he would be willing to spend the time to steer you in the right direction.
:cheers:
 

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Fart said:
Smoth daily driving and no slippage when shifting hard from 2. to 3rd and 3rd to 4th Is what I am looking for.

I am not going to modify my beast regarding HP so I dont need a monster clutch.
Well IMO if you are not looking into modifying your beast then don't even think about going to a lightweight flywheel. Stick with the dual mass and only change it if it needs to be changed.
 

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i put in the Dinan lightweight dual mass flywheel before switching to UUC after burning out that clutch

my advice is that the lightweight clutch will make a very minor difference vs the cost -- wait until you really need a new clutch
 

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Fart said:
Smoth daily driving and no slippage when shifting hard from 2. to 3rd and 3rd to 4th Is what I am looking for.
Is this the sign of a clutch that's on the way out ?

The reason I ask is that I've just taken delivery of my car and noticed this happening when I was driving home, however it only seemed to happen when I was going full bore from 2nd to 3rd or 3rd to 4th. Initially I thought it was driver error and that I'd not quite managed to get it into gear (I'd just traded up from an auto 4.6is X5), but it's happened a few times since then.

I was suspicious of the clutch when I bought the car, but the dealer assured me that it had been checked and everything was OK with it. The car has just done 40k miles, so a new clutch is probably on the horizon - I figure that if this is a sign that the clutch is going, then I can get the dealer to pay for a new one !
 

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I believe clutch slippage occurs when the car is in gear, clutch completely depressed and while pressing on the gas the engine rpm vs the speed of the car does not match. Kind of like when you smoke the tires, the car doesn't move that fast forward but the tires spin like crazy but in the case of clutch slippage its the clutch thats spinning like crazy against the flywheel instead of the tires on the asphalt.
 

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I'm in the same boat, am I correct that if all I'm looking for is normal no modication Beast with less clutch slippage then I'm good with just SPEC stage 1 clutch kit? Is the flywheel a must with the SPEC stage 1 or am I good with just the clutch kit and pressure plate itself?
 

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I'm in the same boat with you guys 40k and slippage from 3rd, 4th, and 5th. It's definetly that time
 

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Beamer_usa said:
I'm in the same boat with you guys 40k and slippage from 3rd, 4th, and 5th. It's definetly that time
Slipage when driving hard ad shifting over 3000rpm can make a new clutch slip. But its something that I want to get rid off.

Slipage is when the car is fully engage in gear and then starts to rev when hitting the accelorator without the car gaining speed.
 

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Fart said:
Smoth daily driving and no slippage when shifting hard from 2. to 3rd and 3rd to 4th Is what I am looking for.

I am not going to modify my beast regarding HP so I dont need a monster clutch.
The word "monster" could be taken a few ways. A 400 HP street car needs a substantial & strong clutch. An 11" clutch is prudent for V8 powerplants over 200 HP. Most mfrs have been employing clutch sizes over 10"" for years. BMW is the oddball, as they tweaked and fiddled with a tiny 4cyl clutch size with very poor resuults. The stage 1 organic disks offer excellent driveability that you expect in a production car. A smaller race clutch may hold up, if you're willing to put up with whiplash, poor modulation and other shortcomings you get with race compound disks. There are many reasons why OEM mfrs don't use smallish brakes and clutches mated to race material pads and disks. They are not what you want in a daily driver. The only compelling reason I can see to stick with a small clutch is to exploit OEM warranty replacement opportunities. The labor fees are substantial, so paying to install a small clutch can backfire in the long run.
 

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Some info about clutch slippage, and fly-wheels...

BMW made it that way on purpose. A heavier flywheel protects the crank shaft from getting hair-line fractors. Also, a small clutch will burn out and "slip" before you tear up a drive shaft, the rear end, and other parts in the drive system.

The idea is..."Hey if we are going to give Joe Public a fast and high torque car, most are going to drive the sh*t out of it and break lots of things that they are going to want US to pay for!" Solution...a soft clutch that will burn out if you drive it too hard or too fast, and if you do, YOU will have to pay for it, not BMW. (wear & tear item)

So it fun and neat to get a really light flywheel and larger clutch...but remember, something breaks, then you are going to have to pay to fix it. Racing cars cost big $$$$. I guess you could get some sponsers and stick their name on the car!!!!

:M5launch:
 

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M5Pageco said:
Some info about clutch slippage, and fly-wheels...

BMW made it that way on purpose. A heavier flywheel protects the crank shaft from getting hair-line fractors. Also, a small clutch will burn out and "slip" before you tear up a drive shaft, the rear end, and other parts in the drive system.

The idea is..."Hey if we are going to give Joe Public a fast and high torque car, most are going to drive the sh*t out of it and break lots of things that they are going to want US to pay for!" Solution...a soft clutch that will burn out if you drive it too hard or too fast, and if you do, YOU will have to pay for it, not BMW. (wear & tear item)

So it fun and neat to get a really light flywheel and larger clutch...but remember, something breaks, then you are going to have to pay to fix it. Racing cars cost big $$$$. I guess you could get some sponsers and stick their name on the car!!!!

:M5launch:
The management or control of crankshaft flex due to cylinders firing is largely controlled by the harmonic damper assembly mounted on the crankshaft snout (front of the motor). Undersize dampers are a bad idea, unless they have superior fluid technology. Lighter flywheels largely are a non-issue wrt crankshaft flex damping because the flex occurs across the shaft. Holding one end at a constant angular velocity does not effectively reduce harmonics or twist. Be aware that most automatic transmissions have flywheels made of stamped sheetmetal that weigh almost nothing....even designs with locking torque converters that completely bypass the hydraulic damping capabilities of the torque converter in higher gears.
 
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