Lightweight flywheel noise - what exactly causes it?
02-11-2005, 12:34 AM
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Lightweight flywheel noise - what exactly causes it?
The noise emitted by lightweight flywheels on the Z (chattering, cement mixer, gravel in the tranny, etc.) is of course old news to those of us with light weight flywheels. However, I've still never really heard exactly *what* is causing that noise.
The stock flywheel is a dual mass, dampened flywheel, so it's silent.
All the other flywheels (such JWT, Tilton, etc) make the chattering noise.
There is one exception I'm aware of: the Nismo is a single mass flywheel, right? But from what I've read it is silent. Why is that? Perhaps it actually does make noise, and the few posts I saw were misinformed.
I'm just wondering what on Earth makes that noise. I've had older cars with stock single mass flywheels (and have friends that still do), and those don't make any noise. So why are the aftermarket units noisy?
The stock flywheel is a dual mass, dampened flywheel, so it's silent.
All the other flywheels (such JWT, Tilton, etc) make the chattering noise.
There is one exception I'm aware of: the Nismo is a single mass flywheel, right? But from what I've read it is silent. Why is that? Perhaps it actually does make noise, and the few posts I saw were misinformed.
I'm just wondering what on Earth makes that noise. I've had older cars with stock single mass flywheels (and have friends that still do), and those don't make any noise. So why are the aftermarket units noisy?
02-11-2005, 03:49 AM
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The Nismo also makes the noise. I guess they don't make the noise just transfer it where as the stock being two piece and dampened shields the driver from the noise.
02-11-2005, 05:03 AM
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The stock flywheel includes a sprung center as does the clutch assembly. This absorbs any slight variations in engine rpm at low rpms. The light weight clutch and flywheel have no springs at all. Any slight variation in rpm cause the floating center plates of the clutch to rattle against the clutch cover. Think of marbles in a coffee can. Accelerating the coffee will cause the marbles to stay against one side and be quiet. Shake the coffee can and then see what happens. All the noise should go away under hard acceleration when the discs are pinned from load....
Jason(aka MRC)
Jason(aka MRC)
02-11-2005, 06:53 AM
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Originally posted by one3502nv
The stock flywheel includes a sprung center as does the clutch assembly. This absorbs any slight variations in engine rpm at low rpms. The light weight clutch and flywheel have no springs at all. Any slight variation in rpm cause the floating center plates of the clutch to rattle against the clutch cover. Think of marbles in a coffee can. Accelerating the coffee will cause the marbles to stay against one side and be quiet. Shake the coffee can and then see what happens. All the noise should go away under hard acceleration when the discs are pinned from load....
Jason(aka MRC)
The stock flywheel includes a sprung center as does the clutch assembly. This absorbs any slight variations in engine rpm at low rpms. The light weight clutch and flywheel have no springs at all. Any slight variation in rpm cause the floating center plates of the clutch to rattle against the clutch cover. Think of marbles in a coffee can. Accelerating the coffee will cause the marbles to stay against one side and be quiet. Shake the coffee can and then see what happens. All the noise should go away under hard acceleration when the discs are pinned from load....
Jason(aka MRC)
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02-12-2005, 04:32 PM
#12
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Originally posted by 350z4steve
not all all it is as noisy as the rest of the aftermarket ones.
not all all it is as noisy as the rest of the aftermarket ones.
Have you personally heard a 350z with a UR flywheel installed or are you just speculating?
02-12-2005, 11:35 PM
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Originally posted by FritzMan
I was assured by the vendor that it wasn't. Considering the premium over a JWT example, I hope it's not.
Have you personally heard a 350z with a UR flywheel installed or are you just speculating?
I was assured by the vendor that it wasn't. Considering the premium over a JWT example, I hope it's not.
Have you personally heard a 350z with a UR flywheel installed or are you just speculating?
02-12-2005, 11:48 PM
#14
I dont remember exactly waht it is called that causes it... i had a long conversation with Jim Wolf about it...
it is this thing that sends a jolt to the cank for timing and it does it in 3 pulses per second... and it causes that rattle... the stock flywheel is 2 pieces so it somewhat absorbs the sound...
i just cant remember exactly what the part is called off hand...
and isnt the UR flywheel 2 pieces? the timing plate off an AUTO plate or something?
it is this thing that sends a jolt to the cank for timing and it does it in 3 pulses per second... and it causes that rattle... the stock flywheel is 2 pieces so it somewhat absorbs the sound...
i just cant remember exactly what the part is called off hand...
and isnt the UR flywheel 2 pieces? the timing plate off an AUTO plate or something?
02-13-2005, 04:26 AM
#16
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That's a bummer. When you say it 'still' makes that cement mixer sound are you comparing it to the OEM noise (which I can handle). Or is it loud enough that a passenger can hear it and think something's broken? My goal is to keep the car sounding & looking as OEM as possible. It's supposed to be a comfortable daily driver first and hobby car second.
Knowing how your UR sounds, have you heard a JWT example? Are they really that similar?
BTW, as pictured in your link I got a weight of 13.6 lbs. So I think the 12 lbs advertised weight is without the bolt-on steel interface to the clutch.
Knowing how your UR sounds, have you heard a JWT example? Are they really that similar?
BTW, as pictured in your link I got a weight of 13.6 lbs. So I think the 12 lbs advertised weight is without the bolt-on steel interface to the clutch.
Last edited by FritzMan; 02-13-2005 at 04:29 AM.
02-13-2005, 10:56 AM
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Originally posted by FritzMan
That's a bummer. When you say it 'still' makes that cement mixer sound are you comparing it to the OEM noise (which I can handle). Or is it loud enough that a passenger can hear it and think something's broken? My goal is to keep the car sounding & looking as OEM as possible. It's supposed to be a comfortable daily driver first and hobby car second.
Knowing how your UR sounds, have you heard a JWT example? Are they really that similar?
BTW, as pictured in your link I got a weight of 13.6 lbs. So I think the 12 lbs advertised weight is without the bolt-on steel interface to the clutch.
That's a bummer. When you say it 'still' makes that cement mixer sound are you comparing it to the OEM noise (which I can handle). Or is it loud enough that a passenger can hear it and think something's broken? My goal is to keep the car sounding & looking as OEM as possible. It's supposed to be a comfortable daily driver first and hobby car second.
Knowing how your UR sounds, have you heard a JWT example? Are they really that similar?
BTW, as pictured in your link I got a weight of 13.6 lbs. So I think the 12 lbs advertised weight is without the bolt-on steel interface to the clutch.
If you are looking for OEM this and that as far as looks and performance wise then look to not replacing your flywheel or at the very least sticking with the nismo one.
02-13-2005, 05:07 PM
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the stock flywheel is a dual mass unit, which is what helps it absorb engine noise.
Some flywheels are a bit on the louder side, others are not. Having personally run and install the UR on several Z's of various years, there is no noise difference vs stock at any rpm range
Some flywheels are a bit on the louder side, others are not. Having personally run and install the UR on several Z's of various years, there is no noise difference vs stock at any rpm range
02-13-2005, 05:32 PM
#20
Originally posted by Z1 Performance
the stock flywheel is a dual mass unit, which is what helps it absorb engine noise.
Some flywheels are a bit on the louder side, others are not. Having personally run and install the UR on several Z's of various years, there is no noise difference vs stock at any rpm range
the stock flywheel is a dual mass unit, which is what helps it absorb engine noise.
Some flywheels are a bit on the louder side, others are not. Having personally run and install the UR on several Z's of various years, there is no noise difference vs stock at any rpm range
Kwame