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"Numpty" question about clutches and flywheels!

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Old 30 January 2010, 03:17 PM
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Hammer man
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Default "Numpty" question about clutches and flywheels!

Sorry about the silly question folks.....
Imagine you have a car that has, lets say 300bhp, and the same car has a standard flywheel and a clutch which can cope with 300bhp. Lets assume that this is the limit of the clutches capability. If you then change the flywheel for a lighter one and you change all the pulleys for lighter ones, but you make no changes on the engine`s bhp, will the clutch still cope. The car still has 300bhp, but its "pick-up" is improoved cause the engine has less weight to start spinning??
Old 30 January 2010, 05:08 PM
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Glowplug
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Originally Posted by Hammer man
Sorry about the silly question folks.....
Imagine you have a car that has, lets say 300bhp, and the same car has a standard flywheel and a clutch which can cope with 300bhp. Lets assume that this is the limit of the clutches capability. If you then change the flywheel for a lighter one and you change all the pulleys for lighter ones, but you make no changes on the engine`s bhp, will the clutch still cope. The car still has 300bhp, but its "pick-up" is improoved cause the engine has less weight to start spinning??
Let's imagine, youv'e gone to the time and expense of changing the fly wheel, would it not make sense to change the clutch at the same time to one which will do the job with a bit to spare for future mods
Old 30 January 2010, 05:24 PM
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Splitpin
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Originally Posted by Hammer man
Sorry about the silly question folks.....
It is a silly question, although maybe not in the way you'd think.

Imagine you have a car that has, lets say 300bhp, and the same car has a standard flywheel and a clutch which can cope with 300bhp.
Clutches don't cope with power, they cope with torque, and even then you're thinking about it the wrong way. It's not like they will "cope" with x amount of torque and "not cope" with a tiny fraction more.

If you had a car with, to continue(ish) your analogy, 300lb/ft, and a clutch that will clamp 300lb/ft, you will be replacing it very shortly, because given a few more weeks of wear, it will only be able to cope with 290lb/ft, and in a few more weeks, 280, and pretty soon you'll realise it's fecked. That's the thing with clutches, their maximum clamping torque decreases slowly as they wear.

As B13 has already said, if you were going to replace your flywheel, and had a clutch that was only just about holding the car's current torque output, the obvious thing to do would be to replace the clutch when you do the wheel.

And, once all that is accepted, your question effectively becomes moot, because...

Lets assume that this is the limit of the clutches capability. If you then change the flywheel for a lighter one and you change all the pulleys for lighter ones, but you make no changes on the engine`s bhp, will the clutch still cope.
If the clutch is sufficiently worn that simply fitting light flywheels and pulleys was enough to cause it to slip, as I suggested above, even if you didn't fit the pulleys, you would soon be aware of it slipping anyway.

Last edited by Splitpin; 30 January 2010 at 05:25 PM.
Old 30 January 2010, 09:09 PM
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Hammer man
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Thanks for the replies..... both make common sense. Something I sadly lack at times.
Old 30 January 2010, 10:03 PM
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What can a standard Subaru, say a Classic Turbo 2000, clutch take in torque before you need to look at a performance clutch?

Sam
Old 31 January 2010, 09:36 AM
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greatgonzo
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Originally Posted by Saalro
What can a standard Subaru, say a Classic Turbo 2000, clutch take in torque before you need to look at a performance clutch?

Sam
Sam not sure about the classic clutch but iv been told the Hawkeye clutch is strong there's a lot of people on here running a lot of power through the standard clutch.
Old 31 January 2010, 10:55 AM
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dunx
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My std. 2.0 STI six speed clutch gave up at 500 Nm....
Old 31 January 2010, 02:27 PM
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scooby1doo1
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Hijack but dint see the point in a new post, my00 will be needing a yet another new clutch very soon. Getting or looking at lighter flywheels, but on the reseach i have done seems to be alot of mixed feelings as to how light to go.
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