Pro's and con's - Lighter flywheel

[Lebsteif]

I'm going to replace my clutch and noticed that my flywheel needs to be replaced as well.

 

I'm in doubt to go for a stock flywheel or light flywheel.

 

I have read that the benefits are less strain on the drivetrain, faster acceleration, but it drops faster in rpm as well (due the less rotating mass)

 

Is it worth it or is better to go for stock?

[Scott]

Depends on your driving style and where you will be using the car. It can be an absolute nightmare as a daily driver if you get caught up in traffic. Stalling is twice as easy and accelerating slowly is twice as jerky lol.

 

Takes a bit of getting used to but it definitely makes a difference to the acceleration when booting it.

 

Scott =op

[Jake]

I would never have a lightened flywheel again. The slight performance increase is no way worth the downsides, in my opinion.

The revs drop far too quickly between gear changes for my liking. But the worst thing is the gearbox rattle they cause.

 

If you want your car to sound like a bag of spanners and for folks to keep asking you what's wrong with your car then you'll love it!

[jevansio]

Mine sounds like a bag of spanners too, it needs a lot of revs to pull away (people outside must think I'm a c*ck but I have to do it to avoid stalling).

[marc_p]

sorry but this is more important:d

 

Lebsteif, who is that woman in your avatar's?

[Ark]

I got rid of my lightened fly as soon as I got the car. Sounded awful, bitchy to drive - it had to go. They're fun for weekend cars, or track day demons, but not for something you have to pootle about in regularly.

 

I've also heard they can reduce fuel economy...not sure whether there's any truth in that though.

 

If you have some cash rattling around and want to reduce strain on the drivetrain, better to get a carbon fibre drive shaft instead - a lot of the same benefits, without the tiresome noises.

[Matt H]

sorry but this is more important:d

 

Lebsteif, who is that woman in your avatar's?

 

High Chief Camel Toe

 

or maybe its little big boobs

[Ian C]

*hovers over "Move Thread" button*

[Thorin]

*hovers over "Move Thread" button*

 

Quick, post something technical, er, erm....

[marc_p]

Quick, post something technical, er, erm....

 

What is the exact combustion teperature....ratio's..........has he gone.....

[bolarbag]

I hear people saying this all the time, but I have a lightened flywheel and my car is silent, I replaced the pilot bearing at the time dont know if that makes a difference, I have the rps cyn-r-g flywheel, its not the lightest of the bunch(I've seen some at 7kg) but its defo an improvement

 

If you have some cash rattling around and want to reduce strain on the drivetrain, better to get a carbon fibre drive shaft instead - a lot of the same benefits, without the tiresome noises.

 

I've never came across a CF driveshaft thats actually lighter than stock, all the aftermarket ones come with heavy duty couplings sometimes making it heavier, their primary use is to prevent cars flipping into the air

[Ian C]

A decent CF prop will weigh less, but figure that as less overall car weight and not less drivetrain rotating mass as it's such a small diameter it means nothing to the overall drivetrain loss. It can take an enormous amount of twisting force but sod all lateral loading which means it's great for drag racing, big power cars, and as mentioned already, the safety factor - if a coupling lets go, it hits the deck or the drive tunnel and explodes rather than polevaulting the car into the sky or sawing your legs off.

 

However they cost in the region of £1000+vat so that's probably a tad more than a flywheel.

 

Personally I'd stick to the stock flywheel as it's nice and damped for your comfort and gearbox longevity

 

-Ian

[SteveR]

Personally I'd stick to the stock flywheel as it's nice and damped for your comfort and gearbox longevity

 

Right, that's my mind made up. Can I have a stock flywheel with the OS Giken twin plate clutch? Someone reckoned I could, someone else reckoned I couldn't.

[bolarbag]

Personally I'd stick to the stock flywheel as it's nice and damped for your comfort and gearbox longevity

 

Wouldnt the comfort aspect come from the clutch side i.e pressure plate?

 

I thought the dampener was to reduce unwanted forces on the engine itself not the primarily the gearbox?

[Digsy]

Wouldnt the comfort aspect come from the clutch side i.e pressure plate?

 

I thought the dampener was to reduce unwanted forces on the engine itself not the primarily the gearbox?

 

The flywheel acts as a "node" - that is a part of the crankshaft that should not be vibrating torsionally.

 

Try twanging a ruler over the edge of a desk. First do it while holding the desk end very firmly. You will note that hardly any of the "twang" gets transmitted to your fingers. Now do it olny holding the ruler very loosely. You will probably find that the ruler jumps up and down under your fingers.

 

That's part of what the flywheel does. Its inertia "holds" the transmission end of crankshaft at a constant velocity, regardless of how much or how little the rest of the cranktrain is vibrating. Like your ruler, the part furthest away frm the anchor point is vibrating the most, so that's where you put the vibration damper (front crank pulley).

 

If you reduce the inertia of the flywheel (most usually by reducing its mass) then you limit its ability to hold that point of the cranktrain at a constant speed, and so some of the vibrations pass into the gearbox. The noise you then hear is the geartrain constantly loading and unloading as the torque through them reverses.

 

Some engines that want a low-inertia flywheel for driveability but don't want the associated geartrain nise fall back on a dampened or dual mass flywheel where the gearbox end is physically decoupled from the drivetrain vibrations.

 

So basically, if you replace a high-inertia, dual mass flywheel with a low-intertia, single mass one, you can expect a load of noise from your gearbox.

[Lebsteif]

It's not the weight reduction reason why i was thinking of a lighter flywheel, but to find ways to extend the life on a W58 tranny.

 

I have read on supraforums.com that you get a chattering noise form the light flywheel when they are made too light.

Looks like i will go for a stock flywheel.

 

sorry but this is more important:d

 

Lebsteif, who is that woman in your avatar's?

 

It's Leah Dizon