mt2000

It appears that a few board-members have invested in a lighter flywheel and have responded very positively about this modification ?

Questions :

1. How does this mod increase performance - ?increased hp or ?lighter mass to spin
2. Does this modification increase clutch wear ? Therefore should the clutch also be upgraded when considering this modification ?

VisualEchos

As I understand it, the performance gain is two fold. The first being less weight, and the second being that the engine revs quicker. Beyond that I can't see the benifits.

Luis

Actually that's the same advantage. The drive train (including the flywheel)is typically responsible for about 15% of power drop. A lighter flywheel reduces this loss. So, it doesn't generate power, it's just more efficient.
How much? I personally suspect very little, but others may differ.

I am installing the Toda Flywheel next week. The reason however has little to do with the advantage described above. I am looking for easier heel and toe and rev matching. With the clutch disengaged the engine should be able to spin up and down faster if you're shedding weight from the flywheel. This, I hope, should help drivability.

VisualEchos

Thanks Luis, I knew you would know.

mt2000

Thanks.. makes sense. And I like the idea of being able to match revs quickly during a down gearchange. But do you know the answer to my second question.

Luis

I doubt it. Clutch is a wear item anyway. The flywheel, however, may be a different issue. If it's softer than stock it may wear. I'm sure however that there will be a lot of testimonials stating fuss free flywheel upgrades.

This is my first flywheel upgrade so I don't qualify...

pfb

As I understand it, a light flywheel does little to improve "power", but does positively affect "feel", and allows the engine to rev quicker (with clutch in) and slow down faster (again, with clutch in) allowing a more sporting driving technique... Light flywheels can make a car less "smooth", however.

Case in point: Audi A4 1.8T, very nice motor, but folks constantly complain about poor clutch in throttle response, due to its overweight flywheel. Probably engineered that way so the little motor can launch the relatively heavy car smoothly...

AusS2000

Not really. You're assuming that the only advantage of decreased mass is due the decreased inertial mass.

I think S2Kguy is also alluding to the fact that, not matter how little, the decreased in mass is also a decrease in vehicle mass, and hence acceleration.

I suspect the latter is minimal but with guys spending $1500 on an exhaust which is 6lbs lighter it's gotta be relevant to some.

mt2000

Why should a lighter flywheel make a car less smooth ? Should it not do the opposite, ie should the the engine not rev quicker with a lower rotating mass ?

AusS2000

A flywheels store potential energy. It takes energy to get them spinning, but it also takes more energy to slow them. So if you rev the engine, then drop the clutch the stored potential energy is added to your accelerational force. The heavier the flywheel, the smoother the acceleration.

Light flywheels mean you can increase revs quicker, but when you load it up (engage clutch) it slows down easier. So you need more revs before clutch engagement to get the same pickup.