Flywheel compatability NA-NB

[Woo]

I've heard people putting 1.6 flywheels onto 1.8's and vice versa for different reasons.
However, I was wondering what is the difference (if any) between the NA8 and the NB8A (B or C) flywheel?

Any insight would be great.

Bazz

[Boags]

Each one got lighter.

[Woo]

Thanks Boags
Does that mean that a clutch kit for a NB will be suitable for an NA, just more inertia?

I'm hopeful that the NB kit I'm having built will go onto FFGs NA8 flywheel. Increased rotational mass, in this application, is a good thing as it may stop the snail going to sleep on gear changes.

Bazz

[bigdog]

Aren't you fitting a Lenco Woo???

[Woo]

Why would I ?
There is only one way that would fit and that would be to re-tunnel the car.
The Mx5 box behind a MX5 motor has always been the plan, the clutch is where the planned weak point is. Just minimising the weakness.

Still asking the question " Will an NB clutch direct fit an NA8 flywheel"

Bazz

[Boags]

Yes.

[Woo]

Thanks Mr Boags

[Boags]

Kein Problem.

[wun911]

Dr Physics...

If the weight is not evenly distributed across the flywheel.
Eg I go ahead and shave off 5 kg from the peripheral edge (diameter remains the same).
How do I go about calculating moment of inertia (MOI)?

[Woo]

Hey Dr MicroBio,
Hows your integration?
I=int(r^2 dm where r is radius and m is mass. Of course I is the MOI.

for a uniform thickness and density you can always substitute dm=pt dA where p = density, t= thickness and A is area

If you weigh it and measure the diameter I'll calc it for you Wun

Bazz

Edit: Nah, it's actually more complicated as it's a non-uniform volume. So it would be at least a double integral, possible a triple. I'll think on it and get back to you.
EDIT EDIT: It's a triple integration and I would need the crosssectional dimensions as each "thickness" would be integrated separately and then summed together (integrated again)

[Woo]

It wouldn't be a good idea to remove 5 kg from a stock cast flywheel. It would be to thin and would most likely shatter at revs. Get a chromoly disc and fit a ring gear and cast friction surfaces. That way you get light weight and a good clutch action.

Probably work out cheaper than a Toda or Fiddy