By the way I found the weigh in figures for the A12 and A14 flywheels.

A12 = 9.6kg
A14 = 9.9kg

I weighed them a couple of times to be sure...

Didn't realise they would be that heavy, also didn't realise there would be that little difference between the two.

on a datsun? must have been a CA A15 flywheel. I never got to weigh mine but mine was a mid 70's probably A14 and was pretty heavy.

I just had a flywheel lightened, it WAS 26LBS! Now down to 15.5 LBS. What a difference!!!

3.7 kg is fine on the street. The engine just slows quicker betweeen changes.

The only problem with the chrome moly wheels are they are made one piece and if the ring gear gets damaged its the whole flywheel shot..

those aren't really for the 'street'

3.7kg

Mine is 6kg and I wouldnt want it any lighter. 3.7 would be a bitch to drive on the street.

fidanza makes one too. It's probably USD.

you can get a stock flywheel down to 2/3 of it's weight safely, and less if you like excitement!

I suppose it's the old saying: speed costs/how fast do you want to go?

you can take weight off other places that the flywheel and have it do the same thing. Lighter crank pulley, use underdrive pulleys on the alternator and water pump.

The idea is to have less rotating mass, some places are cheaper than others to take it out of.

damm, american dollars, #### u yanks and your high performence products

i found a flywheel on this japanese sight and they have flywheels for the a12, JUN ULTRA LIGHTWEIGHT CHROMOLY FLYWHEELS, and this company do flywheels for an a12 weighing just 3.7kg but cost $485 and im not sure what currency they use, us, au dollars, anyway they definetly do it for me but i dont have that type of cash

Hmmmm

I'll have to actually check my results, but they were both in the range of 9kg, maybe 9.1 and 9.9.

And I have also felt the significant diference in weight between the two when picking them up. One came from an A12, the other from an A14. I was also surprised that the difference in weight was so little.

I took both down to the engine builder, his preference was to work on the A14 flywheel - so that's the one he's got.