Thread: Fidanza 143621 flywheel, 8.5lbs. or 10.5lbs.?

Hello,
Can anyone please help clarify the actual weight of a new 108-tooth Fidanza 143621 flywheel? About half of the online retailers I have checked lists it at 8.5lbs., while the other half lists it at 10.5lbs.

Fidanza used to list both the 109-tooth 143201 flywheel and the 143621 at 8.5lbs., but it turned out that the 143621 actually weighed in at around 10.5lbs.
From this comparison picture it is obvious why.



That was a few years ago, and I have come across people stating that since then Fidanza has switched to the lighter design with more of the backside aluminum shaved off for the 143621 as well. However, I am not sure how reliable those statements are.
Can anyone please confirm if this is true, or if the 143621 still weighs 10.5lbs.?
Thank you.

i'd always thought that the 143621 was 6kg and the 143201 was 4.5kg. but i just checked

http://www.fidanza.com/files/catalog.pdf

and they are listed at 10.5 lb (4.8kg) and 9.9lb (4.5kg)

I have owned two of the 109 tooth flywheels. both were the lighter design. They are supposed to weight 8.5lbs but I don't think I ever weighed either.

You did check out this thread from the Manifesto right? http://www.sr20-forum.com/information-library/8164-sr-flywheels.html
You probably found your image there?
How come you didn't post the question in there?
Why are we in the VVL section?

The 108 tooth flywheel weighs more because it uses the heavier outer ring gear to make OBD2 sensors happy.

That's not really the case Kyle. Maybe you need to re-read the flywheel thread too. Or just read the OP? Info is in there too... =/

More aluminum involved in the meat on heavier flywheels ve less aluminum on the older ones?

Way to go Fidanza for sharing wrong info with Vadim and I....

Remember BenFenner, 1-3-4-2, and P10 rear LCA are different than B13 LCA.

Who knows, the ring gear might even account for up to 50% of the weight gain?

Haha silly you, BenFenner.

Thanks for correcting my misinformation, sir.

My apologies, but the information about the Fidanza flywheels in there is the 'old' information I was referring to, and I chose to post it in the VVL forum since the 108-tooth flywheel is specific to the VVL motors, as far as I know. However, any recent information on the flywheels is appreciated.
Thank you.