Flywheel question

[tydon]

Where do i go to lighten a fly wheel are there any gains in doing this?

[rslegy]

Less rotating weight = eaiser to rev

Bnt maybe or an engineering shop

[loner]

pro: engine revs up faster.

con: engine slows down faster.

[Koom]

I had my factory one lightened at an engine rebuilders.

Then I bought an aluminium one that weighs half as much again. Still can\'t say if I\'ve ever noticed the difference it makes but it gives me warm fuzzies knowing that I have a super light weight one.

[tydon]

What was cost on lightening?

[Koom]

Not much from memory. Maybe $50? Was years ago though.

[GC8E2DD]

And what weight did you end up with Koom?

[Koom]

Think it was about 7.5 or 8kg on the factory one. The engine builder said he didn\'t want to take too much out of it, then the next day handed me half a bloody flywheel. I was expecting it to just have a skim but he took a huge amount of meat out of it.

It lasted for years though, through a couple of cars and I never had an issue with it.

The Aluminium one is rediculously light though. Down below 4 kg. No issues at all with driving around town with that and I\'ve had that one in the RS since 2007 or so.

disclaimer: I never used to write any of the numbers down when I weighed things so all this is off 6 year old memories...

[Marky]

There\'s a couple here -

http://www.subaruspeed.co.nz/products/lightweight-flywheel-47kg < 4.7kg?

http://www.subaruspeed.co.nz/products/lightweight-flywheel-sti-54kg <- 5 and a bit STi one?

Worth tossing up to buy pre-made or lightening yours I spose

[titian]

Just be a bit careful lightening the std flywheel. 8) Esp if you are also going to run hi clamp force on the pressure plate.

Deflection of the std lightened flywheel will occur way before a hi grade steel or correctly manufactured ali one.

Deflection will equal destruction!! :\'( :\'(

Yep! Been there done that

[boon]

Just don\'t get too carried away about making it light... the loss of mass and angular momentum means you have to give it an extra wee stab of the throttle when lifting the clutch and the engine will drop revs extremely fast when the clutch is in, meaning on spirited downshifts you really ought to make an effort towards rev-matching. There seems to be a nice middle-ground somewhere between the stock one and a super super light one.

[kamineko]

 boon said:

Just don\'t get too carried away about making it light... the loss of mass and angular momentum means you have to give it an extra wee stab of the throttle when lifting the clutch and the engine will drop revs extremely fast when the clutch is in, meaning on spirited downshifts you really ought to make an effort towards rev-matching. There seems to be a nice middle-ground somewhere between the stock one and a super super light one.

truth. i have to rev-match a lazy upshift

[titian]

 kamineko']

[quote name='boon said:

Just don\'t get too carried away about making it light... the loss of mass and angular momentum means you have to give it an extra wee stab of the throttle when lifting the clutch and the engine will drop revs extremely fast when the clutch is in, meaning on spirited downshifts you really ought to make an effort towards rev-matching. There seems to be a nice middle-ground somewhere between the stock one and a super super light one.

/quote]

truth. i have to rev-match a lazy upshift

Ah the beauty of a light flywheel. Luv it! :D Get ya heel/toe weighed off, An ya Left foot brake downshift!

[lachlan]

i have a 4.5 kg one in the wrx . and a 4 ouk

yeah i stall im maybe 1 time in 5 times driving it . but its fkn amazing to drive , rev matches so awesom . on the up shift and down shift . un settles the car so much less than stock one