im about to fit a api uprated cluth to my 390bhp 365 2.0 wrx is it worth fitting a lighten fly wheel or use a skimed recon which has come from for a very good company what would i gain and what woudl i lose form fitting a nice lighten fly wheel oh and im soon to be fitting a nice harvey smith up pipe to my car as well your thoughs please and technical advise cheers

 

pros - revs rise quicker as a lighter wheel is easier to spin
con's - revs drop quicker as there is less inertia as there is less weight.

If you think of the rotating mass of a 12kg classic flywheel (not static weight) then you are saving a huge amount of weight. Harvey Smith foes a 6kg flywheel - but this may give a little judder. API do a skimmed 7-8kg flywheel which will not judder (that is my experience from both). But do not go under 6kg if for road use

 

5 kilo super lightweight RCM flywheel here - works ok, but a lot of the rest of the engine is light too - billet crank, forged bits, lightweight pulleys etc so maybe makes it still useable

 

Definately plan for a skim whatever you do. I have the Exedy Lightened flywheel with the Exedy clutch and I do get a little bit of judder to say the least!

 

ive got a skimed fly wheel form subaru 4 you to put on a reconed one but i was thinking about getting one form api where they have lighten and balanced a suabru fly wheel just wondering if it is worth it will i notice any gains really and what about lossing the tourqe or is that myth my enigne is forged alright but i dont have the light weight pullys yet as im sure if doing these things are worth it or is it i now it looks nice : >

 

Run a forged 4.3kg flywheel here on the road and really like it.

The reason some suppliers stick to 7-8kgs is that you can't take any more weight out of the OEM flywheel without making it too weak and brittle. Aftermarket flywheels don't have this problem.

Lightweight pulleys are also worthwhile, the crank pulley being of most benefit.

https://www.scoobynet.com/trader-ann...k-pulleys.html

 

Hi Bob, have you any lightened flywheels in stock for a 5 speed impreza?

 

Harvey Smith does a cracking flywheel for road or track use. ACT 6kg or a 4.3kg - i think?

 

Yes mate :Clutches and Lightweight Flywheels - Subaru Impreza