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A lightweight flywheel is a good move.

Accelleration is improved full stop.

Torque decrease ----- false. Absolute rubbish!!!

Can't go up hills as quick ---- false. as above.

As a reccomendation go get a Ogrua lightweight flywheel or something similar they weigh 4.8kgs, the drivabillity is very good for the street with stock like characteristics.

Do not lighten the factory unit. Cast iron only has strength in the outer skin. If you take enough material out you drastically weaken the unit. There are plenty of cases of these sort of flywheels exploding and causing damage and injury. There are also plenty of people going around with them who haven't had one let go but, when you consider the aftermarket ones are much lighter still and being chromemolly will never 'explode', for $500 who would argue with that.

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I think the less torque theory comes from Gran Turismo :P

That 'simulation' game? :) hehehe

I was thinking about it a bit more tonite. How can it lose torque? You pull the engine out its still got the same amout. At the wheels it might make a difference, but after driving round tonite thinking about it, I dont think it does hey. And just listening to the rev speed of my car to other rb20s I think it makes a fair difference. BTW I have a JUN lightweight wheel in mine.

Chromoly won't explode but heavy-ass clutches and indiscriminant use can 'burn' straight through them.  Food for thought.

Adrian

i also heard the same adrian stop me from getting one when i replace my clutch didnt like the idea of destoring it

i have one in my daily driver

went from a 13.4kg stocker to a 4.5kg lightened one, that has most of the weight on the inside and very little on the outside

this one infact VV

FMZ004LC.JPG

its alot better IMO, i have no problems using it for driving in heavy traffic, i consider it to be an all round improvement. only different is you need to slip the clutch a tiny bit more to engage it at low speeds, and that it will punish you more if you make a bad gearchange. but really at the end of the day you will be a better driver for having one and it improves the cars revability and acceleration, not by a huge amount but a definate improvement. took me about 4 days to get used to and since then i havent looked back

People that have driven my car with the lighter flywheel always commented how it rev'd a lot easier.

this was before i did all my mods and it was making ~185-200rwkw like most melb R33's depending on your dyno choice.

Chromoly won't explode but heavy-ass clutches and indiscriminant use can 'burn' straight through them.  Food for thought.

Adrian

I think you got mixed up there.

The metal used in the construction of the aftermarket flywheels is harder than cast iron. It is in fact the lightened cast iron flywheels with no hard outer skin left that get eaten through, that is why they explode and the chromemolly ones don't . All triple and quadruple plate clutch systems designed for mega horsepower utilise chromemolly flywheels as a part of the package not cast iron. Cast iron flywheels require 'skimming' when replacing even organic based factory clutchs. 'Chromemolly steel' never requires this. Some really good flywheel packages are even gas nitrided on the friction surface.

Well guys I bought the light weight flywheel from UAS today, and had a chat to John as always... They're real helpful over there I tell ya!

This one weighs in at 4.8kg.

Anyway, here are some photo's that I took of it. It'll be installed tomorrow with the daikin heavy duty clutch.

537_flywheel4.jpg

click thumbnails to open the photo in a larger window

th_cc0_flywheel3.jpg th_50d_flywheel1.jpg th_43f_flywheel2.jpg

I'll know the results tomorrow.... (fingers crossed ay)

wil..

Clutch and flywheel are in.

Torque loss - None that I can really feel. The car however picks up a lot nicer than it use to. It runs through the rev's significantly faster than before.

The clutch is rated as having a higher clamping force than before, yet the pedal feels "lighter" than it use to??? What's the go there.

The new clutch grabs a lot harder than the old. That much I'm sure of. But I'm just curious as to why the pedal feels lighter? I always heard that replacement clutches with higher clamping loads would be heavier in feel.

Clutch and flywheel are in.

Torque loss - None that I can really feel. The car however picks up a lot nicer than it use to. It runs through the rev's significantly faster than before.

The clutch is rated as having a higher clamping force than before, yet the pedal feels "lighter" than it use to??? What's the go there.

The new clutch grabs a lot harder than the old. That much I'm sure of. But I'm just curious as to why the pedal feels lighter? I always heard that replacement clutches with higher clamping loads would be heavier in feel.

The extra clamping force is offset by changes in the diaphram pivot point - so the clutch feels lighter but you need more clutch travel to disengage.

I had a molly lightened flywheel on my RB20DET, not quite as nice looking as yours though. :D

It is true that it needs more rev's to get off the line but I did find it accelerated quicker.

It felt as the torque made from the motor wasn't absorbed in the heavy flywheel before accelerating the car, instead more of the torque generated by the motor was able to filter through to the rear wheels quicker and easier accelerating the car quicker.

It also felt as if it didn't bog down as much, boost felt a little more snappy.. :)

It was a nice little mod. :(

i got a 2.5kg lightened fly for my car worth $900 apparently... just waiting for the work to finish b4 i can test it out

Hmm you sure it weights 2.5kg??? If so it must be made of carbon kevlar or some other exotic material?

I have 4.8kg chromemolly and the engine revs upto redline alot quicker and i dont see any negative effects with one

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