m_nettleship

3.0 Duratec, currently uses the dm flywheel, but decided gonna do away with this, and go 4 a fidanza lighter flywheel. as far as i can think, will it just let it rev faster, and give me more power lower down the band. With a little more torque but no more bhp.

Any views well apprciated!

burnzy

well cos it's lighter it reduses the un-sprung wieght resultin in your engine spinning up quicker even though it doesn't give u extra horsepower at the crank it should at the wheel's cos it'll reduce the drag improve braking and engine braking, cos it not havin to stop a heavy lump of metal spinning aswell as all the engine internal's n so on, exactly the same as light brake rotor's and wheel's ... Rule of thumb wieght is a killer of fun n speed, so my advice is go ahead with it you should notice a nice improvment

mechanic28

iTrader: (5)

would it bugger up its idle etc?

westus1

iTrader: (6)

all realy depends on how much lighter
but if done by fidanza i'd imagine it should be ok
if its done a bit homemade then it could be taken down to far and give rough idle

mechanic28

iTrader: (5)

true!mind you the d/m flywheels are not half shit lol!

-beefy-

iTrader: (6)

shouldnt bugger up the idle because you only reducking the wight of the fly , the revs etc will not increase as the revs are still controlled by the fuel and ignition etc ,


and if i was you fella, if fuck off the fidanza flywheel and speak to doug ( aka garage 19 )


i know i can cnc billet alloy flywheels of great quality ( im having one ) and i bet they dont cost as much as i fidanza jobbie,


beef

juffer

I thought the advantages of a lighter flywheel was to help the engine rev and have less drag. But surely on the down side when you go up a slope or hill it will reduce momentum and ruduce power. Just a thought and probably wrong lol

OldDan

Lighter flywheel will make the idle more lumpy.

burnzy

Hmm! good question i'm not sure i'v never fitted one personally, it wouldn't be drastic otherwise it wouldn't be a readily available mod n the only thing i can see it doing is raising the idle cos your engine doesn't struggle as much to pull it round at low speed, resulting in just turning down your idle, your not messin with the fueling or nothink so the mixture wouldn't change, maybe if there was already a problem like u had low compression on one cylinder it would prob's show up worse cos of the lack of unsprung wieght keeping the idle steady

burnzy

n that's sort of true but u would also be in the wrong gear n puttin your engine under stress if your car is seeming to struggle to go up a hill just change down n take the strain off the engine n gearbox then your light flywheel will come back into play

westus1

iTrader: (6)

the fuel/air and ign etc make the car rev
the flywheel provides the rotating motion/inertia to keep the engine rotating smoothly
if its to light or out of balance it makes idle lumpy
its not usualy noticed at higher revs as it tries to balance itself out when rorating faster

-beefy-

iTrader: (6)

fair enugh bud ,

saying that every application ive seen with a lightweight fly wheel usually has had the full bottom end balanced ,

surely that would then counter the poor idle as everything will be equal?

i wouldnt put a lighweight fly on any car that hasnt been built and balanced to suit ,


beef

westus1

iTrader: (6)

beefy
again if its to light then yes it will have poor idle
but they're usualy still heavy enough to not cause any probs

as a rough guide you can weigh your crank, rods etc
for every kg it is x3 when rotating so that gives a small idea of how light it would need to be to cause a prob

-beefy-

iTrader: (6)

ahh right , good info fella,

think standard cossie crank is 13 lb or kg ,

and dougs are 6 ,

so should be well within whats needed

beef

Garage19

Not sure how you figured that out?

A lightened flywheel will increase your acceleration with the results more noticeable in the lower gears.

A stock YB flywheel weighs nearly 10kg and has been designed to allow a smooth pull away of a 1270 kg car fully loaded with five occupants and their luggage.

A YB engine in a stripped out fast road or track car with two occupants max will require far less inertia from its flywheel for a smooth pull away.

Unfortunately, if you still have the stock flywheel you are wasting energy on accelerating that mass rather than accelerating your car.

If you want a lightened flywheel I would advise one that has been designed and manufactured that way. Lightning cast flywheels can be dangerous. They can make a real mess of your legs when they burst through the trans tunnel at 8000rpm.

foreigneRS

this thread is a good example to not believing everything you read on the internet

james kiely

iTrader: (5)

doug does the whole of the engine need to be balanced to see any gains out of a lightened flywheel,
cheers james

Garage19

Not at all.

Ginge !

did you get my PM too pmsl

pa_sjo

Wat?! You mean it's not ALL true?!

Garage19

Yes, need some piccies of what you are after.

pani_k

iTrader: (1)

As said above less rotational inertia and easier to spin up thus first and second gear pull away should be better but less noticeable in higher gears. Downside of having less rotational inertia is that it is going to be easier to stall if you don't get the biting point right and give it enough beans and up hills it will struggle a bit more.

m_nettleship

i see, So do i see more power lower down the revs then?

richard_syko

Effectively more torque at the wheels because less engine torque is being used to accelerate the flywheel.

The engine will still make the same power and torque.

m_nettleship

i no it will produce the same power, but will i see my power curve rise earlier?