Lightening Flywheel

[**Ghost**]

Has anyone done the process of lightening the OEM flywheel by getting it machined? Is it reliable?

[bennjamin]

I havent myself- but i would advise AGAINST this provess. For a few reasons -

1. Price - for a similar price, you can get a NEW aftermarket flywheel.
2.Reliability- Honda made OEM flywheels exactly as they are for a reason , IF soem one was to remove material - possibly in the wrong place there may be a perpetual redundancy issue comign into play . IE not balanced properly.
3. With an aftermarket one, ofcurse after you can still reattach the OEM when u sell the car etc.

IMO , get an aftermarket and dont bother with machining a stock item !

[wynode]

Machine the stock flywheel incorrectly to reduce weight.......and it could BLOW UP!

[ProECU]

Comparing ITR vs Stock B flywheel, the type-R appears to be a lightened version of the stock B. The only aparent difference is the mass removal at the outer edge of the flywheel.
I cant see honda making a new cast for such a small item, so I assume they're machined lighter at the factory also. I dont know if they're hardened at all after the material removal process.

You should be fine machining the stock flywheel, just dont go crazy with it.
Make sure the shop balances it also. Should only cost you about $50-$80 to get done.

[wynode]

I think the issue is with the shop and if the shop doesn't rebalance it properly or takes the weight out of the the wrong place.....then you could have issues.

But I guess it has a lot to do with how much weight you want to loose off the stock flywheel and where exactly this weight is removed.

I'm just saying becareful because I've heard of lightened OEM flywheels that have blownup due to poor workmanship (this was a d-series flywheel)

[**Ghost**]

$50 - 80 bucks wont get me a new flywheel... now to find a experienced and well regarded machinest

[ProECU]

I think the issue is with the shop and if the shop doesn't rebalance it properly or takes the weight out of the the wrong place.....then you could have issues.

But I guess it has a lot to do with how much weight you want to loose off the stock flywheel and where exactly this weight is removed.

I'm just saying becareful because I've heard of lightened OEM flywheels that have blownup due to poor workmanship (this was a d-series flywheel)

Ya, exactly.
Material should only be removed at outer rim. This is where mass effects centrifical forces.
Make sure its balanced also, this could effect harmonic dampening and cause accelerated crank journal & bearing wear.

[mister]

have you a after market clutch already to match the flywheel?

[panda[cRx]]

on the subject... seeing as we get lightened flywheels due to the light weight being more inertia friendly in aceleration how light is too light? coz yeah they accelerate faster but they also decelerate faster and i've heard of people with ultra light flywheels having to rev their car at the lights to it doesnt stall.
like has anyone experienced this with the toda B-series 4.1kg Flywheel?

[z3lda]

with b16. the lighter-er-er-er the flywheel the more torque u will lose. so dont get one tooooo light. spoon 3.9/toda 4.1 is ok. any lighter ur torqueless machine is be "HAHA"

[wlee2]

i remember there was a post similar to this.. i thought it had to do with inertia rather than loosing Torque.. . i dunno about loosing torque as its difined as the force of rotation or something like that.. i dunno i didnt do engineering.. but i dunno about loosing torque.. and remember gary if the machined flywheel blows your NUTZ are in the firing line!!!.. metal shrapnel can pierce throught anything =P.... bwhahahahha.. (i dunno if its true or not)

[mister]

yes make sure it is done by professional engineer, otherwise they may not take great care, just to get your money.
it will rev faster, but will lose torque especially up hill.

[panda[cRx]]

with b16. the lighter-er-er-er the flywheel the more torque u will lose

why is this?

[bennjamin]

with b16. the lighter-er-er-er the flywheel the more torque u will lose. so dont get one tooooo light. spoon 3.9/toda 4.1 is ok. any lighter ur torqueless machine is be "HAHA"


fill us in....


my guess for today is that a car never "looses" ( or gains) torque via a lightweight flywheel - its just one point in which the applied directly from the crank energy is stored....lighter, less energy is stored and thus will reduce both action and reaction time.

[J_Mech]

The flywheel is basically only there to reduce the speed fluctuations and provide a smoother feel of power flow especially during idle. This is because the torque from the engine is not smooth there are indivdual torque pulses from the individual cylinder firing, the more cylinders you have the smoother the torque flow is.

If Honda doesnt use the flywheel as a dynamic balancing component to balance the dynamic forces from the engine components, then its fine to reduce the mass/inertia of the flywheel without engine balance going out the window. It might feel rougher during idle (more speed fluctuations), and might be easier to stall (as the motor will be less imune to big clutch drops during take off - require more rpm matching) but will improve acceleration as less torque is used to accelerate the flywheel.

J_Mech

[alphabeatsco]

duynno who's talking real here.
i've heard many saying it will lose torque..and many saying it wont lose torque...
im actually in the situation where i wanna do it..but dunno if it's a good idea..

[ProECU]

torque is a product of rpm & power. A flywheel can not effect the torque production of a motor.

Does it effect the power put to the wheels? Im not sure.

Personally, I run a lightened stocky f/wheel. It's not that much of a noticeable difference. Dont know if I would bother next time

[alphabeatsco]

is it neccesary to change clutch with L/flywheel?

[tegstar83]

with b16. the lighter-er-er-er the flywheel the more torque u will lose. so dont get one tooooo light. spoon 3.9/toda 4.1 is ok. any lighter ur torqueless machine is be "HAHA"

U know what?? Dont post rubbish if u dont know what ur talking about!

Thats bullshit u wont loose any torque as torque is produced by the engine.
U will loose flywheel momentum going up the hill because of less weight and thus the amount of weight relates to keeping inertia going. Less weight= less inertia.

[alphabeatsco]

so wat flywheel is good? in terms of brand..also need clutch replaced together?

[mister]

so wat flywheel is good? in terms of brand..also need clutch replaced together?

yes better to get matched heavy duty clutch and lightened flywheel together. also saves money on installing labour.

[z3lda]

'technically' u dont lose torque power. a lighten flywheel does put more power from the engine to the ground but as i said if u get one tooooo light it wont be good for your launches. you will bog up.

[hoonda]

My b series flywheel is slightly machined- and yes it is profesionally matched to a heavy duty clutch.

i really dont notice much difference. if your getting a new clutch plate, then might be worth machining flywheel, otherwise prob not worth it IMO

[bennjamin]

My b series flywheel is slightly machined- and yes it is profesionally matched to a heavy duty clutch.

i really dont notice much difference. if your getting a new clutch plate, then might be worth machining flywheel, otherwise prob not worth it IMO

For those that have had their OEM flywheel machined....by how much did the weight get reduced ? I am thinking it is very significant compared to an aftermarket flywheel ( say OEM = 12kg , machined = 7 or 8 and aftermarket = 4 or 5kg ) . . . .anyone know the exact weight in comparison to OEM , aftermarket etc ?

[wynode]

'technically' u dont lose torque power. a lighten flywheel does put more power from the engine to the ground but as i said if u get one tooooo light it wont be good for your launches. you will bog up.
I think you've lost the plot.

A lightened flywheel will improve your acceleration / engine response but won't affect how much power you put down to the ground.

Launches will be a bit harder purely because there is less inertia with a lighter flywheel (not because there is 'less' power).

[wynode]

FYI



Regarding losing torque... No, you can't lose torque...
What is lost is inertia, it is the inertia of the flywheel that keeps you motoring up a hill on the freeway without pushing the accelerator more...
It is this same inertia that prevents you from achieving maximum acceleration.
This same inertia gives a very smooth idle...
I think you'll find, most people who don't like lightweight flywheels, actually don't like fast cars & certainly don't enjoy sports driving... LOL
Cheers

Adrian

Source (http://www.ozhonda.com/forum/showpost.php?p=164104&postcount=13)

[wlee2]

cool wyn that was the post i was refering to before but i couldent find it =P...

[wynode]

cool wyn that was the post i was refering to before but i couldent find it =P...
I vaguely remember Adrian posting that up so just searched posts made by him which had 'flywheel' in it :)

[Choongas]

I've put in an Exedy lightened flywheel (heavy duty clutch as well), it's about 4kg. It does make a difference. Especially through the twisties, it's so much more fun!

I'd say acceleration also increased a little, not much.

[bennjamin]

I've put in an Exedy lightened flywheel (heavy duty clutch as well), it's about 4kg. It does make a difference. Especially through the twisties, it's so much more fun!

I'd say acceleration also increased a little, not much.

Exedy ....for which engine ? D series or b series ? Where did u get it from ?!? PM me plz....


*back on topic*

[forensics]

just out of curiousity.. how much does a lighten flywheel roughly cost? iven been getting prices from 350 - 600... im after one atm

wanting to spend about 300-400 in syd. id order one from the dealers in the dealers section but i dont want to wait the 3 weeks for delivery

[ian]

is it neccesary to change clutch with L/flywheel?

I'd like to ask this question but in reverse:

"is it neccesary to change the stock flywheel with a new heavy duty clutch?"

..............with the aim of improving performance (not just weight reduction).

I have been advised by one clutch specialist that a light weight flywheel will not last as long as the oem item because it is not as thick and heavy. He also added that he's had many customers that have come in and said that their clutch is gone, but upon his inspection, it was the the light weight flywheel that had failed ie warped, broken etc. He recommended that an upgraded heavy duty clutch will make the difference and that the only difference on a light weight flywheel will make is the actual weight itself = reduce overall weight.

Is this 100% true?

Can anyone shed some light on either and/or both these questions. :thumbsup:

[wynode]

Flywheel doesn't waste as much as a clucth.

Get a good quality flywheel and you'll enjoy the benefits!

[SPEEDCORE]

it was the the light weight flywheel that had failed ie warped, broken etc.

The problem I see here is that in general terms people who get a lightweight FW get an aggressive clutch and still continue to ride their clutch. Considering that it is thinner (not the only way weight is saved, material removed from the outer edges of the FW), the heat build up of riding the clutch is much more pronounced as.... well.... to put it simply.... there is less material to store heat.

This in turn is what can lead to destroyed lightened flywheels with scoremarks, pitting and like you stated warping. I would be pointing my finger at aggressive clutches with inappropriate use destroying LW FW first before blaming the actual metals used.

[ian]

ahhh, i see speedcore.............hmmmmm, so a well balanced clutch/flywheel combined with a well balanced driver/user = better performance than stock.

[bennjamin]

ahhh, i see speedcore.............hmmmmm, so a well balanced clutch/flywheel combined with a well balanced driver/user = better performance than stock.

that goes with all cars whether modded or stock methinks :)
And - better driver = better performance = hopefully better longevity :thumbsup:

[ian]

i hear ya ben............i second that.

[tegstar83]

I think it may be a waste of time removing weight from the stock FW instead just buy a toda or simillar

[wynode]

I think it may be a waste of time removing weight from the stock FW instead just buy a toda or simillar
The argument is that removing weight from the stock FW is cost effective but ONLY if it is removed from the correct part of the flywheel and balanced properly. You can reduce a few KGs but anything more you would have to make sure you have a good machinist.

If you are serious about it, just get a good quality lightened flywheel which has been designed from scratch to tolerate the forces applied to it by the engine and clutch instead of re-manufacturing a stock item which was designed with a certain weight and weight distribution to match its application.

[**Ghost**]

true... i had the opportunity to talked to a metalworker since i started this thread a way back... the machinest was not a typical automotive mechanic, he is more of a metal fabricator that does all things metal

he said he been asked to do it a few times by ppl but has always recommended against the whole idea.. just so u guys know he said typical flywheels (OEM) are cast items not forged... i didnt really understand wot he was going on about but something along the lines of

1. normal OEM flywheels are not forged and made of materials that are less structurally strong than aftermarket ones

2, u can balance and lighten the oem ones, BUT because its cast, not forged there are inherent "stress lines" inside each item, small imperfections that are inevitable in the process

3. if the item was forged this would not have been a problem

4, if the item was left stock it is fine because apparently the final casting process tothe flywheel "seals" the stress lines inside the item

5. so if u grind of bits of it, even if u balance it, u reveal the stress lines

6. so depending on the quality of ur OEM item its gonna crack if u lighten it

7., in conclusion its not a cool thing to do

[bennjamin]

The argument is that removing weight from the stock FW is cost effective but ONLY if it is removed from the correct part of the flywheel and balanced properly. You can reduce a few KGs but anything more you would have to make sure you have a good machinist.

If you are serious about it, just get a good quality lightened flywheel which has been designed from scratch to tolerate the forces applied to it by the engine and clutch instead of re-manufacturing a stock item which was designed with a certain weight and weight distribution to match its application.

to add...

a STOCK flywheel most probably cannot be safetly reduced in weight to that of a aftermarket flywheel. For one thing , aftermarket flyhweels often use lighter alloy materials that for the same density as OEM will weigh less in the first place. Maybe a coupel of kg/s off the outside of the wheel - but i doubt anything else could be taken off without severely compromisng longevity/saftey.

Get it done right , the first time :) 9-12kg OEM....7 or 8kg machined...or 4 or 5 aftermarket ? :D

[pornstar]

to add...

a STOCK flywheel most probably cannot be safetly reduced in weight to that of a aftermarket flywheel. For one thing , aftermarket flyhweels often use lighter alloy materials that for the same density as OEM will weigh less in the first place. Maybe a coupel of kg/s off the outside of the wheel - but i doubt anything else could be taken off without severely compromisng longevity/saftey.

Get it done right , the first time :) 9-12kg OEM....7 or 8kg machined...or 4 or 5 aftermarket ? :D

best check those weights

[bennjamin]

best check those weights

*checks* *looks at guesstimations+ questionmark* *waits for Pornstars correct input* :thumbsup:

[SiR JDM]

ITR Flywheel - ~6.8 kg

b16/b18 - ~8.8 kg

k20 - ~5.3kg

Im just requoting these from research ive done.. so if they're incorrect dont shoot the msger so to speak