Lightened Flywheels

[MissR34]

Hey everyone.,

just wondering does any one have a lightened flywheel in their car, and did it make a difference/ what kind of difference did it make.

im trying to decide whether to get a lightened flywheel when i put a new clutch in or just to get my current flywheel machined.

thanks

[Eug]

yes, do it if you're changing your clutch. i'm kicking myself because i didnt.

never ever lighten your stock flywheel, it will shatter and most probably cut your legs off. they will lightly machine it to get the surface flat when you change your clutch though - which is totally fine.

a quick question though cara, why do you want to change it? are you going to be circuit racing? because that's really the only place you'll ever make use of it in high rpm. a lightened flywheel will reduce torque, getting off from traffic lights becomes a hassle, need to rev more to get going = more fuel, changing gears becomes a mission as the revs drop off too quickly, some gearboxes have been known to vibrate as flywheels supposedly absorb a fair bit of the engine's vibrations (unconfirmed), going up hills becomes an issue apparently too.

far too many negatives for your street applications to even consider it. have a long think about where you'd like to go with the car and plan your mods out accordingly.

any questions ask away, i've researched into it fairly extensively as i'll be putting one in when my new clutch goes (which wont really be anytime soon )

eug

[MissR34]

im changing my clutch cause ive burnt it a couple of times and im also doing the go to whoa at gazzants in oct and dont know whether it will survive LOL.

and was jsut thinking well if i do the clutch maybe do the flywheel as well

[unarmed_skyline]

hey cara,

This topic has come up a few times and i've read a few of the previous threads, i think from memory theres a few different weighted lighened flywheels, and each of which are suited to different styles of driving, i'm quite sure if you get the one which is only a little bit lighter than the stock one it will be benifitial to daily driving, as your car will have more accelaration, i think someone came up with some equation that like 1 kg rotational weight reduction is equivelent of 10kg of car weight (they arnt the correct figures but something like that), but you will loose some toqure, i also remember some people who said they have them didnt notice much if any of a difference on petral consumption although there were a few people who said the oppisite.

I think they are well worth the money if you research the right one for what you want to do.

i dont have one in my car, i was thinking about getting one when i burnt my clutch out but then i didnt have the cash to fork out at the time n i dont really think they are enough of a gain to warrent dropping the trans just for changing the flywheel.

[NA_R33]

DO IT!!, i havent done the flywheel but i just put an underdrive crank pulley on the 35 which works under the same principles as the lightened flywheel and OMG!!! the car is so much more responsive... a hell of alot quicker overall!! Downsides is it stalls a little easier but if u can put up with it (which isnt really that bad anyway) go for gold ull love it!! cant wait till i destroy the clutch so i can lighten mine... i have access to lathes so i will be lightening the stocko one...

[R34GTFOUR]

i dont know if its any use to you, but when i had a st162 celica i had a fair bit taken off the stock flywheel and i noticed a massive difference. Not so much the stalling problems but definately the torque disappearing. But it was definately much more responsive and rev happy and on a flat road it was alot quicker, but as soon as it was uphill it was slower.

Edited September 18, 2007 by R34GTFOUR

[scotty014]

yep that is true it says that before you buy the part on gran turismo 4 lol.

[Eug]

i have access to lathes so i will be lightening the stocko one...

shotgun not wheelchairing you around when you become handicapped dude.

[R34GTFOUR]

shotgun not wheelchairing you around when you become handicapped dude.

if its going in a stock n/a car i wouldnt be worried, but if its going onto a high reving big hp motor then i wouldnt go down that path...

[Eug]

we both do track work... so high loads and rpm goes without saying.

[scathing]

cant wait till i destroy the clutch so i can lighten mine... i have access to lathes so i will be lightening the stocko one...

I'd suggest against it. Lightweight flywheels are relatively cheap for our cars, and there's no way you can get it light enough on a lathe to be "perfect".

I've got a JUN flywheel in my Z33, and its about half the weight of the stock unit at 14lbs. Everyone was telling me the car was going to be a pig to drive, but after I installed it all I could think was "it could be lighter". When my clutch dies, I'm probably going to get a Tilton unit, coupled with their 7lbs flywheel.

The car the JUN flywheel came out of had the engine rebuilt to beyond Nismo S1 spec (lightweight forged internals to rev the VQ to 8000RPM, big cams, head work, etc) and in his car it was an issue. Unless you're going to build the engine to sacrifice all that low end, even halving the weight of the stock flywheel isn't enough. What's the likelihood that you can shave off 60-75% of the flywheel without putting your legs in danger?

This information doesn't apply directly to MissR34 since her car won't have the surfeit of low-end torque our cars do. But I'd say a lightweight flywheel is definitely worth doing if you've got everything in pieces anyway. If you don't drive the car in anger where that instant revvability is desired over the loss of low-end pulling power and inevitable rattle, just get a mildly lighter flywheel.

[skyla]

Now this is a subject I'm very interedsted in, as I've just brought a toda Light weight flywheel (4.4kg) for my R33 GTS25 (not yet installed). The reason I brought it is as I circuit race the car and find the car a little unresponsive when coming out of the corners, seems to take forever to get the heavy beast moving, I thought by installing a lighter flywheel that I might just be able to liven it up a bit.

Now reading this post I'm a little concerned that I might have gone too light with the flywheel as I still drive the car on the road. My car is already a little frustrating to drive at low speeds and in traffic thanks to a button clutch. Any idea how the button clutch/ lightweight flywheel combo will be like to drive on the road?

[djr81]

Read post number 59 in the following thread.

http://www.skylinesaustralia.com/forums/in...40&start=40

[MissR34]

the flywheel im looking at is a chrome moly flywheel and weighs 5.5kg, the stock flywheel is about 9 kg

[Eug]

flywheel (4.4kg)

I circuit race the car and find the car a little unresponsive when coming out of the corners,

Any idea how the button clutch/ lightweight flywheel combo will be like to drive on the road?

how much was the toda flywheel? and who'd you order it through? the lightest one i've seen (and frankly the only one i was interested in due to its weight) is the 4.8kg cusco. didn't know there even was a brand called toda

i'm pretty much in the same position as you, i also circuit race and find it quite lacking in punch coming out of corners.

no idea on a button/fly combo, but i'd expect to have jerky take offs and it might catch you off guard and stalling when you're being lazy.

by all means cara go for it if you're taking the clutch out, it saves dropping the gearbox again. but my personal opinion would be to go all out with the lightest and deal with the annoyance or none at all. if you're not racing or doing some form of motorsport than it's not really THAT necessary.

p.s. - i'm sure despite the initial awkwardness any driver with half a mind will quickly adapt and it will simply become normal after a few days/weeks

[MissR34]

there is another flywheel called the ultra light flywheel but they told me not to get that one cause it is too light

it is to go with a heavy duty organic clutch

[skyla]

how much was the toda flywheel? and who'd you order it through? the lightest one i've seen (and frankly the only one i was interested in due to its weight) is the 4.8kg cusco. didn't know there even was a brand called toda

I picked it up 2nd hand for $450, here's a link http://www.modyourcar.com.au/product_info....roducts_id=1430 with a bit of info on the new item, they advertise the flywheel as 4.8kg, I've weighed my one a couple of times and I got 4.4kg may be my scales are out???

Edited September 19, 2007 by skyla

[Eug]

is that NZD$450 second hand? equals to roughly AUD$400, which is pretty decent

that side has AUD$838.95 - which is far too expensive.

rough quote on a cusco 4.8kg is AUD$460 ($500 max?)

hmm... tempting

- drop gearbox, not to mention "hey why not do the clutch again".

- we're looking $1000-1200 :|

[skyla]

Yep in NZD. It will be a little while before the new flywheel goes into my car, but hope to have it in the car by early next year for a club track day, I hope to give a couple of the turbo boys a bit of a run for there money

Edited September 19, 2007 by skyla

[screamin']

That's the way Rach! I think the N/A team will put on a good showing

I need to weigh the TODA flywheel that's in my rallycar. It's full of holes and feels a little too light for the 2ltr. Hopefully the new engine build will fix that.

Funny thing tho, my road car (also RB20DE) eats the rallycar for breakfast under acceleration anywhere in the rev range and it still has the std flywheel.

Rach, before you put they flywheel in do some standing sprints (you still have a timer thingy right?) and some more after. Want to see how the numbers change.