View Full Version : Lightened flywheels and uprated clutches
This car I bought the other day has an OS Giken clutch and a lightened flywheel, supplied and fitted by Whifbitz, I think. The clutch is a bit fierce for my tastes but I'll get used to it, however I don't think I can live with the lightened flywheel. It sounds awful to me and I'm already getting bored of explaining to folks that no the car isn't about to fall to bits (I hope)
So, what I want to know is can I use this OSG clutch with a stock flywheel? Or do you have to use the flywheel that is matched to the clutch?
Is there any reason that using a stock Toyota flywheel and a OSG clutch would be a bad idea?
Thanks
ps,
Paul Whiffin, if you see this thread, do you happen to remember what flywheel is fitted? I think Mike said it was also an OS Giken one. Thanks mate.
It is an all in one unit. see here:-
http://www.osgiken.co.uk/racingclutches.asp?do=model&modelid=7&manname=Toyota&modelname=Supra
It is an all in one unit. see here:-
http://www.osgiken.co.uk/racingclutches.asp?do=model&modelid=7&manname=Toyota&modelname=Supra
I'm slightly embarrassed to admit that I don't know what I'm looking at there Martin. I assume that you saying it's an all-in-one unit means that I can't use a stock flywheel, right?
Are all uprated clutches like that?
No only plated clutches are like that. THe OSG range (which we now stock cheaper then RRP (shamless plug)) are great clutches .
Do you not like it?
lol @ shamless.
You sure it isn't a sham?
Im afraid yor stuck with it unless you use a similar setup to mine or raise the idle to around 1K which is supposed to make it better.
The noise you are hearing is apparently the idle gear as its not getting any damping from the flywheel anymore it rattles.
Ive gone the lightened flywheel way before.. I managed 2 months and it was out..
Ive spoken to a few people running the RPS Carbon Carbon and they have reported a MUCH better result.. The noise is still there but no where near as loud or frequent.
No only plated clutches are like that.
Do you not like it?
I'm OK with the clutch itself, it's the flywheel rattle that I don't like.
So what are my options if I want a proper weight flywheel, replace the whole lot?
depends if its a push or pull clutch, mine only rattles when the clutch is pressed down, but its bloody loud.
i hope my new exedy clutch aint as bad:)
All OSG's are backwards I tell ya! But come with all teh hardware needed.
Have a TRD Twin Plate Clutch , rattles also a bit, but the HKS one rattles even more....
So what are my options if I want a proper weight flywheel, replace the whole of the OS Giken clutch?
Bummer :(
In that case I'll live with it for a while.
Might aswell wait till you can spank the arse of it a ware it out before you reaplace it. Get your moneys worth out of it ;) No-one can hear the rattle at 180!
Is the benefit of a lightened flywheel just weight saving or are there other benefits too?
It enables it to rev quicker
also loses interia on the gear change.
I hate the rattly FW's. People have a nice car, then they install a FW that sounds like a tractor in traffic. Been there, and wouldnt want it again.
also loses interia on the gear change.
Sorry to sound a numpty but what does that mean? :blink:
it loses engine inertia faster. The revs drop a lot faster between gear changes with a Lightened flywheel.
Inertia is a rotating body's tendancy to resist changes in speed, so a lightweight (low inertia) flywheel will (a) spin up more quickly and (b) lose revs more quickly. If you want to do fast gearchanges in a manual car the last thing you want is to be waiting for your engine revs to change.
What is sometimes overlooked is that a large clutch friction plate also acts as a kind of unintentional flywheel for the gearbox input shaft, which means that when changing gear the gearbox input shaft can still be rotating at a fair old lick, so when you bring the clutch back up it puts stress on the synchros.
Chris Wilson
02-06-06, 11:33
It's not the flywheel per se that rattles, it's the gearbox. The stock dual mass damps out gearbox harmonics, but weighs a ton. All aftermarket, none dual mass ones "cause" gearbox and geartrain noise.
As far as the clutch is concerned the Giken ones are very good, as is the quality of their flywheels. They aren't normally fierce, either, unless it's a triple plate?
you couldnīt hear my flywhel chatter could you Jake? i just raised the idle to around 1k rpm. i couldnt stand the sound either
Giken ones
aren't normally fierce, either, unless it's a triple plate?No, it's a dual plate one.
you couldnīt hear my flywhel chatter could you Jake? i just raised the idle to around 1k rpm. i couldnt stand the sound either I didn't notice any excessive rattling on yours mate. I'd be very happy if mine sounded like yours. My idle is already around 1000rpm though.
My RPS one rattles like a b'stard. Something I've just gotten used to I guess.
Chris Wilson
02-06-06, 13:06
If you really get bugged by it you could try a heavier weight oil in the gearbox.
No, it's a dual plate one.
I didn't notice any excessive rattling on yours mate. I'd be very happy if mine sounded like yours. My idle is already around 1000rpm though.
i think my idle is actually at 1100 rpm. May be worth giving it a try before you start replacing parts. i know youve got one of those complicated ECUīs but you should still be able to alter it by adjusting the throttle stop screw
Mine rattles too, it is irritating as you have this lurvely car that people look at and then you start it up and it sounds like somethings gonna drop off ! Then you stick your foot on the clutch and the clutch makes it's noises too :rolleyes:
Gaz Walker
03-06-06, 11:05
Mine rattles too, it is irritating as you have this lurvely car that people look at and then you start it up and it sounds like somethings gonna drop off ! Then you stick your foot on the clutch and the clutch makes it's noises too :rolleyes:
How you getting on with your clutch Matt?
Gaz.
Chris Wilson
03-06-06, 15:46
Mine rattles too, it is irritating as you have this lurvely car that people look at and then you start it up and it sounds like somethings gonna drop off ! Then you stick your foot on the clutch and the clutch makes it's noises too :rolleyes:
To a car savvy onlooker these noises will bring a nod of appreciation :)
How you getting on with your clutch Matt?
Gaz.
Getting used to it mate, so I'm gonna keep it. It'd be no good as a daily driver, but this car only comes out on sunny days ;)
To a car savvy onlooker these noises will bring a nod of appreciation :)
You're right, but they're a rare breed :)
It's not the flywheel per se that rattles, it's the gearbox. The stock dual mass damps out gearbox harmonics, but weighs a ton. All aftermarket, none dual mass ones "cause" gearbox and geartrain noise.
As the esteemed CW says, the standard dual mass flywheel is tuned to take all vibrations out of the crankshaft to gearbox power transfer path.
Inside the dual mass is a damping medium (usually silicone fluid) that seperates the two pieces of the flywheel. This allows limited 'slip' between the two parts of the flywheel before the end stops are reached, normally around +/- 20 degrees movement.
Without this the torsional vibrations in the crank are transmitted through to the gearbox, which hasn't been designed to use a solid flywheel. This sets up chattering in the gear set under no load.
There will be an rpm where this is not seen, probably a higher rpm than std idle where more power is required to spin the gears in neutral (the drag of the spinning gears & pumping the oil around).
Combine this with a heavier weight gear oil (the heavier the oil, the lower the rpm where the chattering stops) and with some experimenting it should be easily got rid of.
If the noise is bugging you that bad, then just switch the engine off when waiting at the lights, especially considering the cost of fuel these days or just crank up the stereo????????????????????:p
Can the damped oe flywheel be lightened as any kind of compromise?
Chris Wilson
03-06-06, 23:26
To all reasonable intents and purposes, no.
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