Lightened flywheel. Update: how light and where to get it made?

[Ashh]

After some sanity-checking/opinions.

Through the powers of second-hand buying I'm shortly going to be in possession of a lightened 3TGTE flywheel (taken from 8 stock, I think, down to just over 6kg). Now I've heard that you shouldn't lighten the stock cast wheels for fear that they'll explode?

With that in mind, should I build a scatter shield/buy a ballistics blanket (something I just learnt about from NME308's build)?
If so - which one?

Info:
Turbo 2T/3T build. Probably won't be altering the redline (so keeping it at 6500, maybe going to 6900 now that I've got better valve springs).

It's going to have an exedy button clutch clamping onto it.

Cheers for any input

[NME308]

Hi Ashh,
Doug from NPC was extremely concerned at the prospect of me using a STOCK unmachined flywheel with a proposed 500hp and 7000rpm max.

I have personally witnessed a 55 chev sedan have a chassis rail blown in half and large holes busted through the firewall and bonnet from a stock flywheel exploding without scatter shield or blanked for protection. The driver only ended up with shrapnel in his leg but it could have been far worse.

Long and short is some motorsport governing bodies mandate scatter shields or blankets for any lightened stock flywheel regardless of increased engine performance as a safety measure. You may never explode a flywheel but the chance is always there. A quick youtube search will show some of the nasty results...

Think carefully about what you are going to do and good luck!

Cheers,
Jason

[CrUZida]

Personally I'd never use a lightened or modified stock flywheel. The risks far outweigh the cost savings.
An off the shelf aftermarket light flywheel is usually around the $500-$600 mark (give or take).
Just bite the bullet and do that bit properly.

[Ashh]

Hmm... This is not good news.

I'd happily pay 500-600 dollars for an aftermarket one (for a 3tgte as I now have a bigger clutch) but have no idea where to get one/if they even exist.

Are there any good places to buy ballistics blankets?
How thick is a scatter shield usually? 6-8mm steel?

[Ashh]

Found that fidanza makes a flywheel, except that it only weighs 4kg!! I think that's a bit ridiculous...
Are there any intermediate flywheels?

[NME308]

Hey Ashh there are a number of clutch companies who can machine you a billet flywheel to suit your application. I have used NPC Clutch who have been great to deal with and I am sure there are others probably closer to you too.

It might be worth making a phone call or two and finding out what sort of dollars it would cost for a locally made flywheel made to suit. On the Fidanza wheel I cannot quickly find specs of what clutch size it accepts etc...

Cheers,
Jason

[xero]

4.4kg actually (according to their 2014 catalogue) and its a steel flywheel with replaceable plates.

ok so google tells me:
this one is 4.9kg (dunno what they are on about with the starter ring gear though)
http://www.blingfactory.fi/epages/vi...ducts/BF202003

this one is also 4.9kg
https://products.vividracing.com/aas...4383484992.php

[ctrain]

i thought lightned flywheels were no good for turbo applications as the extra weight helps the turbo somehow?

[oldcorollas]

if the machining is outside the loaded area, ie pressure plate bolts, then probably not as big an issue..
but taking away material between centre and pressure plate bolts will affect strength (even if negligibly)

replaceable centre is a nice thing.

I have a 4K flywheel that is 2.8kg (chromoly)

[ToyTA22]

Ash. I have a brand new fidanza alloy flywheel with removable face for a 3tgte and Exedy clutch to suit. I will be using for my 3t/2t engine later. The clutch is 225mm dia where as 2t is 200mm. I bought flywheel from US about 3 years ago when dollar was better for $365aud on my doorstep. Excedy clutch here in Aus for, I think $235. If you want I will try to find sales details on flywheel, I have moved house twice since purchase. I can find info off clutch and flywheel for you, but not till friday.

[jondee86]

Sigh... so much myth and legend on this topic... so little science

Have a read of this....
http://www.roadraceengineering.com/c...ywheeltech.htm

If the people doing the lightening know what they are doing, you don't have a problem. But if some cowboy with a lathe cuts material out of a critical area, he may well shorten your life. This is one job you need to entrust to an experienced machinist who knows how much to cut, and where to cut it from.

Cheers... jondee86

[NME308]

Sigh... so much myth and legend on this topic... so little science

Have a read of this....
http://www.roadraceengineering.com/c...ywheeltech.htm

Well that was 5 minutes of my life wasted.
Advertising is indeed a science but only concerned with convincing a fool to part with their money...

Cheers,
Jason

[lexsmaz]

To answer your Question about the flywheel ring gear you put a link to is that the ring gear is the toothed outer ring that the starter motor runs on & on a manual flywheel its a separate part to the flywheel & they apparently will swap it over with your old one, ( only worth doing though if your old one is in really good condition, but you can get someone local to heat up your old one to remove & refit it ) ..

As has been mentioned the flywheel lightening could have been done badly, it needs to be a smooth finish & with no sharp edges or under cuts from the machining too & there needs to be a radius finish at the perimeter of the cuts too ..

Sounds like you are now going to use a New flywheel which is really the best way as the scatter shield might save you if the flywheel lets go, but the Exploding Flywheel will definitely take out / destroy the gear box bell housing & clutch & even possibly the gearbox & at worst the back of the motor too, the idea of the scatter shield is for it to be used only when everything else is spot on & nothing else can be done to make things better / stronger, not as a compromise for dodgy bits, because as I mentioned it just would not make sense to use a possibly compromised part as it could turn out to be Very Very expensive in the long Run ..

[allencr]

It's got nothing to do with whether it has been machined or the quality of the machining, It's FUCKING CAST IRON that's going to be used & abused more then a daily driver!

[jondee86]

Holy crap Batman... it's a factory lightened 4AGE Blacktop flywheel !!!! Quick Robin... to the Batcave... the world is about to be destroyed by exploding Toyota Corollas !!!!



Perhaps all the folk who cringe at the mere mention of a lightened flywheel, should write to the Toyota factory engineers and tell them that they don't know shit about flywheels

Cheers... jondee86