Courtenay "billet Steel 5,6 Kg Flywheel"

Posted 25 June 2004 - 07:29 AM

Thought it seemed reasonably priced at £225 compared to the horrific £370 that AmD quoted me!! And the Courtenay wheel is a brand new item, while AmD just machine the standard one. And the court item is a mere 5,6 kg compared to the 7 kg AmD lump (because they use stronger steel) I immediately placed an order!! Are there any drawbacks

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Posted 25 June 2004 - 07:34 AM

I'm doing the same with my Turbo, AMD's price is horrendous and there's not a chance they'll get my business for a heavier flywheel, which is merely a modified standard one when I can get a billet fitted for only £150 more than AMD want for the parts alone.... From my dealings with Jon at Courtenay, the flywheel will make a significant difference to the tractability of the engine, free to rev and quicker pickup. You should like it, plus it's billet so it looks nice and shiny when you get it

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Posted 25 June 2004 - 07:52 AM

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Posted 25 June 2004 - 07:54 AM

Seems it is available for both - or fit both. Thought I should make some use of my unfortunate clam-off!! Yes, I also think it will make a nice difference. It is a family sedan engine at it feels like it. With better sound from my Milltek and a motorcycle-type rev pick-up I expect a lot racier feeling. Spoke to the Lotusspecials guy at Hockenheim and he complained that the 195 hp car was hard to drive on the track bacause of the heavy feel, the slow pick-up. This should help matters!

Edited by clipping_point, 25 June 2004 - 07:58 AM.

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Posted 25 June 2004 - 08:13 AM

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Posted 25 June 2004 - 08:48 AM

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Posted 25 June 2004 - 09:08 AM

Looks nice too!

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Posted 25 June 2004 - 09:15 AM

Looks nice too!

That's my point, you'll have something to look at for a while I'm getting mine done in July I think along with a charge cooler and an uprated clutch. Cuts down on labour for sure.

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Posted 25 June 2004 - 10:21 AM

I'm getting mine done in July I think along with a charge cooler and an uprated clutch. Cuts down on labour for sure.

Let me know how you get on Dave. I'm thinking of the same mods for mine

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Posted 25 June 2004 - 03:19 PM

I will be interested to hear how such light flywheel performs.... I hope it`s not too light!! cast-iron fw cannot be lightened too much or they might disintegrate under strain.... otoh, steel is virtually unbreakable. my tuner says that with charged/turbo engines, a fw too light might take driving ease and plasure off.... he just reinstalled the crankshaft, and it´s so weel balanced and lightened that when you spin it, it keeps going for several seconds on its bearings.....

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Posted 25 June 2004 - 03:27 PM

Lightened flywheel is one of the best things about the stage 3 IMO, it may be machined buts its machined by a TOCA car team so its pretty good Ricky has a point, one of the reasons I've been umming and ahhing whether to get one in the VXT is that turbos simetimes don't react well to them, all depends on weight, too little can be disastrous

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Posted 25 June 2004 - 04:39 PM

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Posted 25 June 2004 - 06:34 PM

The flywheel is still 5.6 kilos, about 7 years ago this was just under the norm for production road cars , its just that the power units are built and marketed world wide which has leed to such huge increase's in flywheel weight for emmisions etc (through lower than UK idle settings in various countries). Race cars have flywheels of 2.5-3 Kg, at this leval granted some drivabilty may be lost, not a problem, as they dont sit at cruise, however we have never expirienced this at 5.6 kilo's even in heavier cars like the Astra Coupe turbo, dont forget the press loved the light flywheel and its ability to rev in the sprint. I will bring along the billet and standard units on Sunday.

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Posted 26 June 2004 - 10:22 AM

Interesting thoughts indeed, and they confirm my choice. An extreme 3,2 kg aluminium RKSport flywheel is available at a price just over £100 but I preferred this product becuse of strength and drivability (without actually knowing if it was there are such limitations ) But if the same flywheel is used both in a great Chevrolet sedans and our small cars, then there is naturally an advatage to use a lighter one in this case

Edited by clipping_point, 26 June 2004 - 10:24 AM.

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Posted 26 June 2004 - 01:19 PM

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Posted 26 June 2004 - 09:55 PM

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Posted 27 June 2004 - 08:33 AM

Read this on the german site:

Advantages:
• Engine winds up faster
• More spontaneous responding
• Smaller mechanical load

Disadvantages:
• Jerky idle
• Torque loss with too small masses
• Losses at upward gradients faster at speed
• Transmissions and torsion bars of the clutch are more strongly stressed
• Does not keep speeds constant (changing resistances are more strongly felt)
• When switching gear too fast number of revolutions are lost in the engine.

i disagree with the disadvantages.

i have driven with a very light flywheels for 4 years in my kadett. 2.9kg (flywheel is 170mm overall and with a 150mm twinplate ap-clutch.

when shifting gear you have to do it quicker than with the std flywheel or the revs will fall too far.

no problem with jerky idle even with mean cams. steady 900rpm (jerky idle is not like a little rough in my mind )

you can never get a torqueloss/gain with changing of a flywheel.
you only change the deliverence of it (the heavy flywheel is just a way to smoothen the way you feel it)


the torsionstress of the gearbox will actually be less with a lighter flywheel.

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Posted 27 June 2004 - 08:40 AM

Yeah, I only wanted to reflect the arguments, I do not buy them

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Posted 27 June 2004 - 10:12 AM

Yeah, I only wanted to reflect the arguments, I do not buy them

i never thought you go for that recommendations either

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Posted 27 June 2004 - 05:30 PM

Got this answer as well on the german site (and I started the thread ): "Stephan": Die Courtneys Räder haben wir auch schon mal getestet. Sind zu filigran gearbeitet und verbiegen sich unter Hitzeeinwirkung. Die Aluräder sind stabiler ausgeführt, damit gibt keinerlei Probleme. Meaning: We have tested the Courtenay flywheel and found that they are too delicately machined, and will bend in heated conditions. The aluminium wheels are more stable, and give no problems (and better heat transfer I might add, am a materials engineer ) He also recommended that a Sinter Clutch Plate is installed, once the clam is off and the motor and gearbox are separated.

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