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Lightened Flywheels
Posted: Mon Mar 02, 2009 7:50 pm
by BigBavarian
Time for another if anyone is interested.
Hi, we have a contact who can produce for us some lightweight flywheels for the M20 6 cylinder engines, M40 and M42 4 cylinder 8 and 16 valve engines.
Can also do the s14, m50 and m52 engines and others if required!
The standard M20 flywheel weighs in at a mighty 8kgs+.
These ones weigh in at 4.9kgs for standard clutch or 4kgs for race paddle clutch. Billet steel, one piece flywheel, teeth cut into flywheel. No differing metals so no expansion contracting problems with different metals heating at different rates and cooling at different rates.
The technical stuff says that releases up to 60hp to the wheels from the engine, obvously a decreasing curve as you go up the gears but no loss of power just more released to the wheels from the engine.
Will not effect the idle of the engine.
Obviously the more we buy the cheaper they are.
Would anyone be interested? The difference in your cars peformance is outstanding! Best price is for 10 as they are made in batches of 10.
Looking at approx £230 each if 10 ordered, £270-00 each for 5.
Will get the technical stuff out if anyone wants to see it.
I have a M20 one fitted to my M50b2.5 and you can really feel the difference.
Re: Lightened Flywheels
Posted: Thu Mar 05, 2009 8:17 pm
by shorty73
Not yet fitted mine (race one) but can vouch for the quality.
Free Bump!

Re: Lightened Flywheels
Posted: Sat Mar 07, 2009 8:58 pm
by jaistanley
I too can vouch for them.. I've seen a few of these flywheels and they are extremely well machined. I've recently seen one specced/fitted to an S50B30 and the thing revs up like a bike engine!
but what are the downsides?
Posted: Sun Mar 08, 2009 6:37 pm
by dph500
I a interestd, but what are the downsides? There must be some, or BMW would not fit the heavier ones. Mine would be for a track day car. cheers
Re: but what are the downsides?
Posted: Mon Mar 09, 2009 1:47 am
by jaistanley
Basically you loose a certain ammount of 'everyday' driveability with light fywheels. The engine has less inertia so you could find yourself juddery on the clutch at first, trickling around in traffic can require a little more thought/clutch and throttle control and at idle you may get slightly more vibration and layshaft chatter from the gearbox (in neutral). I could bore you with science here but manufacturers fit heavier flywheels to smoothen response (less dynamic) and sort out NVH problems in drivelines/engines.
In practice on our larger 6 pot, silky smoothe and well engineered engines none of the above are true. I've driven several cars with light flywheels and ALWAYS thought it has been an improvement. The ones that BBB are offering are exremely well engineered and lack some of the down-side of the aluminium variety (it's made of one material for the main thing!).
HTH
Re: but what are the downsides?
Posted: Mon Mar 09, 2009 1:49 am
by jaistanley
PS, you CAN double declutch and heel and toe can't you? (If not, go learn noobie - lol). A nice light flywheel makes this a joy and quicker.
Re: but what are the downsides?
Posted: Mon Mar 09, 2009 1:53 am
by Jhonno
Heavier ones were fitted to help idle, no gearbox chatter, smoother drive (to allow for numpties that don't have a clue)
I have driven a variety of cars with lighter flywheels and always found it better, in fact I hate driving cars with standard flywheels now, they seem so dead and slow to respond
Re: but what are the downsides?
Posted: Tue Mar 17, 2009 9:25 am
by mccarthy
any pics?
Re: but what are the downsides?
Posted: Tue Mar 17, 2009 5:23 pm
by BigBavarian
i will get some up
Re: but what are the downsides?
Posted: Wed Mar 18, 2009 1:37 pm
by mccarthy
just bought one of these from the sale section and was wondering if a Torsion damper Clutch Disc was a necessity?
Re: but what are the downsides?
Posted: Fri Mar 20, 2009 1:13 am
by N00b
dph500 wrote:I a interestd, but what are the downsides? There must be some, or BMW would not fit the heavier ones. Mine would be for a track day car. cheers
Easier to stall. Idle more lumpy. Car feels more "raw".
Re: but what are the downsides?
Posted: Sat Mar 21, 2009 7:48 pm
by Dave_M3
God, I'd love one or two of these for the my iS'.
funds just aren't there at the moment though
Maybe i some other time
Another reason why orginial flywheels are heavy is that cast iron ones are far cheaper to manufacture than lighter billet steel items.
Re: but what are the downsides?
Posted: Sun Mar 22, 2009 1:46 am
by tg318is
hey would you ship 2 flywheels to Sydney, Australia? if so how much would it cost?
cheers
Re: but what are the downsides?
Posted: Sun Mar 22, 2009 10:47 am
by BigBavarian
i will look into shipping for you and let you know
Posted: Mon Mar 23, 2009 6:59 pm
by renoops67
HI
I would be intrested in one when are you thinking of geting them?
Re:
Posted: Mon Mar 23, 2009 7:13 pm
by BigBavarian
We can get them anytime with a little notice just need some names!
Re:
Posted: Wed Mar 25, 2009 9:00 am
by 89-325i
Im very interested in one but wouldent have the funds for at least a couple of months. also depends on how much to ship to New Zealand.
Re:
Posted: Wed Mar 25, 2009 6:20 pm
by BigBavarian
i'll look into shipping for you
Re:
Posted: Wed Mar 25, 2009 7:28 pm
by Dave_M3
BigBavarian wrote:We can get them anytime with a little notice just need some names!
Very good.
Reckon I'll be in touch for a few when I'm building up my track car and when I finally kill the clutch in the iS (just my luck wanting to get an iS and put a lightened flywheel into it and buying one with a new clutch just fitted

)
Does anybody have an idea if an M20 one would fit the M42?
Would just be an idea for the fact a stronger clutch could be used as well as the possibilty of easier to get the numbers together if alot of M20 flywheels were being used
Re:
Posted: Thu May 07, 2009 7:26 pm
by BigBavarian
Any body interested? Im getting one for the m52b2.8 thats going in soon
1. BBB M52 flywheel
2.
3.
4.
Re:
Posted: Fri May 08, 2009 7:23 pm
by mikekean
1. BBB M52 flywheel
2. Mikekean M20 flywheel
3.
4.
Id be interested in an m20 flywheel
Re:
Posted: Sun Jul 05, 2009 11:53 pm
by BigBavarian
If anyone is after a lightened flywheel, any application then get in touch directly with me, either pm or email thru our website. Quote e30 zone and will do the flywheels at the group buy price, max discount as have negotiated with the supplier for the M20, other applications will have to get a price on but it will be cheaper than you can get them elsewhere!
They can do any BMW in the range if they havedone one before, if they've not done one before be the first and get even more discount!
Thanks
Richard
Re:
Posted: Wed Jul 29, 2009 12:06 am
by rosscoe
This is a great performance mod,i have one fitted to the m3 touring,and wat a difference,revs like fcuk!!
Re:
Posted: Wed Jul 29, 2009 12:58 am
by Dave_M3
How much for an M42 one?
Putting in a 6 speed soon and my clutch has finally given up the ghost for an incentive to get the job done
Would one of the M20 versions fit the M42 if it's cheaper as I have a 325 starter and all that needed.
Re:
Posted: Wed Jul 29, 2009 10:38 am
by blitz877
mikekean wrote:1. BBB M52 flywheel
2. Mikekean M20 flywheel
3. Blitz877
4.
Id be interested in an m20 flywheel