Lightened Flywheels

[BigBavarian]

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 4.5kgs 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.

[march109]

How does it release power from the engine? a flywheel isn't even part of the engine, although it is connected. It simply reduces losses.

My maths show it would be equivelent to approx 20kg of mass on the main vehicle per 1kg of mass removed from the flywheel in first gear on a sport gearbox.

Assuming for a minute I fitted a fly 3kg lighter to my 225bhp 1400kg Sport it would only be worth 7bhp on my bhp per tonne figure.

I'd still buy one though. Find me another 7bhp gain for £230 for an M20.

Got a dyno run to prove 60bhp more? and I'll eat my words.

[march109]

1. March109 (and I'll be the first to dyno it too!)
2.
3.
4.

[BigBavarian]

The 60hp was from a piece of calculation from an american engine tuner - will dig it out and reproduce it on here. Would be nice to get an extra 60hp to the wheels from simply a flywheel but i don't think it will be on these engines!
Having looked back over my claims above, i will reproduce the article as thinking about it 60hp is rather a lot on a 190 bhp engine but nt a lot on a large litred american gas guzzler, whic is probably what he was studying.

I can say that on a vauxhall corsa running a 2 litre 16 valve engine, 15bhp was the gain at the wheels in first gear with a decreasing gain through the gears thereafter.

As far as releasing power is concerned, you get figures at the flywheel and at the wheels, the lighter flywheel will allow more gain at the wheels as it is not tying the power up in mass at the flywheel.

They supply flywheels for the BTCC touring car of Rick Kerry and the Top gear 330 diesel Britcar as well as mostt he cars on the grid of several tin top series racers - Kumho,TTRS.

It is easy bolt on power release and will transform your cars performance making it an easier revving car.

Have one on my Mk 1 escort and it made it a completly different car to drive, much more throttle responsive throughout the rev range.

Thanks March, needed to explain myself better!
Any questions then please ask and will go and ask them to answer for me!

[march109]

I've allready done the math for M20's :

To save doing calculations of moments of inertia which I honestly don't ever want to think about again I shall try demonstrate the benefit of mass reduction by assuming it was infact all taken from the same distance from the centre of the flywheel on a BMW 325i sport, I will also show the equations, assumptions and fact used to calculate so that you can replicate the maths for any given vehicle you wish.

Gear Std Ratio Sport Ratio
1st 3.83 3.35
2nd 2.20 2.03
3rd 1.40 1.36
4th 1.00 1.00
5th 1.81 0.81


15 inch BBS Wheels and 55 profile tyres (205/55/15) or 17.2inch Diameter.
Mass removed from flywheel between 6 and 5 inches (average 5.5 for figures)
Because I'm not using the correct moment of inertia figures are proof of concept only and not fact, they do profide a good guide though since all other information and data is based upon fact.

[march109]

Ratio of 1lbs of flywheel mass to Xlbs's of sprung mass =
0.5 * (r * 2) * (g * 2) + R2 / R2
distances qouted in inches (American source).
as its a ratio its directly comparable to 1kg : Xkg


Examples for 1st gear sport and non-sport ratios
(0.5 * (6 * 2) * ((3.83*3.91) * 2) + (17.2 / 2)) / (17.2 / 2) = 21.9
(0.5 * (6 * 2) * ((3.35*3.91) * 2) + (17.2 / 2)) / (17.2 / 2) = 19.3

Gear Sport Ratio 1kg Equivelent 2kg Equivelent
1st 3.35 19.3kg 38.6kg
2nd 2.03 12.0kg 24.0kg
3rd 1.36 8.4kg 16.8kg
4th 1.00 6.5kg 13.0kg
5th 0.81 5.4kg 10.8kg


Thanks to E30Zone, E30Tech, RetroBMW, Wikipedia.org, How to plan and build a Fast Road Car by Daniel Stapleton and Finally Four Stroke Performance Tuning by A. Graham Bell, for reference.

[march109]

Therefore at 3kg lighter on my 1400kg sport with 220bhp

Power per tonne
= (power/mass) * 1000
= (220/1400)* 1000
= 157.15 bhp

Power per tonne with 3kg saving on the fly = 57.9kg (in first gear) equivelent.
= (power/mass) * 1000
= (220/1342.1)* 1000
= 163.9 bhp

or 6.77 bhp per tonne.

My E30 is however more powerfull butslightly heavier than the majority, as I've shown my working though the math can be replicated for any vehicle.

[march109]

1. March109 (and I'll be the first to dyno it too!)
2.
3.
4.

[Jon_Bmw]

March, 225bhp on your sport?

[march109]

March, 225bhp on your sport?

Sorry 220, typing error. My figures in the bhp/tonne figure reflect the true figure.

Were you not there when it was tested at Fritz'?? thought you may have been on the zone RR day but my mind isn't as clear as it was 5 hours ago.

I'm 99% sure you were though. You'll see I never claimed to have more than 220 other than here and one other post, but my signature should show me up on that score.

I don't have the typical sport, you know that.

[Jon_Bmw]

I was there sir. That car never made a smidge over 200 brake with a 6 branch back in its hay day...

And my iS made 10% over a standard iS and its...standard... See what I am getting at. 220 * 0.9 = 198.


Edit: I wasn't worried about the 5 brake!

[march109]

I'm working with what I've got. A piece of paper with a number on. The M50s made nearly stock power that day did they not? in fact didn't we have a thread with the numbers on?

Anyway regardless, RD 6 branch, New standalone, Alpina head and lightened flywheel all being fitted this winter.

[march109]

Odd from the thread on theday an M40 made 112.9, so 2.1bhp down on new. the M50's were near enough making stock power, but all the is' made over the stock figures. Yours even made 455.5 according to the thread too.

I will be getting mine tested again soon though we shall see. It has had a new cam since the days of the 6 branch though.

[Jon_Bmw]

Indeed. Dynos are good for comparisons, so it will be good to take it back and see what your work has unleashed. Sounds like quite a chariot in the making.

alex's m20 325 standard made 189, 10% over.
auto 325 made 188, meaningless as its auto really.
m50b28 made 218bhp, 10% off would be 196, which is a bit more than factory(better inlet manifold mind)
two iS's made nigh on 150bhp.

[march109]

I'm running it on another dyno for a comparison before any work, but then back to Fritz hopefully for the work and a new power run to see what I have got.

If you want to pilot a proper car pop down to Bournemouth.

And its already is a bloody chariot and stop ruining this group buy. I want a lightened flywheel.

[Jon_Bmw]

Sorry folks. Have a look here Gareth:

http://www.e30zone.net/modules.php?name ... &start=100

Its certainly a chariot, looks great with the wheels.

I'm a 4v per cylinder man, well for performance anyhow...

[tomson]

I'm a 4v per cylinder man, well for performance anyhow...

You must be talking about the Pug then Jon!!

[Jon_Bmw]

I'm a 4v per cylinder man, well for performance anyhow...

You must be talking about the Pug then Jon!!

For shizzle, not that wheezy underpowered m42 lump!

[shorty73]

1. March109 (and I'll be the first to dyno it too!)
2. shorty73 4kg preferably but 4.5 if it suits everyone else.
3.
4.

[e21Jason]

1. March109 (and I'll be the first to dyno it too!)
2. shorty73 4kg preferably but 4.5 if it suits everyone else.
3. e21Jason
4.

[bss325i]

Therefore at 3kg lighter on my 1400kg sport with 220bhp

My E30 is however more powerfull butslightly heavier than the majority, as I've shown my working though the math can be replicated for any vehicle.

Gareth, how is your sport 200kg heavier than others?

A standard 325i 2dr saloon's unladen weight with a full tank is 1200kg.

A sport cant weigh much more, say 50kg dependant on equipment?

[march109]

I guestimated it with full tank and my fat arse sat in it (I have a fat arse!). Remember equipment wise I also have a few toys and aftermarket sterio equipment including subs.

In fact I reckon my biggest performance gain would come from not eating so many pies, I could easily afford to loose 25kg.

[shorty73]

I guestimated it with full tank and my fat arse sat in it (I have a fat arse!). Remember equipment wise I also have a few toys and aftermarket sterio equipment including subs.

In fact I reckon my biggest performance gain would come from not eating so many pies, I could easily afford to loose 25kg.

Could you work out how much of a gain I'd get? My car weighs in at 1060 with me in it and a sport box.

My heads frazzled with maths from a days electrical engineering!


What clutches are recommended for the race and road versions?

[BigBavarian]

Road versions are raod clutches, race versions are paddle clutch fitment, they can suply paddle cltch aswell if required. If anyone has any questions then please feel free to call me 07858 151 197, will do t best o answer and if i can't i can go and get them!

[Simon13]

fotget all that maths bullshit, just fit one. They work end of.

Less weight on the moving parts of the engine. Less work for it. The lighter they all are the better they rev and get the power down.

These transform a 325i.

4.5 kgs if fookin light. I have a 5.5 one and that rules

You'll still notice the extra urge in 4th and 5th gears. 3rd is like 2nd etc

Economy will imporve a touch too!

[Jhonno]

Guys if I wanted an S50 one, would it be best if I brought an S50 flywheel up for them to get dims etc off?

[BigBavarian]

I believe they have all the stuff for the s50 too as they do a couple of kumho cars, will check with them next week and let you know beforethe bbq, our man will be there then, never one to refuse free food!!!

[Jhonno]

never one to refuse free food!!!

A man after my own heart!

[BigBavarian]

1. March109 (and I'll be the first to dyno it too!)
2. shorty73 4kg preferably but 4.5 if it suits everyone else.
3. e21Jason
4.

Anyone else? we are going to find out a cost for these 3 if we can get 1 more person we maybe able to do them for the 5 people price and jhonno we will see if we can get your s50 in that price too..

Andrew

[Jhonno]

[BigBavarian]

if you're really lucky jhonno we may have it for the bbq on friday, give you a little incentive to get it done quicker!!
Andrew

[Jhonno]

if you're really lucky jhonno we may have it for the bbq on friday, give you a little incentive to get it done quicker!!
Andrew

Like I need any incentive!!

I just need time.. Atm it would have to be a start Fri eve finish by Sun eve job

[oze30]

Any news on the S5x flywheel?

[BigBavarian]

We have got to go and speak to them today about the m20 flywheels so i will find out then.

[bigdoe]

very interested in one of the m20 flywheels,if i put my name on the list what is the approximate delivery time?.