LIGHTER FLYWHEEL????

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Karan
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Post Thu May 12, 2005 11:17 am

im thinking lighter fly on my 2.7 when the box and clutch are replaced nxt week.......

where can i get one or shall i get it machined.... or shall i just leave it as it spools up very well anyway compared to most other cars ive experienced.....
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Post Thu May 12, 2005 1:21 pm

any machine shop dude, just make sure and not take too much weight off !

rule of thumb no more than a 1/3 weight can be removed, personally I'd leave it stock.
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Post Thu May 12, 2005 1:31 pm

Do we know what these flywheels are made of?

Think you can get away with shaving more off a steel flywheel than an iron one.
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Post Thu May 12, 2005 1:40 pm

they are steel

ill leaveit stock
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hoshy
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Post Thu May 12, 2005 1:58 pm

I think you should lighten it dude. with that six pot up front you wanna take as much weight of as pos :)
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Post Thu May 12, 2005 2:50 pm

lighten it!
a small (ok relatively small!) tuned up NA engine like yours should benefit more from a light flywheel, more than a bigger but lower tuned engine or a turbo'd engine....

u should have seen my 3.5 when it had the 1 or 2 kg auto ring gear flywheel on there i just stood for halof an hour blipping the throttle it was amazing!

not that ur car needs to go any faster though!
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Post Thu May 12, 2005 3:55 pm

Dont lighten it unless you gonna do the whole lot! front pulley, crank, rods,
clutch housing! and like some one else said dont take to much off!!
:?
Ive just put an 8lb ally flywheel on mine standard 18lb! im a little worried
but its a differnt style of power derlivery mines all top end screaming at
8750rpm! donthink i'll notice it to much up there!

Yours rea a lot more torquey and ya dont wanna lose that by lightening it
to much!
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Post Thu May 12, 2005 4:15 pm

M3Jimbo wrote:Ive just put an 8lb ally flywheel on mine standard 18lb! im a little worried
but its a differnt style of power derlivery mines all top end screaming at
8750rpm! donthink i'll notice it to much up there!

Yours rea a lot more torquey and ya dont wanna lose that by lightening it
to much!
:yeahthat:

(8750 rpm :eek: h*ly sh*t man :twisted: )
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Post Thu May 12, 2005 4:57 pm

M3Jimbo wrote:Dont lighten it unless you gonna do the whole lot! front pulley, crank, rods,
clutch housing! and like some one else said dont take to much off!!
:?
Ive just put an 8lb ally flywheel on mine standard 18lb! im a little worried
but its a differnt style of power derlivery mines all top end screaming at
8750rpm! donthink i'll notice it to much up there!

Yours rea a lot more torquey and ya dont wanna lose that by lightening it
to much!
lightened flywheel doesnt lose torque - a heavier flywheel only has a higher inertia, which is helpful when goin up hill when you dont have a lot of torque

I'd say do it, an engine like Karan's screamer would benefit from it
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Post Thu May 12, 2005 5:07 pm

The greater momentum of a heavy flywheel's only a help at the start of a hill.

Think of those flywheel toy cars. If you rev it up and let it loose at a slope, it'll only go a certain way up it. In a real car, the engine needs to take over at that point to keep you moving.

The flywheel only helps in transient conditions of load, not steady state.
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Post Thu May 12, 2005 5:45 pm

Turbo-Brown wrote:The greater momentum of a heavy flywheel's only a help at the start of a hill.

Think of those flywheel toy cars. If you rev it up and let it loose at a slope, it'll only go a certain way up it. In a real car, the engine needs to take over at that point to keep you moving.

The flywheel only helps in transient conditions of load, not steady state.
yep exactly - quite alot of misunderstanding about lightened flywheels
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Karan
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Post Thu May 12, 2005 5:45 pm

so where can i get it done?

is it done by drilling holes??? or shaving bits of the front in the bit nearest the block?

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Post Thu May 12, 2005 5:47 pm

any engineering place for about Ԛ£40..

They shave the back of it
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M3Compact
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Post Thu May 12, 2005 6:12 pm

Imo get it lightened. 8) (8lb is a bit eek. :eek: )

'Knifed' crank too. 8)

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Karan
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Post Thu May 12, 2005 6:16 pm

engine isnt coming apart,,,,, its not even coming out....

i may get this done then.... remember it is a everyday road car though.. dont wanna make it undriveable!

Karan
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Post Thu May 12, 2005 6:16 pm

cheers for clarifying lads!!

I now a bit more about flywheels now and im not to worried about going
up hills in mine!!!

Didnt realise karans engine was a screamer! Just thought they where
a typicaly lower reving engines!
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Post Thu May 12, 2005 6:21 pm

M3Jimbo wrote:cheers for clarifying lads!!

I now a bit more about flywheels now and im not to worried about going
up hills in mine!!!

Didnt realise karans engine was a screamer! Just thought they where
a typicaly lower reving engines!
]
its not a screamer compared to an s14..... but as far as ancient m20s go it screams like a good'un......

sings happily to 7k
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Post Thu May 12, 2005 6:49 pm

i'd say it screams pretty well :cool:

they'll skim the 'back' of the flywheel, by which i mean the forward-facing side, the other side to the clutch contact face

my m30 idled really well with the auto flywheel on, i don't think you'll make it undriveable by taking a bit off.
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Post Thu May 12, 2005 8:11 pm

That's the nice thing about having 5 or more cylinders, the flywheel doesn't need to make up for the gaps in the cycle where there's no power because the power pulses overlap.

Also, we straight 6 people get perfect balancability :)

(as do X-plane 90deg V8s and 60deg V12s)
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Post Thu May 12, 2005 10:29 pm

I had a lightened flywheel in my 4 cyl 2.0 Vaux engine. Didn't notice and difference in driveability or going up hills or whatever.

As already said, a flywheel can't alter the torque output of an engine. It's just inertia, which is the rotational equivalent of extra mass in the car. Less is better.
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Post Fri May 13, 2005 8:38 am

tomstickland wrote:I had a lightened flywheel in my 4 cyl 2.0 Vaux engine. Didn't notice and difference in driveability or going up hills or whatever.

As already said, a flywheel can't alter the torque output of an engine. It's just inertia, which is the rotational equivalent of extra mass in the car. Less is better.
Eh? you need to rememeber that once the fly wheel starts to rotate its weight doubles, dude just leave it. and toby, that M30 you were revving, i bet it was falling as fast as it was rising.

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Post Fri May 13, 2005 10:21 am

Demlotcrew wrote:
tomstickland wrote:I had a lightened flywheel in my 4 cyl 2.0 Vaux engine. Didn't notice and difference in driveability or going up hills or whatever.

As already said, a flywheel can't alter the torque output of an engine. It's just inertia, which is the rotational equivalent of extra mass in the car. Less is better.
Eh? you need to rememeber that once the fly wheel starts to rotate its weight doubles, dude just leave it. and toby, that M30 you were revving, i bet it was falling as fast as it was rising.

Andrew
only an issue with turbo'd engines where it'll drop off boost dude
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Post Fri May 13, 2005 10:58 am

Mines 25% lighter and is unnoticable on idle or cruising along.

But 1st gear and it takes off like a rocket, revs up so much faster
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Post Fri May 13, 2005 11:35 am

Matt_M44is wrote:Mines 25% lighter and is unnoticable on idle or cruising along.

But 1st gear and it takes off like a rocket, revs up so much faster
Lighter one on mines also, and i notice it on idle, the bonnet shakes!

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Post Fri May 13, 2005 12:42 pm

EEKK Shaking bonnets? wonder what mines going to be like... can't wait for super fast revving though!
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Post Fri May 13, 2005 12:47 pm

my mate has a 4kg flywheel in his corsa and it doesnt rattle or shake the bonnet
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Post Fri May 13, 2005 12:58 pm

The 'is' flywheel on the m42 is 9kg, the one on m44 is 12kg so in effect where im using the m42 one its lighter ... was thinking of having some weight shaved of then balanced when i replace the thrust bearing sooner or later, but think may be going too far ... ??

I get the very slightest vibration, don't realise it if you not been in the car before ...

does rule though ... was thinking of having the crank lightened if and when i get my cams/pullies ... hehe, going all out this time.

I want a monster that is still insurable :p
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Post Fri May 13, 2005 1:04 pm

Matt_M44is wrote:The 'is' flywheel on the m42 is 9kg, the one on m44 is 12kg so in effect where im using the m42 one its lighter ... was thinking of having some weight shaved of then balanced when i replace the thrust bearing sooner or later, but think may be going too far ... ??

I get the very slightest vibration, don't realise it if you not been in the car before ...

does rule though ... was thinking of having the crank lightened if and when i get my cams/pullies ... hehe, going all out this time.

I want a monster that is still insurable :p
crank and flywheel balanced n lightened is a very good option if your pulling it apart anyways..
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Post Fri May 13, 2005 1:10 pm

Do the whole lot! front pulley, crank, rods,
clutch housing! No vibration then!!!! :thumb:
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Post Fri May 13, 2005 1:13 pm

At the moment the E30 is my main motor for getting about everywhere so can't do much to it. e36 off the road so can have some tlc and some long deserved maintenance then im selling it ....

Options then are a cheap little fuel efficient thing that will be purely for the 250 miles a week just getting to work and back so the e30 can take a rest and have loads done to it, only driven for fun. :cool:

Cams + lite pullys, increase bore, bit of head work, light blanced crank + fly .... fancy going to town for the fun of it. It doesn't owe me anything and the shell is mint now so why not ... interesting challenge to see if i can get the little 1.9 up to 200bhp ... i know its poss as if my mate can get 178 out of his 1.8 escort Gti i think anything can be done!! :D
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Post Fri May 13, 2005 1:26 pm

if ya want 200bhp just stick a pair of weber DCOE's on it!!!

I had a set on a standard Citeron bx gti lump(1.9 16v) in my 309 gti
that put out 192bhp

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Post Fri May 13, 2005 1:43 pm

M3Jimbo wrote:Do the whole lot! front pulley, crank, rods,
clutch housing! No vibration then!!!! :thumb:
Sadly, if it's a 4cyl, there's no escaping the vibrations no matter how well it's been balanced :(
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Post Fri May 13, 2005 9:54 pm

Turbo-Brown wrote:
M3Jimbo wrote:Do the whole lot! front pulley, crank, rods,
clutch housing! No vibration then!!!! :thumb:
Sadly, if it's a 4cyl, there's no escaping the vibrations no matter how well it's been balanced :(
I know this! But the M42 has a eight way balanced crank but thats still not enough.

Andrew
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Post Fri May 13, 2005 10:05 pm

M3Jimbo wrote:if ya want 200bhp just stick a pair of weber DCOE's on it!!!

I had a set on a standard Citeron bx gti lump(1.9 16v) in my 309 gti
that put out 192bhp

Loverly carbs!!!!
Karan has a few more than 200bhp anyway dude!!
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Post Fri May 13, 2005 10:12 pm

E30Adam wrote:
M3Jimbo wrote:if ya want 200bhp just stick a pair of weber DCOE's on it!!!

I had a set on a standard Citeron bx gti lump(1.9 16v) in my 309 gti
that put out 192bhp

Loverly carbs!!!!
Karan has a few more than 200bhp anyway dude!!
he's talking about putting them on an m44 not an m20
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