Worth skimming flywheel
Moderator: martauto
Yes!!
Makes a big big difference. Dont skim it too much though.
Makes a big big difference. Dont skim it too much though.
I will find out how much it costs.
And yes Im following you!
Are you fitting a Schrick cam? If not why not?
And yes Im following you!
Are you fitting a Schrick cam? If not why not?
I think around 60-70 Pounds would do the machining work.
The difference is vastly improved throttle response and the engine revs alot better. There is hardly any extra vibration.
One of the best mods you can do to be honest.
The difference is vastly improved throttle response and the engine revs alot better. There is hardly any extra vibration.
One of the best mods you can do to be honest.
i just changed my flywheel this weekend....it was flywheel from a 2.0 and its lightened to 6.1kg.just paid 33pounds for it...(converted from norwegian money).
its a big difference,so much cooler when the kick comes at 4000rpm ;) oooh!
so with a chip,sebring exhaust,bbtb,lightened flywheel and nos the 325 is a very funny car!!mmm!!
just need a head to port and polish and shit....hopefully before summer is here
lighten your flywheel....NOW!
its a big difference,so much cooler when the kick comes at 4000rpm ;) oooh!
so with a chip,sebring exhaust,bbtb,lightened flywheel and nos the 325 is a very funny car!!mmm!!
just need a head to port and polish and shit....hopefully before summer is here
lighten your flywheel....NOW!
Kenny
i just changed my flywheel this weekend....it was flywheel from a 2.0 and its lightened to 6.1kg.just paid 33pounds for it...(converted from norwegian money).
its a big difference,so much cooler when the kick comes at 4000rpm ;) oooh!
so with a chip,sebring exhaust,bbtb,lightened flywheel and nos the 325 is a very funny car!!mmm!!
just need a head to port and polish and shit....hopefully before summer is here
lighten your flywheel....NOW!
its a big difference,so much cooler when the kick comes at 4000rpm ;) oooh!
so with a chip,sebring exhaust,bbtb,lightened flywheel and nos the 325 is a very funny car!!mmm!!
just need a head to port and polish and shit....hopefully before summer is here
lighten your flywheel....NOW!
Kenny
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Jhonno
- Homo Hair
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you dont lose torque with a lightened flywheel but less energy is stored in it, so if you have a smaller engine then you might have to use a bit more gas uphillE30Adam wrote:The revs also drop quicker and you lose torque and momentup when going up hills if you skim the flywheel.
lightened flywheel is the way forward imo
I read a thread somewhere (maybe even here?) where someone was saying that a flywheel that isn't lightened correctly could be weaker and shatter or something. Is this correct? How hard is it to lighten a flywheel, should I be able to trust the people I get to do it or would it be better to just to buy a new flywheel that has been constructed lighter (not lightened after it was made)? If it isn't too difficult to do it properly than I guess a good machine shop should be able to do it and I shouldn't have to worry about a piece of flywheel in my leg?
Aston
Aston
BMW E30 323i with some stuff
1:05.17 @ Queensland Raceway Sprint track
1:10.09 @ Queensland Raceway Clubman track
1:21.67 @ Morgan Park Raceway
1:05.17 @ Queensland Raceway Sprint track
1:10.09 @ Queensland Raceway Clubman track
1:21.67 @ Morgan Park Raceway
had mine done last month - cost Ԛ£45 from an engineering shop in surrey/sth london - guy does a lot of machining etc on modified bmws - had it as light as the guy would take it - i'd only use guy who has done it before and preferably with a 45 degree section from outside of flywheel to recess which is cut out for strength.
if you are going to lighten the flywheel make sure you get all bottom end balanced - with clutch etc. i have spent a lot of time prepping the bottom end on my 2.7 - which means i have got a strong platform for any future planned mods
light flywheel = much better engine response - v noticeable when double de-clutching down through the box BUT although car does not have correct chip yet and now cam is 284 - idle quality is poor - but that is probably as much to do with cam/chip/not bothering to adjust idle speed.
worthhile mod - but balance bottom end as well to really make it worthwhile
if you are going to lighten the flywheel make sure you get all bottom end balanced - with clutch etc. i have spent a lot of time prepping the bottom end on my 2.7 - which means i have got a strong platform for any future planned mods
light flywheel = much better engine response - v noticeable when double de-clutching down through the box BUT although car does not have correct chip yet and now cam is 284 - idle quality is poor - but that is probably as much to do with cam/chip/not bothering to adjust idle speed.
worthhile mod - but balance bottom end as well to really make it worthwhile
318is - my mate david cottrell sorted this side of things:
Balancing was done by Dermot in Walton, 01932 245 413, don't remember the price but I think it was less than Ԛ£100 for crank, rods, pistons, flywheel, clutch - might be an idea to mention referral from david cottrell if you call
i note you are in woking - david is based in walton down the road and is going to start work on another 2.7 for me using all the spare bits i accumulated from last build - he's an ex toolmaker and v.thorough - if you need any help on builds i'd highly recommend him - pm if you want his details
Balancing was done by Dermot in Walton, 01932 245 413, don't remember the price but I think it was less than Ԛ£100 for crank, rods, pistons, flywheel, clutch - might be an idea to mention referral from david cottrell if you call
i note you are in woking - david is based in walton down the road and is going to start work on another 2.7 for me using all the spare bits i accumulated from last build - he's an ex toolmaker and v.thorough - if you need any help on builds i'd highly recommend him - pm if you want his details
- tomstickland
- E30 Zone Regular

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I ran a lightened flywheel in my Astra GTE. Well worth doing.
[quote]The revs also drop quicker and you lose torque and momentup when going up hills if you skim the flywheel.[/quote[
You don't lose torque; the engine doesn't know what intertia flywheel is fitted.
You do have less angular momentum stored up in the crank/flywheel.
Saying that this makes hill climbing worse also means that it makes acceleration from standstill better.
In any gear, the extra flywheel inertia could be replaced by extra mass sat in the car.
When you put a sack of potatoes in the back of the car you don't really notice the extra momentum helping you up a hill, but you quickly notice the extra mass slowing acceleration from standstill.
The main advantages are:
-revs rise quicker when doing gear changes
-improved acceleration in 1st gear (effect tapers off very quickly up the gears)
[quote]The revs also drop quicker and you lose torque and momentup when going up hills if you skim the flywheel.[/quote[
You don't lose torque; the engine doesn't know what intertia flywheel is fitted.
You do have less angular momentum stored up in the crank/flywheel.
Saying that this makes hill climbing worse also means that it makes acceleration from standstill better.
In any gear, the extra flywheel inertia could be replaced by extra mass sat in the car.
When you put a sack of potatoes in the back of the car you don't really notice the extra momentum helping you up a hill, but you quickly notice the extra mass slowing acceleration from standstill.
The main advantages are:
-revs rise quicker when doing gear changes
-improved acceleration in 1st gear (effect tapers off very quickly up the gears)
i would always go to someone who has some experience with the same type of engine. as was said earlier if you take too much metal off it, it can severely weaken it ...if it cracks it will come flying out of the bellhousing smashing anything in its way and trashing the gearbox and crankshaft there is some confusion with what was said earlier in the thread where it was referred to as skimming this is where the clutch plate has worn and scored the surface ,this can be skimmed to restore a good surface as for the other type lightening and balancing is normally best done when building a complete engine where the whole lot is asembled flywheel/crankshaft/rods and even the pistons are weighed and balanced on get much of a benifit. a lightened flywheel on its own wont make much difference and can also affect the idle of the engine
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jamie325isport
- E30 Zone Regular

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crazynor wrote:i just changed my flywheel this weekend....it was flywheel from a 2.0 and its lightened to 6.1kg
does anyone know the weight of a standard fly wheel (91 325)?
Has anyone who had there flywheel lightened proffessionally weighed it when they got it back? Or if they know the before and after width?
Anyone had one shatter on them? If so do you know how much weight was taken off?
Any idea what its made of?
This sounds like a good mod, i can get the use of a grinder (surface or ring) can someone post up a photo of a fly wheel? both sides of it would be good.
I know its a fairly demandig list but all input welcome.
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TouringMatt
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Had an ultralight flywheel on my Mini, looked like this...

Really had to make sure it was all done and set up well - think where you sit in a Mini in relation to the flywheel.... if it shattered at best you'd sing soprano for the rest of your days!
Matt

Really had to make sure it was all done and set up well - think where you sit in a Mini in relation to the flywheel.... if it shattered at best you'd sing soprano for the rest of your days!
Matt







