flywheel mod
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I am looking for a place to go proper lathe and balancing also. I can't find somewhere that is reliable. Sad....
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here is a very good article. there's also mention why u shouldn't lighten ur stock flywheel...
There has been a lot of talk lately regarding engine mods and bang for your buck. One of the modifications discussed was the old lightened flywheel. The mod has been used by motoring enthusiasts almost since the car was invented and even with today's modern cars, is still in use today. Now, lightening a flywheel is all well and good but, how many people really know what are the benefits, how are they produced and what must be sacrificed when bolting on a lightened flywheel.
Firstly, lightening a factory cast iron flywheel can have its dangers and is not recommended. The process of casting iron produces a metal component with a hard, fatigue resistant surface and a particularly soft core. If this hard surface is removed during the lightening process ( which it often is ) then this will seriously weaken the flywheel and could result in the wheel coming apart at high rpms, possibly taking the gearbox and your legs with it.
So how does a lighten flywheel work? Amongst the majority, there are two schools of thought concerning light flywheels. The first is that they do not contribute to power output. The second is that they do. Which thought is correct? In fact both, in a way, are correct.
If we measured the power output of an engine first with light flywheel and then again with the standard part on an engine dyno, no change in power will be seen to occure. At first it appears that the light flywheel has done nothing and was a total waste of cash. This is not the case. A dyno that shows max power at constant revs does not demonstrate what occurs to an engine's power output in real life situations - like acceleration. If an engine is accelerated on a dyno ( we are talking about a rate of around 2000rpm a second ) it would show a power output of around 20%-25% less than at the constant rev state.
The reason for this is that when accelerating a vehicle the engine not only has to push the total mass of the car but the internal components of the engine need to be accelerated also. This tends to absorb more power as the extra power is used accelerating the internal mass of the engine components and is why a motor accelerating on a dyno will produce less power than at constant revs. Also it must be remembered that the rate of acceleration on the engine internals is much greater that the rest of the car. This would then suggest that by lightening the flywheel, less power would be required to accelerate it and therefore more power would be available to push the car along.
Now, it may seen unbelievable that by removing a few kilos from the flywheel a noticeable difference to a 1000+ kg cars acceleration will be made. In fact the difference is quite noticeable and the secrete behind this is hidden within the gearbox. Everyone knows that cars accelerate at a greater rate in low gears, this is because a cars gear box basically a mechanical leaver and just like when using a leaver to lift a heavy object, the gearbox reduces the mass of the car that the engine sees. For example, in first gear an engine will see the cars mass as only around say 100kg but the engine internal mass would still remain around 20+kg .
It is now easier to see were the extra performance comes from when you lighten a flywheel. In some cases, and not necessarily extreme ones, you could effectively " lighten " a car by 20% in first gear just by removing mass from the flywheel. As the gear used increases this "lightening" effect is reduced. This is why car蓅 acceleration reduces in higher gears, to almost no effect in top gear. Great for drags and tight race tracks but will not increase a cars top speed one bit.
Now if having Lightweight flywheels work so well, why are they so heavy from the factory? The answer to this is quite simple. When a lightweight flywheel is installed, smooth idling almost always suffers - more so if standard cam timing is used. If a longer period cam is used, the situation is not quite as bad. With such a cam the valves close much later in the cycle so it doesn蓆 take as much flywheel energy to run the piston up on the compression stroke and the idle is by nature smoother.
There has been a lot of talk lately regarding engine mods and bang for your buck. One of the modifications discussed was the old lightened flywheel. The mod has been used by motoring enthusiasts almost since the car was invented and even with today's modern cars, is still in use today. Now, lightening a flywheel is all well and good but, how many people really know what are the benefits, how are they produced and what must be sacrificed when bolting on a lightened flywheel.
Firstly, lightening a factory cast iron flywheel can have its dangers and is not recommended. The process of casting iron produces a metal component with a hard, fatigue resistant surface and a particularly soft core. If this hard surface is removed during the lightening process ( which it often is ) then this will seriously weaken the flywheel and could result in the wheel coming apart at high rpms, possibly taking the gearbox and your legs with it.
So how does a lighten flywheel work? Amongst the majority, there are two schools of thought concerning light flywheels. The first is that they do not contribute to power output. The second is that they do. Which thought is correct? In fact both, in a way, are correct.
If we measured the power output of an engine first with light flywheel and then again with the standard part on an engine dyno, no change in power will be seen to occure. At first it appears that the light flywheel has done nothing and was a total waste of cash. This is not the case. A dyno that shows max power at constant revs does not demonstrate what occurs to an engine's power output in real life situations - like acceleration. If an engine is accelerated on a dyno ( we are talking about a rate of around 2000rpm a second ) it would show a power output of around 20%-25% less than at the constant rev state.
The reason for this is that when accelerating a vehicle the engine not only has to push the total mass of the car but the internal components of the engine need to be accelerated also. This tends to absorb more power as the extra power is used accelerating the internal mass of the engine components and is why a motor accelerating on a dyno will produce less power than at constant revs. Also it must be remembered that the rate of acceleration on the engine internals is much greater that the rest of the car. This would then suggest that by lightening the flywheel, less power would be required to accelerate it and therefore more power would be available to push the car along.
Now, it may seen unbelievable that by removing a few kilos from the flywheel a noticeable difference to a 1000+ kg cars acceleration will be made. In fact the difference is quite noticeable and the secrete behind this is hidden within the gearbox. Everyone knows that cars accelerate at a greater rate in low gears, this is because a cars gear box basically a mechanical leaver and just like when using a leaver to lift a heavy object, the gearbox reduces the mass of the car that the engine sees. For example, in first gear an engine will see the cars mass as only around say 100kg but the engine internal mass would still remain around 20+kg .
It is now easier to see were the extra performance comes from when you lighten a flywheel. In some cases, and not necessarily extreme ones, you could effectively " lighten " a car by 20% in first gear just by removing mass from the flywheel. As the gear used increases this "lightening" effect is reduced. This is why car蓅 acceleration reduces in higher gears, to almost no effect in top gear. Great for drags and tight race tracks but will not increase a cars top speed one bit.
Now if having Lightweight flywheels work so well, why are they so heavy from the factory? The answer to this is quite simple. When a lightweight flywheel is installed, smooth idling almost always suffers - more so if standard cam timing is used. If a longer period cam is used, the situation is not quite as bad. With such a cam the valves close much later in the cycle so it doesn蓆 take as much flywheel energy to run the piston up on the compression stroke and the idle is by nature smoother.
But sometimes it's hard to get an aftermarket for such a weak engine like mine. No companies will make it. sure loss like hell.
Yeah, you are right bro. But the problem is, where can i do a proper balancing? I asked a few mechanics here. They just measure the surface so that it's even. WTF? Is that the right procedure?
Please help.
Please help.
hmmm..we hv to measure the weight....let say stock is 8kgs n we want to remove 2 kgs out of it....just make sure the final weight after skimming jon is 6kgs... n yes measuring the flatness of its surface is one way to know wether its balance or not i think..but its an odd method....my mechanis send to one machine shop in senawang......a friend of mine reduce 2kgs from stock b16a flyweel and so far he never complain...i assume it works well...
Thank you so much bro. I have to trust them then. i am scared that they will screw up the flywheel.
bro,
make it easier.. buy an aftermarket flywheel.. spoon ka, j's racing ka, toda ka.. no need to worry.. plus the article does say lightening stock flywheel is not safe.. just my 2 cents
make it easier.. buy an aftermarket flywheel.. spoon ka, j's racing ka, toda ka.. no need to worry.. plus the article does say lightening stock flywheel is not safe.. just my 2 cents
Hello bro, thanks for the advice. The problem is i cannot get an aftermarket flywheel for my weird and weak engine. HAahah! Sad.....
if u're planning on changing ur engine, dun waste ur money modding the engine u have now.. if not will waste a lot of money... but if you aren't planning of changing it, i guess u'll just have to invest more time and effort into searching for one.. all the best dude
hmmm.... to me, aftermarket flywheel is usually too light (up to 3.9kgs) to be used for street driving..even it's good for track, drag n whatsoever race, it's not that favourable when it comes to normal town driving...but when u just remove 1-2kg out of ur stock...u can always maintain the std feeling driving pleasure with a bit of improvement in acceleration......this is just my opinion...never tried any spoon/toda/etc flywheel myself tho....
WhiteSpoonCivic said:
I am not planning for an engine change anyway. You are right bro, have to spend a lot of time and effort. Have to keep trying before going for the last resort. SKIMMING!!! hahahah!
i'm currently using a toda flywheel (bout 3.9kg).. i find it easier to drive as in it won't jerk like when i was using normal flywheel at rpms as low as 1.5k so i can not pump on my racing clutch too much :p
i also find that the car dun feel like it needs a lot of power to accelerate at low to mid rpms
i also find that the car dun feel like it needs a lot of power to accelerate at low to mid rpms
Oderf said:
You are right bro, it's not very comfortable to have a flywheel too light. But, there are risk of skimming also. Both have pros and cons.:confused_smile:
xxxx said:
hello brother sifuu, please help.
My engine is ME515 carbie with gearbox M154 in SR4 chasis code EG5
ME515 is SH4's engine if not mistaken.:confused_smile:
one of the member here is selling his ME516 flywheel and clutch. Can i use it? I am planning to lighten it and use it.
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