Flywheel Changes

[Puntopimp]

Hey lads just seen on a Fiat forum about the potential to Lighten and Balance my Flywheel to make it Rev Quicker than it currently does.

How do I do this and how difficult is it to do??

[turbonutter69]

Just one thing to say.
You will not gain any bhp by doing this and you'll reduce the torque output of your engine.

[waynne]

It really is not worth the effort on a 1.2. It will bog down the minute you hit a hill. Plus DIY flywheel lightening is frought with problems as it is really hard to balance it properly.

[pgarner]

remove flywheel and take it to a machine shop to turn it down.
but as said it will reduce the torque when you hit a hill as there will be less weight to help keep it going

[MasterAuron]

Originally Posted by turbonutter69

Just one thing to say.
You will not gain any bhp by doing this and you'll reduce the torque output of your engine.

Ouch, huuuge myth and I must explain this to somebody once a month at least. I have just tried to get a moron on the RSOC last night to understand in fact.

Maybe someone else like OG or HDi can explain as I Cba!

[Puntopimp]

I cannot imagine it would reduce the amount of Torques just because of a slight adjustment to the vehicle piece.

MA do you wish to enlighten one?

[MasterAuron]

Later if no-one has explained I will copy and paste everything of mine from the thread on rsoc. On my phone and at work atm but ill be home in half an hour.

[Puntopimp]

ahhh fair play fella! look forward to a interesting read xD

[waynne]

A man carrying a sack of spuds up a hill will not become stronger if he puts the sack down. He will however be able to speed up and slow down more easily though and will probably go a bit quicker.

A rotating flywheel stores kinetic energy from the engine like a buffer, nothing is added or taken away from the power.

[Puntopimp]

Blimey you sound like one of those Chinese monks who always quote things starting with "In China they say"

[turbonutter69]

[waynne]

Man who use many words waste time!

[MasterAuron]

This is based upon my understanding of physics and lightweight flywheels/engine components. There may be some slight errors here and there, it was quite late and I am had been up since 5am. Here goes:

Originally Posted by MasterAuron

Huh? You must have fell asleep in school at this point, it's physically impossible for an engine with a lightened flywheel to "lose torque".

Originally Posted by MasterAuron

In which case torque still isn't "lost". A lighter flywheel will (should) have a lower moment of intertia and as a result less energy is stored within it and can transfered to the wheels. Basic physics that energy cannot be destroyed (or indeed created) just converted or transfered.







I can't explain this but I can only assume that you went to different dynos, or with severe operator error. There's not much to agree on and it's brilliant that you feel it was less torquey to drive, because it is physically impossible but common that people feel this was hence the myth. However, what you was probably feeling was the loss in the energy stored in the flywheel when pulling off and indeed perhaps when changing gear depending on your driving.



Tell me, do you know how torque is generated by an engine?



Why does everyone not fit extremely heavy flywheels and have massive torque out?

Originally Posted by MasterAuron

I meant because it's a good example of someone feeling like they had "lost torque" when actually they were feeling the loss of stored energy in the heavier flywheel.



It's a bit like saying fitting lighter wheels will decrease torque output, when in fact we all know that isn't true.

Originally Posted by MasterAuron

Most good dynos have correction built into the software for higher/lower ambient temps, but heat soak issues are certainly possible. Whatever it was it wasn't the flywheel, just coincidence!

Originally Posted by MasterAuron

Just to help you, torque in an engine is measure by the combustion load on the pistons (average) times the crank throw IE force x distance.



Moment of intertia is something very different but that's another school day all together



So by Rich's logic you are now going to put a heavier flywheel on your car and perhaps some heavier wheels and you will see a gain in torque? Bear in mind until now Rich didn't know how torque is measured and was confusing moment of inertia for something else...



I've had enough anyway, it feels like I have to explain this to someone once or twice a month when it's just very basic physics that 12 year old kids learn in school and yet still many people can't get their head around it.

Originally Posted by MasterAuron

Here you are correct, the mass of the flywheel has no effect on the turning force of the crank because torque is ANGULAR MOMENT which is calculated by RADIUS (to keep it simple) X FORCE thus on a engine torque = crank throw x combustion force on the pistons.



Now, we'll ignore the radius part for a sec and look at force. Force = Mass x Acceleration, greater mass would mean greater force IF acceleration stayed constant however a lighter flywheel will be able to acclerate faster due to its lesser MOMENT OF INERTIA (ie it has a greater ability to change direction more quickly) and as a result torque output doesn't change.



I really can't be arsed to explain any further, I'm sure all this infomation is readily avaliable from books and sh*t, alternatively ask someone who has studied physics at some point GCSE and above

Originally Posted by MasterAuron

You don't understand how it works lol. No, you haven't transferred the torque to a higher point in the rpm band at all!



Did you write that last post or get it from somewhere? Because it's a load of tripe. TORQUE is NOT VELOCITY/MOMENTUM/INERTIA! You are still saying you lose torque as wel, absolutely mental.



Engine breaking is GREATER with a lighter flywheel because it doesn't have as much inertia from the flywheel dragging on it.



Honestly I give up.

Originally Posted by MasterAuron

FML!



Hello? Heeellloooooooooooo??? Are you on this planet?



No. You need to rev it a little higher/employ greater clutch control because you have lost some of the stored kinetic energy used to launch the car, nothing to do with torque output. You CANNOT "lose" torque as I've already said, it gets converted or transferred.

No, I'm not very tolerant of ignorant or stupid people. And yes I gave up and went to bed after that.

[T9 man]

Originally Posted by Puntopimp

Blimey you sound like one of those Chinese monks who always quote things starting with "In China they say"

You are honoured sir! He is also known as Kwai Chang Waynne the TorqueCars Shoalin Priest, and Obi Waynne Kenobi our very own Jedi Knight! Much wisdom he has!

[turbonutter69]

[Puntopimp]

and what you put there MA is very ture, common sense and simple physics nice little readings there xD

[Loz]

Quite a nice little explanation here for anyone interested.

http://www.importtuner.com/tech/impp...ion/index.html

[old-git]

Quote from the above website:

Lightened flywheels reduce the amount of energy produced by an engine that's spent in moving its components (parasitic loss). Since flywheels are solid, unsprung components of a vehicle's driveline, a lightweight flywheel will decrease parasitic loss at a constant rate, improving a vehicle's horsepower and torque output (measured after the flywheel) throughout it's entire rev range.

[Prince]

Good post MA.

[Charliep]

Originally Posted by MasterAuron

This is based upon my understanding of physics and lightweight flywheels/engine components. There may be some slight errors here and there, it was quite late and I am had been up since 5am. Here goes:

I would disagree with you on this. I would have given up a lot earlier.

But you could have asked him why F1 engines have no flywheel at all, the clutch is not bigger vthan 170mm and the rims are not a humongous 20+ inches rather than 13s.

[T9 man]

I had considered a lighter flywheel some time ago now, but kept getting conflicting information on whether it was a good thing or not! I left it alone and went no further with the idea.

[MasterAuron]

Originally Posted by Charliep

I would disagree with you on this. I would have given up a lot earlier.

But you could have asked him why F1 engines have no flywheel at all, the clutch is not bigger vthan 170mm and the rims are not a humongous 20+ inches rather than 13s.

My anger keeps me going, like a Sith Lord

Originally Posted by T9 man

I had considered a lighter flywheel some time ago now, but kept getting conflicting information on whether it was a good thing or not! I left it alone and went no further with the idea.

Definately a good thing. I have just been out for a hoooon in mine after having the Sachs Peformance organic clutch and TTV Racing lightweight flywheel (3.6kgs vs 9.something). The clutch is lovely, like standard but a touch firmer and bites a little harder. Really love it, it's a perfect compromise between standard and paddle and will take more abuse than some paddles too

Have to rev the car a touch more from get go if you don't want to bog or stall but the lightened flywheel has made the car so much more rev happy. Without a doubt it accelerates faster under any condition, and the additional engine braking is nice. The tiniest tickle of the throttle and it revs up whereas with the standard flywheel the engine barely revved. Throttle needs only the tiniest blip on downshifts now it's great.

Can't get fook all heat into the tyres or grip in this weather though

[claymore]

Originally Posted by T9 man

I had considered a lighter flywheel some time ago now, but kept getting conflicting information on whether it was a good thing or not! I left it alone and went no further with the idea.

Do you have a flywheel? I thought your car was an auto.

[T9 man]

Originally Posted by claymore

Do you have a flywheel? I thought your car was an auto.

It is, that might have been the overriding factor on the decision! I did say it was a while ago now! So much for informed advice from those in the know

[MasterAuron]

Haha missed that one!