I just thought of this.. it would be cool if we could change the weight of the flywheel. heavy for drag raceing, light for circut, etc. I just put a light flywheel on my miata, and its awesome how much of an affect it made. Of course there would have to be a limit, and a really light one would require more clutch slipping to get it started, etc. So, what do you think?

I think it is a good point, but the best racing is with a completely level playing field, and as such all the cars should be, in main, exactly the same...

If you compare the rpm per second increase at maximum throttle on the XFG and the XFR you will see the difference in flywheel weights between the cars, race cars having light flywheels for maximum horsepower, as they spend a lot of time high up the rpm range...

so in some sense, it is already implemented.

but I appreciate what you are saying, I want a lighter flywheel for my Mazda 323f, know any suppliers?

Yes! But why stop there? While you are at it why not do light weight crankshafts and conrods and pistons and valves. Then make different camshafts and extra HD valve springs. Then you should be able to bore the block to oversize. Then make different exhaust headers and make the carburettor adjustable or if it has injection make that chipable. Then make it so that if you mix the wrong cam and valve spring rate or get the timing wrong you blow up your engine and need to unlock the LFS again. And if you would really like to improve the power of your engine you should be able to cut the alternator off. Like when you race side by side on a long straight.

There are just so many things you can do to your engine to make it more powerfull/responsive etc. that there is no way all of them can be added to one sim.

Oh yes this should all be in the demo.

I definitely do not want to start down the slippery slope of engine tuning. That said, I would like to see flywheel weight modeled better. I'm fairly sure that it will have to be for Scawen to add stalling and a proper clutch model anyway.

Quote from z3r0c00l :

but I appreciate what you are saying, I want a lighter flywheel for my Mazda 323f, know any suppliers?

I used Fidanza, it works great and was of good build quality. I got mine off ebay =)

And yeah, we should atleast beable to stall the car

If anyone has used LFStweak you would know that this is represented by the "time to rev" setting.

Lightening componantes in the drive system and engine do not affect the HP or Torque of the engine. What that do is allow less loss of power and torque in the the drive system to a small degree. The most noticable change is how fast the engine can rev up and down. Light=Faster rev times. Light+Stonger also means you can run up to higher reves before crap starts to break.

This kind of tuning is not needed in a pure race sim, by pure I mean one designed to present the players with a level platform from which to compete. Now there is a sim in development where this is a major part of the total package. Its basicly building to be a tool box for building, testing and racing and less a race simulator like LFS. Go look in to Drivers Republic if that is somthing you are interested in.

For pure racing I will choose LFS. For testing mods to my real car and for practicing on real world tracks I will turn to DR once it is in a more finished state.

Quote from cardriverx :

I just thought of this.. it would be cool if we could change the weight of the flywheel. heavy for drag raceing, light for circut, etc. I just put a light flywheel on my miata, and its awesome how much of an affect it made. Of course there would have to be a limit, and a really light one would require more clutch slipping to get it started, etc. So, what do you think?

You are aware that the weight (mass) of the flywheel makes absolutely no difference to the car or the engine, other than the kerbweight. It won't change how the engine revs, or how much power you get, or anything. If you think it does then you are a COMPLETE FOOL.

Quote from tristancliffe :

You are aware that the weight (mass) of the flywheel makes absolutely no difference to the car or the engine, other than the kerbweight. It won't change how the engine revs, or how much power you get, or anything. If you think it does then you are a COMPLETE FOOL.

I must admit I am a bit suprised by that statemant Tristan, care to elaborate?

The mass makes no difference - it's the inertia that counts. If you had say a 10kg flywheel with x moment of inertia, and replaced it with a 100kg flywheel with x-1 moment of inertia you'd find the engine would actually rev as quickly as a 10kg, x-1 flywheel.

Confusing weight (mass) with moment of inertia is a mistake and an inaccuracy. Just nit picking, and I'm surprised one of you didn't realise what I was getting at

Edit: I realise that reducing the mass will almost certainly reduce the moment of inertia, but it remains incorrect to say low flywheel weight is wanted.

pfffff

Come on Dan - I'd appreciate if you got a little bit more annoyed, and perhaps supplied a suitably sarcastic come-back

I know you would, which is why I am not pandering to your already inflated ego

(there, did that help? )

Hehe, tristan is right, but in a dumb way
Under the hood there is no space too use 20m long, @5mm, 30kg fly wheel, or 3cm long, @3,5m, 50kg fly wheel. There are space restrictments, and we are on the start point - we can change rev dynamics by changing a flywheels mass. Unless we are talking about fly wheels in petroleum mine

Quote from z3r0c00l :

If you compare the rpm per second increase at maximum throttle on the XFG and the XFR you will see the difference in flywheel weights between the cars, race cars having light flywheels for maximum horsepower, as they spend a lot of time high up the rpm range...

I'm sure it's because XFR has more power.

Yeah, I know space is restricted. But when we 'lighten' a flywheel, it's not the decreased mass we're after, but the decrease in inertia. It just so happens that the easiest way to decrease inertia (i.e. reduce the radius at which the mass can be considered to act) is to machine mass away or use a less dense material of the same dimensions.

I was just being picky - it's a pet hate of mine when people say one thing (lighten flywheel) but mean another (reduce inertia of flywheel), and it's not just limited to flywheel examples

Because 'lighten' implies the change of mass is the desired change, and it's not the mass (directly) that needs reducing.

It's just me being picky, and isn't worthy of this conversation really - just pretend I didn't say anything.

You just take mass aways outside edges preferably, from original flywheel to make one that has less inertia as end result of this flywheel becomes lighter.

Some n00bs take mass out from center where it mostly just makes flywheel weaker, it is not fun when your flywheel goes to pieces at 7000rpm, pieces go trough walls, not nice thing to experience.

Some rich boys just get new flywheel made according to specs, but we won't even say hello to those, damn rich spoils all sports, mumble, mumble

We need more space, Tristan's ego is too large for this room

Quote from March Hare :

...get the timing wrong you blow up your engine and need to unlock the LFS again...Oh yes this should all be in the demo.

Unlock a demo? that's a great idea...
but seriously...was that a sarcastic joke?

Quote from squidhead :

was that a sarcastic joke?

Yes. But saying it here kind of spoils it.

Yo Tristan! How else do you decrease the inertia of a flywheel in the confined space of a car? Besides I lighter car will go faster.

Quote from March Hare :

Yes. But saying it here kind of spoils it.

Yo Tristan! How else do you decrease the inertia of a flywheel in the confined space of a car? Besides I lighter car will go faster.

You could relocate weight of flywheel, remove from edges and add to center, not that it would have any point but that would do what you ask

Weight of car does not affect too much to top speed as aerodynamics come to play there more, in theory acceleration would be faster, but there is more effect if you have half tank or 3/4 (depending from tank size of course).

Quote from JTbo :

You could relocate weight of flywheel, remove from edges and add to center, not that it would have any point but that would do what you ask .

Yes but adding the weight you just removed from th outer edge to the center will increase the inertia again so that would be kind of... stoopid.

Yes yes yes. Aerodynamics. But still when battling for that 1/1000 of a second the little things do add up.

BUT! This game is a racing simulator not an educational program for engineers so all this nit picking about very small details is not what we should be doing. IMHO Is there anything humble in my opinion?

Quote from March Hare :

Yes but adding the weight you just removed from th outer edge to the center will increase the inertia again so that would be kind of... stoopid.

No, it wouldn't. Think of a figure skater doing a spin. When she pulls her arms in close to her body the spin accelerates, but her mass has not changed.

Quote :

BUT! This game is a racing simulator not an educational program for engineers so all this nit picking about very small details is not what we should be doing.

I think the point is that the closer you approximate the real thing the better result you will get and the fewer hacks will be required. If the engine actually simulated an output shaft being torqued and the clutch code actually simulated the friction of plates on a flywheel we would likely see not only very realistic clutch action, but things like stalling would be partially taken care of since flywheel mass and other such things would be taken care of already. Of course, we can't simulate ALL of these things. There's simply not enough processing power. But I think that many things can be accurately simulated while still staying very close to real life and relying on real life physics and not lookup tables or if/then statements.

[email=#*@#^@&@%]#*@#^@&@%[/email]#!!!!!


You guys got wayy too technical. Tristin, you are right, but the clutch needs to use the flywheel to connect the engine and trans, which means we cannot make the flywheel smaller. Thus, the only way to reduce inertia is to reduce the weight. This greatly effects the car, if you drove my car with the stock flywheel and the fidanza, you would see what I mean. Because there is less inertia in the drivetrain, more power makes it to the wheels, which means the car accelerates faster. The only reason you would want a heavy flywheel is in drag raceing when you have huge sticky tires that are very hard to break free off the line. Thus you need the inertia of a heavy flywheel. So, bacially, a light flywheel = a faster car. Plus, it makes shifts quicker because the revs drop faster when you depress the clutch.

Quote from cardriverx :

You guys got wayy too technical. Tristin, you are right, but the clutch needs to use the flywheel to connect the engine and trans, which means we cannot make the flywheel smaller. Thus, the only way to reduce inertia is to reduce the weight. This greatly effects the car, if you drove my car with the stock flywheel and the fidanza, you would see what I mean. Because there is less inertia in the drivetrain, more power makes it to the wheels, which means the car accelerates faster. The only reason you would want a heavy flywheel is in drag raceing when you have huge sticky tires that are very hard to break free off the line. Thus you need the inertia of a heavy flywheel. So, bacially, a light flywheel = a faster car. Plus, it makes shifts quicker because the revs drop faster when you depress the clutch.

Please, don't assume I don't know how a flywheel effects a car. And of course you could reduce the diameter of the flywheel, and use a smaller diameter clutch... And I'm not entirely sure you're right about a lightened flywheel increasing torque at the wheels - where does the extra torque come from?

Quote from tristancliffe :

Please, don't assume I don't know how a flywheel effects a car. And of course you could reduce the diameter of the flywheel, and use a smaller diameter clutch... And I'm not entirely sure you're right about a lightened flywheel increasing torque at the wheels - where does the extra torque come from?

I guess he is getting illusion from extra torque as it does rev quicker at lower gears due to reduced inertia, that way improving acceleration, but no real torque gain.

Some rolling roads are showing false torque gain as those are sensitive to how fast rpm rises and due not enough resistance lower inertia at flywheel can show up as increased torque in graph, but that is not really how things are.

Rolling road is not capable to measure power of engine anyway and depending from model there are things that you have to know to be able to get any use of them, Tristan surely knows this, not sure of others as general opinion seem to be that you can measure power of engine in such

Quote from cardriverx :

...which means we cannot make the flywheel smaller. Thus, the only way to reduce inertia is to reduce the weight...

Well, technically, no. You could remove mass from the edges of the flywheel and add it to the centre, thus mass will remain the same but moment of inertia will reduce.