Quote from Shotglass :

it was already coded into s1
but its still a bit flawed ... for one the flywheel doenst seem to influence weight at all and more improtantly if your car is too light the engine can spin the whole car high into the air in idle

The flywheel doesn't influence weight, it influences rotational inertia

And how light of a car are you talking? 5 lbs? It's not relevant how it behaves in impossible conditions.

Quote from Ball Bearing Turbo :

And how light of a car are you talking? 5 lbs? It's not relevant how it behaves in impossible conditions.

cars in the 100-200 kg range

Yep. Using the old Tweak program, you could make the engine really powerful, and put in a really heavy flywheel. The car could litterally do barrel rolls from a standing start. illepall Just floor it and the car would fly up in the air and roll over to eventually come back down on the wheels. Somebody did a video of it. You might still be able to find it on the LFS video site.

Isn't that how it should happen? I mean, 1000kg flywheel, 50000hp engine, 200kg car... barrel roll...

...If you would build such a car un real life it would probably do the same. It's the absurd specs of the car, nothing more (50khp engine weighing 100 kilograms would be nice to see )

Indeed I suspect it's the bizarre input that creates the bizarre output.

Quote from Hyperactive :

Isn't that how it should happen? I mean, 1000kg flywheel, 50000hp engine, 200kg car... barrel roll...

and how exactly would a 1 ton flywheel in a 200kg car work ?

Lol

edit: so it's impossible, but so are the specs of any car that behaves that way in LFS
edit2: what is that foreign substance you're spraying at me?

Quote from Ball Bearing Turbo :

edit: so it's impossible, but so are the specs of any car that behaves that way in LFS

might be ... but with mechanik s2 you cant change the flywheel weight so that the only thing you change is idle torque
but what happens if you start toying around with the cars weight is that there will be a threshhold where the car stands still in the setup screen and if take away only one more kg it suddenly takes off into orbit

Quote :

edit2: what is that foreign substance you're spraying at me?

you dont want to know

no seriously ... you dont

edit: you dont even have to change the engine at all ... just take the xrt and set its weight to -1,670 it will instantly take off in the setup screen even though it weights a healthy 495 kg ... as soon at you ptu the driver in itll behave normally

Quote from Shotglass :

you dont want to know
no seriously ... you dont

I kinda do, but ok, I'll be searching all over for that bottle to find out on my own. Combing the shelves at every store, I shall be. Then I'll get my OWN spray in MY avatar, MOHOOhahaha

Quote :

edit: you dont even have to change the engine at all ... just take the xrt and set its weight to -1,670 it will instantly take off in the setup screen even though it weights a healthy 495 kg ... as soon at you ptu the driver in itll behave normally

K, well you're setting the weight factor to a negative number. The problem is that our finite minds cannot grasp what number in Scawen's virtual cosmos of pseudo-physical systems we are altering in order to get our vehicle weight. We're not just entering the weight directly, and therefore you do not know what else you're screwing around with by putting in a negative number. Things are not so straight foward in "Scawenia" (that's the name of his world BTW)

Hehehe - actually I think that problem is to do with the CoG of the car minus driver moving infront of the front wheels, so the car tips over and goes weee... with the engine having positive weight just behind the wheels and the body having a large negative weight from even further behind, it's just goes spinny spinny.

hmmm interesting thought bob ... might also explain why you can go lower on a smaller displacement engine even if it has more torque ... so maybe the engines weight has nothing to do with the weight factor and is calculated from the displacement and number of cylinders

Quote from Shotglass :

so maybe the engines weight has nothing to do with the weight factor and is calculated from the displacement and number of cylinders

Indeed, this is definitely true I recall noting that back in S1, where if you modified nothing but the engine specs the car would sit different on it's suspension.

Just for the curious, here is the thread about rFactor's "gravity"

I dont think the gravity model of rFactor is wrong. I think the mass, or massdistribution of the rFactor cars is wrong. I recall reading something about massdistribution for the porsche cars in rF. They were not realistic, but did provide a realistic Porsche-handling. The discussion was wether this trick was a bad or a good thing.

But it could also be just a bug when a car is at some special spot. Maybe the gravity is correctly modelled when the car is on track.

I was reading that thread on RSC about gravity in rf and it was so funny and frustrating to read all those troll posts from rf fanboys saying that you need phd in physics to tell if there is something wrong with gravity in rf.

If the car floats it's more than just a bug - it's a feature (called rf physics). Real cars don't float...

At least people here don't blindly believe that LFS is perfect - how could it get any better then...

PS: how do the cars float in rf? any video to show, anyone? I don't have rf so I'm littlie limited with comments... Don't want to post in RSC, the behaviour of the mods seem to get worse and worse...

maybe this is why Scawen and the team chose not to go with production or known cars(Except the obvious licencing issues). This way they are not contrained to making a Ferrari handle like a Ferrari should or make a porsche handle like the arse slidy slippery engine over the rear axle bitch from hell that it is. By going in without any preconceptions of car handling they can get the physics right and in a way worry about the cars later. That thought struck me from reading the 'alertnative' thread about the ISI engine and Rfactor crazy gravity. Someone mentioned that the Porshe handled in a porshe like manner. That very statement shows what 'rival' sims are trying to do, make a ferrari handle how poeple think a ferrari should handle like, not like how it handles in real life.

I feel that LFS is giving us a 'real' physics engine, where gravity remains constant regardless whether you are on the track or 1/2 mile above it. The cars then behave appropriatly whether people regard them as handling accuratly or not. If the physics is correct then the car handling should theoretically be the most accurate it possible can be.

I'm still with LFS on this, gravity is a constant. IT should be constantly applied everywhere through out the sim. If it's not then it's not simulating anything is it.

My personal opinion is that LFS doesn't do gravity properly. It doesn't seem to use a constant downward acceleration. Take a UF1 on FE-Club and pull a jump on any of the sidehills. Once the car has reached it's max height, it seems to fall to the ground at constant velocity, rather than accelerating. The cars should hit the ground with much more force than they currently do after being airborne. (It's almost like they reach terminal velocity far too quickly, and then after than it's a constant drop to the ground)

They are not exaclty falling from a great height though are they, by the time you would have registered that there is no acceleration towards mother earth you would be eating worms. The time is too short to measure any acceleration just by a feeling . . . . Maybe if we strapped some very sensitive scientific instruments to the car and drove it off one the tower blocks in So City, then you might get a reading that corroborates your 'feelings'.

Quote from ste_ :

My personal opinion is that LFS doesn't do gravity properly. It doesn't seem to use a constant downward acceleration. Take a UF1 on FE-Club and pull a jump on any of the sidehills. Once the car has reached it's max height, it seems to fall to the ground at constant velocity, rather than accelerating. The cars should hit the ground with much more force than they currently do after being airborne. (It's almost like they reach terminal velocity far too quickly, and then after than it's a constant drop to the ground)

Is there any way to use some replay analyser to check it? Hmm, me puts white coat on and starts LFS...

You get the car, I'll get the feather. Meet you at the top . . . .

Gravity isn't a constant at all. It just so happens that the average value at sea level over the earth is 9.80665 m/s/s. A higher altitudes (out the range of a racing sim) it decreases.

Not that it matters, but I wonder if LFS's gravity is constant or if Scawen programmed it to take into acount altitide variations :

Seeing how LFS has a graphical celing (the sky box) then I would have thought not, just superfluious code that would never be needed.

I think you lose very little realism if you use constant g of 9.81 m/s2.

I can't seem to find any way to check the gravity in LFS, but for me it looks ok... did some test runs at blackwood with XRT, I had put some ramps on the main straight but there is no vertical acceleration/velocity number available...? Maybe put the ramps on the pit straight to get more air to the jumps---but that's a bit too much (or just try to get some strange collision happen where the car "jumps" very high and...)

But I'll think I do some online racing and go sleeping...

... Just downloaded your videos, I have just one comment:

What the hell kind of a "sim" is that? People compare that to LFS? I never tried rF, and after watching that it's not a likely occurance, I can tell you that... LOL

edit: and the download speed was great for me, 400kb/sec took no time

Quote from tristancliffe :

Gravity isn't a constant at all. It just so happens that the average value at sea level over the earth is 9.80665 m/s/s. A higher altitudes (out the range of a racing sim) it decreases.

Not that it matters, but I wonder if LFS's gravity is constant or if Scawen programmed it to take into acount altitide variations :

Yes, at the top of mt. Everest the gravity is 99,7% of that at the sea level. At the height of Alpha orbital station the gravity is 85-90% of normal.

It was funny to modify the constant to make gravity at the level of Mars... Everything is so slow and the jumps are can be high.