Quote from Bob Smith :

OK so using these equations:

Deformation = Force / Stiffness
Frequency* = 0.5 / Deformation ^ 0.5

*which was simplified from: Frequency = 0.5 / (Force / Stiffness) ^ 0.5

Obviously increased force will increase deformation but will also reduce the frequency. How do I need to alter these equation so that downforce only affects deformation?

Hi, bob, by comparing your result and the equations, I guess that you divide the force by 2 to make the calculation(So it's the force for one wheel). Is that what you did?

Quote from colcob :

There is no such thing as equivalent mass. Force and mass are two different things so you cant just take the forces and divide by 9.8 to give you a mass. The inertia of the car (ie. its resistance to being accelerated) remains the samee regardless of downforce.

The mass remains unchanged, the suspension frequency remains unchanged. All that changes with downforce is the amplitude of the oscillation.

Could you please provide a correct formular to calculate the sprint rate? Thanks.

Hi, Bob, I'd like to present the process of my calculation:

(1) I use GRC2.2's aerodynamics and set speed at 144km/h, front wing 7 degree, rear wing 9 degrees. Then in "Force Distribution info"
the Front wheel is FF=5383N and Rear wheel is FR=8893N
(2) in Suspension Calc 0.6, I put in the result get from GRC2.2. It calculates the Equivalent Mass of
front MF=FF*0.101971621298=548.91, Rear MR=FR*0.101971621298=906.83
(3) I put in optimum frequency of front OF=2 and rear OR=2, Calc0.6 calculates that adjusted Frequency of
front AF=OF/(MF/1000)=3.6435, of rear AR=OR/(MR/1000)=2.2054
(4) Then Calc0.6 calculates the Sprint rate of
front SRF = ((AF*2*PI())^2)*MF = 287684 (N/m)
rear SRR = ((AR*2*PI())^2)*MR = 174137 (N/m)
Then the rest is depend on this calculation result

Could you please check and see what's wrong with my calculation?

I found that the less equivalent mass, the higher adjusted frequency(stiffer sprint)? Is it correct?

Last edited by khtwo, Tue 23 Aug 2005, 17:32.

Well, it seems I have worked correctly on calculation and next step is to change my drive style. Thanks!

I don't know if I'm customed to the default suspension set of LFS, the new setup calculated from the calculator feels much different to the default setup.

Quote from 5th Earth :

The force given in the GRC includes both a driver and a 50% full gas tank.

At what speed are you measuring the force, and what are your wing angles? That will make a big difference what sort of values you are getting. And what are you using as optimum frequency?

244 is within the allowed range--maximum stiffness is 260. I know that 166 and 244 is a wide difference, but bear in mind the FZ50 GTR has really unbalanced weight distribution--more than 60% of the weight is on the back, so if you use the same optimum frequency in the front and back, the front springs will be much stiffer than the rear ones. For this reason, for the FZ the "0.75 max frequecncy difference" rule doesn't apply as strictly to the FZ as to other cars.

Is this a bad thing or not? I'm not sure, really. Try it and see what the car handles like--my guess is it will handle reasonably well, since stiffer springs in the front will tend to cause it to understeer, and the FZ normally has huge oversteer.

As for 244 and 166 being high, yes those are high values, but if you are running a lot of downforce at high speed, I could see getting numbers that high. On the other hand, I would ask you if you really need that much downforce, and is your test speed really representative of your average speed in corners, which is where having the proper spring rates is most important. For example, on my oval setups, even though I can hit 283 km/hr (~79 m/s) in the straights, I test at 270 km/hr (75 m/s) because that's closer to the speed I actually carry in the corners (and incidentally, my wings are usually set around 4-7 degrees). On a tight circuit, say AS_cadet, I might set my test speed as low 25-30 m/s.

Thanks for your reply.
If I use Front wing angle of 10 and rear of 20 at speed of 144km/h
Optimum F use 2 HZ, then the Spring rate is 284356.2424(out of range) for front and 164797.7116 for rear. Does that mean we can not use Frequency higher than 1.9HZ on this car?

By the way, Bob, in your new edition of advanced setup guide, page 26, there is
"the “aero distribution” from the screenshot above should be equal to the “force distribution” when at zero speed." Should the "at zero speed" be "at all speed"?
Because at zero speed, there is no aero distribution.

Quote from Bob Smith :

GRC uses the mass of the car with the driver in and half a tank of fuel (since that's most useful). Obviously downforce is unaffected by such things.

Hi, Bob. Thanks for your advancd setup guide. Very good.
Do you think a stiffness of 244 in front and 166 in rear is normal for a FZ50 GTR?

Quote from 5th Earth :

Well, I'm biased, but I checked the math over once more to make sure I hadn't made any stupid mistakes (again), and I'm pretty confident that (f*2pi)^2*m is correct, at least judging by my source for the equation, http://hyperphysics.phy-astr.gsu.edu/hbase/shm2.html

Whether or not the fact that we're working with two tires/springs makes a difference, I don't know. I haven't thought about it before, but I don't think it makes a difference. My guess is that the slider shows the total stiffness of both springs taken together, so everything works out the same.

In that, we can't adjust the frequency higher than 2.1 because the range of stiffness in LFS is limited to 260KN/m. Could you please try to calculate the stiffness for FZ50 GTR and see the result. If I use the result, then the FZR feels like a train.

Hi, 5th World, is this calculator suitable for FZ50 GTR?

When I put in the force, the stiffness of the sprint seems huge and exceed the
range offered by LFS? (I have divided it by 1000, the result is 244 for front and 166 for rear?)

Have I did something wrong?

And in Gear Ratio Calculator, the force does not include the driver and gas, right?

Quote from Flotch :

not sure, but I have read that : spring stiffness = 2 * pi² * m * f²
where m is the mass on the front wheels in Kg (if you want to calculate springs for the front ) and f the spring frequency in Hz. And in general, lots of persons advise to begin with 2Hz, which does not really work with S2 :s

Hey, is the formular correct? In this suspension calculator(0.6), it's (2*f*pi)²*m, which is 4 * pi² * m * f². Which one is correct? I hope it's not about for one tyre or for two tyre, because in the Gear Rate Calculator it's for front and rear side (should be for two tyre).

Hey, I'm speaking from a point of view of a S2 licensed user. Considering the
group of licensed players and demo players, absolutely the demo players
group is much bigger. What now S2 licensed users can do is just show
skins in a smaller group but can not do it in a bigger group. It's the benefit
of S2 players but not the demo players. To make it clearer, try to ask yourself
if you really want to prevent demo players from downloading your own skins? I
think most S2 licensed players will answer no. That's the starting point.

Paying for something good does not necessarily mean that demo version can
not have those things. Last year, we still have to pay for the features of
current S2 demo version. And think about the success of CS, it's the pleasure
of operating on net attract so many players.

For the bandwidth cost, only devs can decide if it's worth or not to spend
higher cost to catch more registrations.

For abuse other players' skins of demo players, devs can prevent it by
disallowing demo players save the skins to disk.

The purchase value is that you can show skins to everybody without have to
ask every demo player to download it. Considering the user group, the demo
player group is absolutely bigger than licensed player group. What now S2
license can do is give you the ability to show skins in a smaller group.

To: Beandip
Sorry for misunderstanding your meaning. It's true that demo players aren't
owed anything. But why would game devs provide good demo versions to
demo players? Attract them to buy it, for sure. In other words, the devs
are responsible to the market, and demo players are the potential market.
So it's not that simple by just saying "they aren't owed anything".

To answer whether demo players own the demo version game, one can just
think if the LFS devs can force those demo players to delete the copies of
the demo game from their harddisk.

Last edited by khtwo, Sun 14 Aug 2005, 22:26.

Quote from al heeley :

Valid points, but there's also the other side of the argument, that once having paid for the game, there may be not that much extra more added that people wonder if it was worth paying for. There has to be a reasonable and significant difference between the 'free' features and the paid ones for people to have justified the purchase value.

And my suggestion will add the purchase value.

Thanks, RAYfighter! Clear and interesting expression. (Y)

Players expecting the game developers provide a better game is normal,
no matter if they are demo players or paid players. Please don't say something
like "demo players own nothing". At least, they legally own the demo version.
Please don't look down on demo players. Everybody was a demo player.
And sometimes the voice of demo players weights more than it of paid
players. The voice of "it's worth to buy it" from a demo player, or it from
a paid player, which one do you think sounds more beautiful to the game
provider?

Providing this service may increase some cost, but the cost is not that
much by applying some techniques, for example, allowing S2 licensed
players put their skins on any website and the program download skins
directly from that website. Furthermore, it acts as a free advertisement
on demo servers, and can attract more demo players to upgrade to full
licensed players. Why would a marketing expert avoid this?

Quote from Chaos :

Well for 3 years since the first demo, everybody had to put his skin somewhere for others to download and we had to live with that... I see no reason why demo racers should not...

For sure you are a LFS lover, and you have experienced the pain of "putting
skin somewhere for others to download". Why do we S2 licensed players
need to experience this pain like before when we want to show skins to demo
players? Furthermore, demo players normally are not LFS lovers, they
don't care if it needs to download others' skins.

Quote from Gunn :

The Live For Speed demo is probably the best example of a demonstration version that you will find available for any game. If any more features are included it would likely work to prevent some demo racers from buying a license. The unlicensed racer in Live For Speed is extremely well catered-for already in my opinion. I want demo racers to crave S2 features, that is a good thing for them to be missing out on things they want. They have already tried the most awesome race sim demo the next logical step involves buying a license and joining the greater community.

Some addons. Guess who is more excited, the player who is able to see other
skins, or the player who is able to show his own skins to everybody? We see a
lot of great skins and car pictures from internet every day. What everybody
want to do is showing his own style on the net in the game. Know what I mean?

Quote from al heeley :

Of course it isn't! When we only had the S1 version, we all ended up with megabytes of othe peoples skins on our hard drives; those from friends and teammates and skins we admired.
Maybe get your friends to see your full s2 then they will also want to buy their own licence!

I admit that LFS is a very good game and I love it very much. But I'm not sure
if everybody loves it just like you and me. Someone may just want to play for
several days, maybe they will love it, maybe they will not. However, I think
being able to show the skin to everybody (include S2 licensed players and
demo players) should be a great interest for every player.
As I said before, being able to show skin off and being able to see others' skin
are different things. I think limiting demo players on preventing them seeing
others' skins is not wise. This mechanism actually limits the function of S2
licensed players. Think about it from another point of view.

For sure, I will buy the license. LFS is good. For only 2 days, I begin to love it.
But I have several friends who have only demo license. It's impossible to send
all of them my skin and ask them to install it.
And considering the way it works, it's possible to download those skins from
a web server rather than LFSW servers. So it might avoid influencing the traffic
of the LFSW server.

1. No, this feature works only on S2 servers...

Hey, why not let demo licensed players download skins? Painting may spend
money because the car owner want to show it out. But watching the skin
should be free because that's what the car owner has paid.

I see. That's great. So it's a limited function only for S2 license.
I have other questions.
1. If I have a S2 license, and I upload my skin. Will those demo license players
automatically download my skin?
2. If I play LFS in a LAN, will other players be able to see my skin?
Thanks for replying so quickly.

Because the skin in LFS is rather easy to make, now there are a lot of very
beautiful skins have been developed. However, it's not easy to show those
skins unless other players download the skins first. LFS is well known for
its real. Painting our lovely cars and show them to others is also a very
interesting thing in real world. So I suggest developers add this function into
LFS and make it more enjoyable.
For technique details, maybe it can be done like this. When a player enter
into the game or change to a non-standard skin in garage, it uploads the skin
to the server. Then the server can distribute the new skin to other players.
To avoid lag, server may control the transfer rate during the competition or,
more simple, only dustribute the new skins in the seconds just before the
next restart.
Thank you all developers for taking us a so good game.