I've built up a suspension frequency calculator in the last couple of days since the old S1 version didn't work very well on my computer (I don't have Excel).
It seems to give pretty much the same values as the previous one, though I have calculated the damping slightly differently.
Anyway, in an attempt to recover my previous speed at BWGP in the XF GTi I downloaded some WR setups and looked at them in my spreadsheet.
The suspension frequencies were around 3.2Hz and both axles were near critical damping. The setup, however, worked much better than the one I was using which had frequencies of about 2Hz and damping 80% of critical as suggested in the advanced setup guide.

So, what's wrong? All the rules of thumb I've seen for suspension setup seem to be wrong.

To cut all the point from the other thread, 2Hz and 80% damped are real life figures know to work well. But even in real life these vary alot depending on the tyres and the track. In LFS, with our rather "unique" tyres, and obviously physics that are a lot simpler than the real world (but damn good all the same), optimum values are obviously going to be different. I kind of mention this in the guide too.

I'm not much of a FWD racer but I'm aware they can cope with very high spring frequencies, unlike the RWDs where anything over 3Hz starts to make them difficult to control.

Basicly, with any guide, it would make sense to use the suggested values as a starting point, but don't be afraid to experiment. If you find something is faster or works well for you, use it. And if you want to share your knowledge with others, that's great as well.

I've found that with the RWD cars the only way I can have any confidence and go mainly forwards instead of spinning on power, is to have spring frequencies nearer 4Khz. Is this just me? With the higher frequency I seem to be able to lean on the car a lot more.

4Hz, no?

4Hz? Which RWDs are you talking about, the road going ones, the GTRs or the Formulas?

I was talking about the road cars in my previous post. The GTRs seem to work wellaround 3Hz and the Formulas nearer 4Hz. So until you specify I can't really answer your question.

3-4Hz is quite good, on each car. I have the feeling that the tires work better when there is only very very few body roll. I did some test in rallycross, and it is true that being very stiff is not a problem, and being soft is one : the few time you could gain by having a better traction is lost because you cannot take the corner as fast as the tires can go.

Doh, yes I meant 4 Hz, not KHz!

The car I've been using is the XR-GTR, and I think my springs are definitely at the higher end of the frequency range. Here's the set attached.

Hello bobsmith and colcobb. I’m not as good in English, as MS Word 2002 do, but if he doesn’t fix wrong spelling somewhere, feel free to ask me that exactly I was meaning there )

From Advanced setup guide:

Quote :

So obviously there is an optimum point in spring frequency – in real life this is known to be around 1.9-2.2Hz for cars around 1 tonne in mass (typical for GT racing cars). That doesn’t automatically mean these frequencies are best for LFS, however. As the weight increases this optimum frequency decreases and vice versa. Since the heaviest car in the game clocks the scales at just over 1.2 tonnes, 2Hz should still be a good point to start from and I wouldn’t recommend dipping much lower. For lighter cars, this optimum point may reach as high as 3Hz, although I wouldn’t recommend going quite that high for any road car in LFS.

The heaviest car in game is FZ50, it has 1379 kg clean, and about 1.5 tonnes with driver and some fuel onboard. However, it has 2,8Hz R/2,9Hz F in today's WR setup. I've analyzed all BL1 WR’s setups. Minimum frequency was 2,47 (Lx4 Rear) and maximum was 3.95 (FV8 Rear). I'm not taking into account extreme 4.42 Hz on UF 1000 Rear.
Overage value is 3.05 Hz while average weight is 941 kg. Seems that in LFS the rule of more weight needs less freqs isn't work at all? Light MRT has a very low freqs, heavy rb4 opposite. Is it just car-specific thing in LFS and has nothing similar to RL GT racing setups?

Probably not. Firstly I thought that this frequency is an absolute value. I multiply that on 1000 and divided on the mass of a car to get a relative value to 1 tonne. The result was perfectly suited frequencies! Heavy cars shows low 1,9Hz/tonne, midweight about 3-5Hz/tonne and MRT shows about 8-10Hz/tonne.
But when I looked how that frequency calculates in Setup Analyzer, it seems like it already care ‘bout this, ‘cause it involves the mass of the car and value 1000. What I see is must be a relative to 1 tonne result. I just can’t understand this twist so maybe you can help me. Here is my Excel calculations attached.
If they are wrong, why the heck are they so perfectly match the RL?


WBR,
Belozersky Eugene, aka jenek

I'm not sure I fully follow your analysis, but I can say that the frequency values in the spreadsheet are absolute, not per tonne. And the *1000 you see is simply to convert the spring rate from kN/m to N/m.

Personally I dont particularly hold the opinion that lighter cars need higher spring frequencies and heavier ones need lower spring frequencies, so I wouldnt worry about it too much.

Quote from jenek :

The heaviest car in game is FZ50, it has 1379 kg clean, and about 1.5 tonnes with driver and some fuel onboard. However, it has 2,8Hz R/2,9Hz F in today's WR setup. I've analyzed all BL1 WR’s setups. Minimum frequency was 2,47 (Lx4 Rear) and maximum was 3.95 (FV8 Rear). I'm not taking into account extreme 4.42 Hz on UF 1000 Rear.
Average value is 3.05 Hz while average weight is 941 kg. Seems that in LFS the rule of more weight needs less freqs isn't work at all? Light MRT has a very low freqs, heavy rb4 opposite. Is it just car-specific thing in LFS and has nothing similar to RL GT racing setups?

Well, there are lots of things to consider. For starters softer springs give more grip, but more body roll (CoG movement), which reduces grip. At some point there will obviously be an optimum frequency for grip. This also depends on how bumpy a circuit is. It also doesn't mean that you will be fastest with this frequency, just that in theory that's when most grip is available, so you probably don't wont to stray too far from it.

On the MRT5 for example, I suspect the CoG is very low, so softer springs work well since you gain grip without too much extra body roll. You still get a lot of weight transfer without CoG movement anyway, so you're unlikely to make a dramatic difference to tyre loads with just the springs.

The UF1000 is a special case, the lack of anti-roll bars mean that a) stiffer springs in general are needed to reduce body roll and b) the basic car balance has to be done entirely with the springs, so the rear will be a lot higher than the front on that car.

Also driving style is important, myself I don't like stiff setups too much, I prefer a more playful car for consitent times in longer races, quite the opposite of what you need for hotlapping anyway. Also softer springs help with tyre preservation, again handy for longer races.

Cars with downforce work well with much higher spring frequencies anyway, so ignoring those for now, I doubt even the WR sets go much past 3Hz (UF1 excluded), which is what I suggest in the guide.

Finally, the guide is based on tips I've read about real life racing, and the tyres in LFS work reasonably different, so everything only needs to be taken as a guide, not the absolute truth.

Experimentation is the key, if something works, use it. Theory can never make up for race testing, but it can help you to choose better values to start from.

Thanks for feedback.
WR's setups are sprinter-orient, so it is normal that they use freqs about 50% higher for extremely lowering CoG. Many of them aren't good for even 10 laps race.
Such advanced in physics guys, like we are, can logically and convincingly explain all discrepancies of LFS, misses with RL )
I just was very happy with a relative results, in case they were more descriptive and can be logically explained well, rather than absolute ones, which are near randomly. And as far as it works, i'll keep that in mind.

OK, I'm new to all of this. I know what the frequencies are from reading but i have no idea where to tune them from or how. lol Could someone please explain how to do this? Thanks a bunch

There's a thread active in this forum at the moment in which Bob Smith has just explained how to calculate the suspension frequency of a car:

http://lfsforum.net/showthread.php?t=471

The whole thread is quite informative but can be summed up by saying that downforce levels don't affect the suspension frequency...the bits you probably want are currently at the end of the second page.