Hello!
As you can see from the number of posts, I am new with LFS Before you shoot me down, yes, I did RTFM and threads, but did not understand _all_ of it. The advice that popped up in every thread was 'learn yourself', as i am trying. Some of this is simple to you, but not for a noob, so please don't laugh..:ashamed:

Does 'more chamber' (from here) mean increasing it to the negative side or to the other? As in increasing it from -2.0 to -3.0, or from -2.0 to -1.0. I am really confused with this..

And another thing, how can you save the live settings? When I drive around and change tire pressure and others, how can I save them while driving? They always disappear when I go back to the pits.

And finally, how do you know when the springs are set properly?
The car just jumps around the track (funny how you can feel it) I softened the springs and it ran smoothly, but how do I know if they are too soft?

And one more question that I hoped I would figure out myself;
I seem to be drifting on 4 wheels with the xfg. No over/understeering, just all 4wheels seem to lose traction at (almost) the same time. I have a gut feeling that this is because of tire pressure beeing too high. Am I way off or onto something?


Be gentle..

Quote from pine-fin :

Hello!
As you can see from the number of posts, I am new with LFS Before you shoot me down, yes, I did RTFM and threads, but did not understand _all_ of it. The advice that popped up in every thread was 'learn yourself', as i am trying. Some of this is simple to you, but not for a noob, so please don't laugh..:ashamed:

1) Does 'more chamber' (from here) mean increasing it to the negative side or to the other? As in increasing it from -2.0 to -3.0, or from -2.0 to -1.0. I am really confused with this..

2)And another thing, how can you save the live settings? When I drive around and change tire pressure and others, how can I save them while driving? They always disappear when I go back to the pits.

3)And finally, how do you know when the springs are set properly?
The car just jumps around the track (funny how you can feel it) I softened the springs and it ran smoothly, but how do I know if they are too soft?

4)And one more question that I hoped I would figure out myself;
I seem to be drifting on 4 wheels with the xfg. No over/understeering, just all 4wheels seem to lose traction at (almost) the same time. I have a gut feeling that this is because of tire pressure beeing too high. Am I way off or onto something?


Be gentle..

From my little experience in the setup side of LFS i can answer this:

1)Generally yes it does, afaik most people dont use positive amber, only on FE1 and oval have i ever come accross positive camber.

2) you cant save them, they are pit commands, i.e. when you pit your pit crew change the camber etc, the only thing thats "live" is the anti roll.

3) I set the springs as high as i can without them rediculously bouncing, if the bounce at the wrong times then i drop the spring rates or if it's only bouncing up but landing ok then it's a matter of dampers obviously.

4) i'd say your right with tyre pressures, but i'm no XFG expert, RWD is my thing.

Quote from BenjiMC :

.. they are pit commands, i.e. when you pit your pit crew change the camber etc, the only thing thats "live" is the anti roll.

So it was my imagination that got better lap times with 'live settings' as I did not pit when I used them :doh: lol
I truly did believe the settings were better, but I guess it was the tires warming up.. I feel so stupid right now.

lool, i'm sure your not the only one

If the springs are too soft you will find the car slow to respond to direction changes, it will roll a lot and you will need lots of negative camber to get the tyre to heat and wear correctly.

Quote from pine-fin :

So it was my imagination that got better lap times with 'live settings' as I did not pit when I used them :doh: lol
I truly did believe the settings were better, but I guess it was the tires warming up.. I feel so stupid right now.

Brake balance is "live" too.

Spring hardness is a very tricky subject. Beyond "it feels right", which is what you've done, any sort of scientific approach gets complicated fast. Start by reading Bob Smith's Advanced Setup Guide, and if you want to know more, search for "suspension frequency" in this forum. You may want to try his setup analyser too, found here.

aww.. thats a huge guide, I'll need a cup of coffee with that. Thanks for the answers!

I just read the guide and I didn't understand one part of it;

Under 'Stiffness part2' it says:
"..neutrality is found with a slightly higher spring frequency at the rear."
And the next line is;
"..to use a rear frequency 0.15 to 0.25 lower than on the front.."

First its higher and then on the next sentence its lower. Im confused, the upper part is in general or..? and the lower is for RWD? and rear freq. for FWD should be 0.15 to 0.25 higher than front. Did I read right or wrong?

Apart from that, the guide was really helpful.

Just read the whole sentence

Quote :

If the front track width is wider than the rear (as is usually the case), neutrality is found with a slightly higher spring frequency at the rear. Since all real race cars are RWD, it is normally acceptable to use a rear frequency 0.15 to 0.25Hz lower than on the front as this will introduce some basic understeer.

Higher frequency = more responsive, less grip
Lower frequency = less responsive, more grip

Wider track width = more responsive, less body roll, less grip
Shorter track width = less responsive, more body roll, more grip

If front track width is wider than rear, that means the front has less grip (understeer), thus the higher frequency at the rear will push the balance a bit more into the "oversteery" direction, in the end resulting in neutral handling.

Now, RWD cars seldom have a lack of "oversteer", thus it's not a bad idea to give it a bit of understeer by default, so to say. This means lower frequency at rear to give it more grip.


Yes, the sentences are very close together, but they talk about different things

Agh.. this is a bit hard when read in english. I really should read the whole chapter rather than translating one sentence.

Bobs analyser was helpful (thank god) to understand all this, but I think I'll just run laps with different spring settings just so I know what I am doing.
Thank you for not shooting me

Higher frequency = more responsive, less grip True, especially when the car skips over bumps instead of riding them.
Lower frequency = less responsive, more grip True until it rolls so much that the sidewalls scrape the ground and a whole lot of other possible reasons.

Wider track width = more responsive, less body roll, more grip due to reduced load transfer, reducing the effects of load sensitivity.
Shorter track width = less responsive, more body roll, less grip, increased effects of load sensitivity from increased load transfer.

Increased front track leads to understeer and vice versa due to change in the roll couple between front and rear as the wider end is effectively stiffer in roll relative to the narrow end.

Now, RWD cars seldom have a lack of "oversteer", thus it's not a bad idea to give it a bit of understeer by default, so to say. This means lower frequency at rear to give it more grip. True to quite an extent, a bit of understeer is required to allow earlier acceleration on exit.

Ah okay, truth to be told, the "track width implications" were more or less made up on the spot, so they would be in line with the spring frequency effects.

Differences in track width act like differences in roll bar stiffness. A narrower track width on one end will cause that end to roll more, so...

In the case of a car with narrower track at the rear (most common), the rear rolls more than the front, so it lifts the inside front tire, and transfers the weight to the outside rear tire. Net result is more grip at the rear, and a tendency to understeer, just like if the rear roll bar was softer than the front roll bar.