LFS Forum - Spring rate at wheel

#1 - Antsa

Spring rate at wheel

Fri 23 Mar 2007, 10:44

Just a quick question. Should I use "Spring rates at wheels" or "Spring rates" if I want to use real values for LFS cars?

#2 - Gentlefoot

Fri 23 Mar 2007, 10:57

Quote from Antsa :Just a quick question. Should I use "Spring rates at wheels" or "Spring rates" if I want to use real values for LFS cars?

Do you mean wheel rates vs spring rates?

You will have to stick with spring rates because we do not have enough information about the suspension of LFS cars to calculate wheel rates. To do that you would need to know the SAI amongst other things. I don't believe that information is available.

#3 - Antsa

Fri 23 Mar 2007, 11:21

Yes, wheel rates..

So, do we need motion ratios of LFS cars or something like that?

#4 - Gentlefoot

Fri 23 Mar 2007, 11:41

Quote from Antsa :Yes, wheel rates..

So, do we need motion ratios of LFS cars or something like that?

I think there are two ways of calculating wheel rates.

If I remember rightly wheel rate is spring rate over motion ratio squared yes. I think you'll have problems calculating Motion Ratio too though

You need to know the wheel travel and the damper travel to work this out.

Because the angle of the damper effects the wheel rate and also the distance of the damper from the hub you need to know the Steering Axis Inclination and supension layout. With Mcpherson strut the strut will almost certainly attach directly to the hub so that distance is more important on double wishbone setups.

I've got a book at home with a complete example for calculating wheel rates. It wasn't that simple and there are a lot of pieces of information you need that I don't think are available in LFS.

#5 - Antsa

Fri 23 Mar 2007, 12:19

Ok, thanks for the information.

#6 - KartRacer

Fri 23 Mar 2007, 18:33

To get Wheel Rate:

SW/ECR=WR

SW- Net corner weight
ECR- Effective Coil Rate
WR- Wheel Rate

#7 - Bob Smith

Sat 24 Mar 2007, 11:37

Quote from Gentlefoot :I've got a book at home with a complete example for calculating wheel rates. It wasn't that simple and there are a lot of pieces of information you need that I don't think are available in LFS.

If you can find out and share that with us, that would be great. I can ask Scawen to add those values to the .bin outputs so that people like myself can model the cars more accurately.