[Wally]

A spring has a frequency which is a standard way of comparing it's stiffness - e.g. 2 Hz. Road car springs often have frequencies around 2 - 3 Hz, while race cars like the FR3.5 are much stiffer, at 5 - 8 Hz.

AC's Car Engineer app shows you these spring freuquencies, front and rear. If you can't see the Car Engineer app, you have to edit steamapps\common\assettocorsa\system\cfg\assetto_corsa.ini to set ENABLE_DEV_APPS=1.

If you load the default FR setup without ballast, the spring rates are 8.1 Hz in the front and 5.4 Hz in the rear. Now get on the practice server and set your ballast with the following commands:

/client_list (find out which car number you are, e.g. 11)
/ballast <car num> <ballast>, e.g. /ballast 11 46, for 46 kg

Now look at your spring rates again. Because your car is heavier, the spring rates have gone down (the springs are compressed more). If you want to keep the same spring rates as the default setup, you'll need to stiffen your springs. Raising front and rear springs by one click gets the spring rates back to 8.0 and 5.3, which is close enough to the default setup.

Stiffening your springs also raises your car height, so you might want to take a few clicks back off the front and rear ride heights to compensate for the stiffer springs.

[Guybrush Threepwood]

Ballast also effects the balance of the car, so depending on your height ratio front to rear will increase over or under steer.   It puts more weight on the tyres so they will get more temperature and wear, and also change the natural camber values.  The weight transfer laterally will also be increased so anti roll bars need to be changed.    The damper rates, similar to spring rates will also be effected.

That's what I've found anyway.   With high ballast + full fuel, increasing the spring rates by themselves to a level similar to low weight would make the car loose a lot of mid turn grip.  You also need to be mindful of the balance of the car as just because the springs have been increased by the same amount,  doesn't mean the car will have the same balance.

[Wally]

All true... I mainly wanted to show how you could use the Car Engineer app to ”dial in” the same numbers as before. The app also shows the damper ratios (< 1 means underdamped, 1 means perfectly damped, > 1 means overdamped), so you can also use it to make your dampers behave the same for any weight.

[Freezer]

Now get on the practice server and set your ballast with the following commands:

/client_list (find out which car number you are, e.g. 11)
/ballast <car num> <ballast>, e.g. /ballast 11 46, for 46 kg

Bit new to these commands.  Am I typing them into the chat window?  Couldn't get any response.

[grat]

Yes, Freezer. In the chat window. But first you need to write /admin "password" where the password is... the usual, and then /ballast 11 46.

[Wally]

Also, only works online.

[Joe]

This is all beyond me, I just went with the base setup first race with no ballast, then the base setup again with some ballast and felt like I did okay both times. I guess maybe when the ballast gets to a point I'd notice the handing is different?

[Gratulin]

This is all beyond me, I just went with the base setup first race with no ballast, then the base setup again with some ballast and felt like I did okay both times. I guess maybe when the ballast gets to a point I'd notice the handing is different?

Same here Joe. I think they change the base setup to make it 'loose' or 'overteery' which then makes it more sensitive to ballast. Also, they are faster to begin with so the extra ballast might just bring them back to being mere mortals. Maybe that's why all the 'grumbling' about ballast

[Wally]

It's fun to learn about spring rates and damper ratios though, isn't it?

[Bacchulum]

I still want the Car Engineer to show low & high speed damper ratios separately as well as roll centre (which Guy pointed out changes) and also aero centre of pressure.
Basically all the details nKPro had.

[Rolz]

Thanks for this Wally/GB - still very much a newbie here so will check it out for round 3