Damping question

Does anybody know if Forza simulates the heating up of the oil in a damper system? I’d like to know if I should be setting dampers lower for tunes intended for cold laps (autocross, online, etc.).

Also, on another topic, is there any way to determine unsprung mass reliably? Are the initial spring rates set to kbiassprung mass / 2?

Sorry i do’nt have answers just another question ,is unsprung weight that important in the game and if so, why are light rims so cheap in p.i.

I dont know for sure on either question but I am going to say No they dont account for the heat in the dampers.

Secondly, I dont believe they account for sprung/unsprung weight, I believe it is just overall weight. So all you are doing is taking off weight from the total car. Although we know that unsprung weight loss in much more valuable then sprung weightloss.

I’m sure they dont account for heat in damper.

I think they account for the moment of inertia–how it takes additional energy to increase or decrease the angular velocity of the wheels–but I have nothing to support this. It just seems logical and not all that difficult to program is all.


  1. Oil temperature in damper is NOT simulated.

  2. There is NO reliable way to determine the unsprung masses.

  3. Initial spring rates = k x bias x sprung mass / 2? Yes, I think. I have evaluated 14 cars across different classes to see if there is a correlation/pattern. Most passenger cars seem to have a common “k” but high performance cars have different “k” and certainly the open wheel cars have their own unique “k” and Indy/F1 seem to have their own “k” (probably to compensate for additional weight due to downforce). Out of 14 cars, I have seen 7 different values of “k”.

I usually turn it down from stock then test it for feel/compliance/bottom out in testing. Open wheeled cars (KTM, Indy, F1, etc.) have different suspension geometry therefore the “k” seems to be much much lower value than the passenger cars.

Unspring mass is an important consideration for fast damper settings but FM5 does not have adjustable settings for the fast bump/rebound. Therefore I do not get too concerned about the unsprung masses.

I am still struggling to understand the meaning of settings of 1~14. Why 1~14? Why 14 specifically? Why not . . . 10? What does 1 & 14 represent? Is it a relative damping number (relative to spring rate) or is it an absolute number (meaning 7 is same damping force no matter which car)?. I think it is a relative number (only applies to one car at a time) but still no idea why the maximum has to be 14.

Interesting, The k values will be different due to the cars aero dependency i would have thought? Since ride frequency and aero are related in the real world as in general the more aero the more pitch sensitive the aero platform is and the stiffer the springs have to be.

IIRC that’s right but it was a while ago that i did it so correct me if i’m wrong.

Are you referring to k = spring constant or k used in this thread?

k used in this thread I think is “multiplication factor”, not THE k used in spring calculations.