Hello everybody. Once again, I need you to explain me some things in order to get the best possible mod. This time, I am working on the .pm file of a rFactor 1 mod, but I know that it works the same way for rFactor 2, that's why I ask here (on the rFactor 1 forum it's dead). I have many informations about the suspensions, including each element's mass (for the spindle I have the mass for the separated parts) and position, except for the spindle (I don't know where the center is located but I can calculate it). So it should not be too complicated to write the position lines. But I don't know how to calculate the inertia for the wheels and the spindles. I think it is all that I need to finish it. I gave a look to the rF2 physics calculator, and I got some values entering what I already have, but I do not understand how it is calculated, there are some fixed coefficients or something like that...Isn't there an easier way to make it ? Because, once again, I will need to explain how it was calculated for my thesis. It also seems like the mass written in the files for the spindles are more complicated than that. They seem to be a combination of all unsprung non-rotating masses, but it is really really strange... One more thing for which I need help is the Undertray. English is not my native language so I don't understand all explanations about it. Is it what I would call the "flat bottom" ? If yes, I really don't see why there are 10 values and parameters like spring rate that are never explained (or at least it is not explained how to find them). I hope someone is motivated enough to tell me that, as I think I should have finished this part (the Undertray can wait a bit more) for tomorrow evening or Sunday morning in the worst case. If you need more data, just ask and I will give it (I prefer in PM but I can also do it here). Thanks in advance !
Inertia is in kgm² units. Think of it as the infinite sum of distributed point masses in relation to the rotation axes. Easiest way is to solid model, apply your material properties, and pull the inertia from the program. Otherwise, simplification of shape and integration are required. Inertia is not very intuitive, knowing how to use calculus to find it for simple shapes help further understanding. Why does it seem strange that the non rotational unsprung masses are simplified into a single solid body? Yes the undertray is the flat bottom of the car. The 10 values for the undertray correspond to shape and have a particular order. The first four I believe are where ride height is measured. FLRH FRRH RLRH RRRH F FL F C F FR M FL M FR M RL M RR The spring, damper, and friction values for the undertray define the reaction when impacting objects.
Hello, thanks for your answer. between the time I wrote this post and the time you answered me, I had found more explanations about the Undertray. Abouti inertia, I know what it is and how to calculate it for simple shapes, but for the upright, the hub and so it is obviously much more difficult. First because I don't have all the dimensions of the spindle, and I also don't know what material it is made of. I will still try to look at the official spreadsheet but it is not that easy. I will work hard to find it but if I don't get it, I will take valuers of a close car...Thank you and have a nice day !
