Experiments in Assetto Corsa
The theme here is making a time attack Miata or Miata-equivalent with FF and MR layouts. What is the difference in layout? How does aero improve speed and how does aero interact with layout?
- FF 63% - typical FF distribution and what "the FWD book" recommends
- FR 52% - it's easier to remove weight from the rear in a Miata
- MR 45% - just a guess at a MR CoG
Front aero has near 0 CD and CL around 0.4. Rear aero has 0.1 CD and 0.5 CL. Front aero weighs 20 kg per meter of chord, while rear is half that. For testing purposes, front was set to 0.3m and rear 0.3m.
- Naked - no splitter or wing
- Split - splitter only
- Wing - wing only
- Full - splitter and wing
Power is increased by 25% over stock. It's generally easy to unlock a bit of extra power with bolt-ons.
The tires are meant to be more like a 200TW than the defaults. The stock values of SV tires are 1.22 and 1.21. The ST are slightly higher. I think there's even more difference in lateral and longitudinal grip than AC uses. I therefore went with values of 1.3 and 1.2 for the DX and DY.
It's easy to remove weight from a vehicle, so the mass was reduced 50 kg from 1080 to 1030. Since more weight is generally removed from the rear than the front, the CoG of the FF is a little forward (52). Front aero weighs more than rear aero.
mkdir build
python3 aero.py assettocorsa ks_mazda_miata
You will have to fix sounds and "Pack data" later in Content Manger.
All of the builds are versions of the NA Miata that comes with Assetto Corsa, so you will need a standard installation of Assetto Corsa. You will also need Content Manager, which most Assetto Corsa owners already have because it makes a lot of customization easier.
The miatas.py script creates 48 vehicles, totalling about 6 GB.
(1) Unpack the data.acd file of the ks_mazda_miata into a data directory
using Content Manager.
(2) Use something like the command below to build the various experimental vehicles. I did my file wrangling using Cygwin on Windows, which is why the path below is what it is. YMMV.
python3 miatas.py /cygdrive/c/Program\ Files\ \(x86\)/Steam/steamapps/common/assettocorsa ks_mazda_miata ace
This will produce a bunch of FWD Miatas and some RWD variants with differing levels of power and grip.
(3) Copy or move all of the directories you just made to cars directory in
AC.
(4) Go back to Content Manager to pack the data directory into a data.acd
file.
(5) Still in Content Manager, replace the sounds with the original NA Miata (or something else if you prefer).
(6) You may want to modify the graphic offsets.