Here you will find 3 separate spreadsheets to help with tyre development. The first, and primary, is 'TGM Generator'. While helpful, it is still quite involved to actually create a tyre. This is always going to be the first step, creating an actual testable .tgm tyre file, which is capable of being analysed within tTool (our tyre 'compiler' and analyser as it were).
The second spreadsheet, the QSA batch test generator, can help with analysis of the .tgm within tTool, by creating batch tests for your analysis. This is quite broad and free, if you happen to have tyre data, you can fill in relevant data, and have a direct comparison between your tyre and a set of data. This primarily concerns stiffness data. You can't analyse things like grip with the QSA batch tester however, as there is no friction model or thermal model within the QSA as such, you need to compile a tyre before that.
The final spreadsheet covers the real-time batch test generator. This entails a broad set of tests that can help you build slip tables, rolling resistance tables, among other things. This will help determine tyre properties and can allow you to visually see the changes you make to a tyre in a fully controlled environment. It requires a fully generated .tgm file with lookup table parameters in order to provide data.
We will continue updating this section with more information in the near future as we continue to enhance our support for modders.