the problem with magic data is that it depends on what performance and physics you are using, as well as various other factors.
i suggest you have a look at changing it yourself. Get CMagic4, and with it, you can extract the magic data from each dat file. From there, if you want to change lap times, you will want to look at the 'track grip' section, and also the setup, which adjusts top speeds of the AI cars.
X (@ed24f1)