@ Ruboy,
I hope you can help me to find what's wrong.
Here, the story: I installed Istanbul as the old style, as I'm in a champ, still using de MP2005 (cars modified to 2006) and CSM 1.25, and, I had created the istanbul.wad and istanbul.dat before, so I need to change the interlagos.wad and .dat to istanbul to replace it.
So, I used TSM to unload the files, change them to istanbul (I have a tutorial how to do it) and replace them in my gp4, it means, I replaced only .wad and .dat files, nothing else, and I did it only on the normal track, I didn't install the hi-res version too.
As Istanbul was the next track in my champ, I started it, run the qualifying (no problems) and start the race, and, first, congratulations for the quality of the track, it's very good. The start of the race was fantastic, me and more 6 cars running almost in the same second for more than 10 laps, but, the first problem started when the cars tried to go to the pit stop, most of them crashed in the wall at the entrance of the pit. When it was my time to go to the pit, I saved the game before to try to identify what was happening there and, I discovered that if I was in the middle or left side of the track when approach turn 12, the car is pulled hard to left and at the turn 13, the car doens't make the turn, it goes to the grass and you have to go very slowly to avoid to spin. So, the problem in the turn 12, I solved running at the right side of the track, but I can not avoid the problem on turn 13, and it seems, all the other cars didn't make it, because after all the cars tried to go to first pit, I had only 8 cars running, all of the others had crashed.
So, what was a fantastic fun in the beginning, turned in a monotonous race, but, the worst problem, when it was missing 20 laps to go, the game crashed, the image stayed still and I have to turn off the PC to release it, so, I didn't finish the race.
Please, let me know what else I have to install to solve this problem, or, if you are working to try to solve it.
Sorry if some words are wrongly wrote as I'm Brazilian, living in Shanghai, English is not my natural language. So, if something was not very well explained, please asked me again and I'll try to explain better.