Btw hints for those who want to play this game in the future (maybe only Akoss Poo):
"Proper" settings of GT1 (the one I use at the moment):
Ride height: ~15%
Stiffness, brakes and other scales: 50%
Downforce: front 60, rear 20
Tyre pressure: front 45, rear 40 (obviously slicks)
993 Turbo seems to be a good alternative (not on damned fast speedways, like Autobahn or Zone Industrielle). Close ratio gearbox is essential on slower tracks e.g. Corsica and Schwarzwald. Optimal settings are similar to GT1 (except gear ratios, you can't modify them here).
Give a try to these parameters and you will beat your old records easily.