I could you suggest you to go out there and check if you can reach the same performance levels you had back in the 90'ies.The first time I tried GP2 in the 2010's, playing the regular/original game before trying any modding, I tried to qualify at Spa, changed the set-up to what I thought was something similar to what I used 15 years before, and I was 22nd... it took some practice to get back
