Car Setup Issues

Okay this is my first season on Ace Difficulty.

I edited my gear ratio i think it was for a race so i wasnt being swamped on the straights and basically the default setups for each track are gone. So when i travel to the next race it carries over the setup changes i made. Im not very good at setting up cars but understood the gear ratios enough to make myself faster on the straight. Now im stuck as i try to make changes and find myself most of the time 16th or lower but on the right times for that position or 3 seconds off the lead and a further 1.5 seconds off 21st place.

HELP! why has this happened

Your problem could have 2 very different reasons:
1) car setup
2) Computer Car (CC) setup in the MD file (a text file into every track to setup a lot of values related to the track itself, CC and your car)
So first of all, let me know:
- what tracks are you driving on? I mean, the original ones or custom ones?
If you are using custom tracks, maybe the CC grip and/or power factor is too high, and you have to change a few value. We will analyze it after you answer me.

Now, about the setup. Of course, every track needs a different setup, so the setup you use in Monaco is totally wrong for Monza, just to have an example.
But i need another info: how do you play Gp3? with a steering wheel (maybe a force feedback)? or with a joypad or the keyboard? And how many helps you use? This info is very important, because if you use a keyboard we can use a basic setup, but if you use a wheel, we must use even the level 2 advanced setup menu to set the differential, the packers and the dampers.

So let me know.
Bye, Claudio.