I did a test.
I took a car very well balanced i`m tuning now, Ferrari california 550PP sport soft.
Put sport hard tires on it and went to Nurburgring GP/D. I know perfectly the track and i´m able to drive on it at the speed the tires allow with the tune, staying on the same good driving line during each turns.
1 test : lap with ballast position 0 and 0 kg ballast, stay all the test with this ghost.
2 test : lap with ballast position -50 front and 0 kg ballast, the direction is more heavy , the car show more under-steer, the ghost at same speed stay more inside the corner to apex, out corner the car show more over-steer tendency at acceleration.
3 test: lap with ballast position +50 rear and 0 kg ballast, the direction is lighter and more responsive with more eagerness and front grip ,can reach the apex more easy, but the car can over-steer a little if to fast on entry. Out the corner the rear is more planted and you can accelerate earlier without over-steer.
4 test: i repeat the stage 2 and 3 with 20 kg ballast and i feel the reaction of the car the same , but with more projection for the same tendencies.
My conclusion: Moving the beer box at position +50 or -50 with 0 kg ballast is the same like adding 20 kg ballast more or less, but without the handicap of some more extra KG.
Some cars needs ballast more than others.
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