Camaro B Class Profile Help


I have just started driving the Camaro B Class car and I am using the same profile as my GT cars initially, I am getting good feedback on the straights, but as soon as I start cornering the feeling just disappears and it feels like a shopping trolley, only to return when I get back on the straight. I am using a 350mm Deep Dish rim. I am using 20nm Wheel Force and 45nm Max Force in iRacing with 20nm Overall Strength in True Drive. I have tried adjusting settings in True Drive, but it doesn’t make any difference. Is it the car, the size of the rim, any help would be appreciated.