There are a lot of variables that will help . Tire and foam combinations , caster, camber, toe in/out, shock oils /springs , ride height , along with a few other details . If you are on a track that doesn`t have big jumps I`d mess around with ride height it will make a big difference . But since I can not see what is actually happening I`d say the best way to get help is to talk to some of the regulars there and they should be able to put you in the right direction . I race at a track that sounds like the same conditions and we use the same type of tires all day but use different ones with different foams towards the end of the day . Are you loosing steering in or out of a turn or both ? Are you pushing just on power or all together ? How do you have your slipper set up ?