I have an of the track horse too, and it seems to harder I pull (for example she gets hot in the canter and a half halt just doesnt cut it) the faster she goes. She rides really nice in soft hands and LOVES being ridden in my bitless or my halter. I ride in a really soft bit and just take the contact as I need to.
Also , if he's recently from the track, he will need about 6 months to cool down. My mare was having problems then she injured her stifle, it took about 6 months of gentle lunging and lots of loving to get her quiet. Now, we dont have fits often.
Hope this helps!
If you love something, set it free
If it comes back it's yours
If it doesn't, it never was