retraining exracehorse

Question
I have an eight year old OTTB.  I have been trying to train him with the assistance of an instructor.  I have tried about 6 different bits and finally put him back into a snaffle and would like to start over.  He does not know what "whoa" means once he gets going.  He gets faster and faster.  Half halts mean nothing.  He lunges well, has good ground manners.  I even trail ride him and he is great as long as we stick to a walk.  Help please

Answer
This is not going to be a fast fix at all.   It will require patience and understanding.

To a racehorse, usually pressure on the mouth (ie pulling the reins) means  he has to go faster.  I had this with my ex racer a long time ago, and found that the best way to stop him was to let the reins go slack and then  he would stop.  Its not a remedy for the fainthearted and is best practised in the schooling arena first before trying it out on the  trail!

The other alternative would be to try him out in a Hackamore bridle, but again please use this with caution, too much pressure can damage the horse completely, too little and he will ignore you.

When he starts to ignore you then the best thing to do is to halt him completely and then continue when you are ready, again it requires patience and constant reinforcement.

Once he has done as you ask him then plenty of praise is the order of the day.  you may need to ask him a few times  but he will soon realise that in pleasing you then he makes life easier for himself.

Ask your instructor for help  in overcoming this problem, training an ex racer for another  discipline is harder than people think, but with perseverance and dedication they make great riding horses.