[filmsculptor]

hi 
I'm  new to this hobby so apologies (if like on most hobby forums) this question has been asked many many  times...
anyhow  bought a scalextric digital set recently , that has the 4 channel  silver digital powerbase 
done the usual thing  and already doubled the size of the track  only to find its now lacking in even power and has little chance of powering 3 or 4 digital cars at once .it doesnt..
So have attached  three sets of powertaps to the track , and while this has helped , its still lacking in even consistent power. 
two questions 
1 should the powertaps be connected pretty much one to the next , till you've got all the way around the circuit , or can they be randomnly connected from a strong spot to a weak spot thus strenghtening the weak power area
2 with the sort of power base set up i have is it and (how) possible to connect a second power supply  to the track ?
thks in advance