Maximum length for 1/43 Carrera GO!!! (Analog)

Hello all,
Got some Carrera GO!!! 1:43 (Analog) sets for my Grandson for Christmas and we were wondering what is the maximum length that I can extend the GO!!! track. Power supply is standard GO!!! transformer: 14.8 V, 2 x 350mA. I plan to use Power Taps every 15 ft, but how far can I push this and still get performance. Is there anything else I can do (bigger transformer??) to increase the power and still stay Analog at this time? Any hints, tips, etc would be much appreciated.
Cheers.
Got some Carrera GO!!! 1:43 (Analog) sets for my Grandson for Christmas and we were wondering what is the maximum length that I can extend the GO!!! track. Power supply is standard GO!!! transformer: 14.8 V, 2 x 350mA. I plan to use Power Taps every 15 ft, but how far can I push this and still get performance. Is there anything else I can do (bigger transformer??) to increase the power and still stay Analog at this time? Any hints, tips, etc would be much appreciated.
Cheers.