If he's saving those antics for the track there would be no point in getting the nitrous in the first place, since it may only see track duty once a year. Most people i know that say track once a year mean never.
Powerful light cars take alot of practice to drive. His car sounds like a handful from the get go.
Clement makes a point, how much faster on the street is the car going to be with 125 shot? Probably none, lack of practice with that extra power (with an SC you drive it every day the same way, so you are always practicing) coupled with tires that won't be warmed up from a burnout probably will yield worse results instead of better.
Nitrous just has no place in anything but organized racing (whether it be track or street).
The guy with the most power doesn't always win the race.