""Why are you running a "Race Only" unit in a street car? It's no wonder your having problems!""

In my case, it raised the voltage to the coil since it was always 13.5 volts. My stock regulator would put out lower volts and I would get lower volts at the coil as a result. At that time, I was trying to keep as much voltage at the coil with my old ballast setup that I could get and it worked for that as long as I did not use any of the accessories (lights, wipers, etc like a race car would in the pits).
I have since removed the ballast system and gone with a 12v coil. Since I am using more accessories now than before, the blue regulator is now my backup to a NAPA stock replacement unit.