A 60 amp Denso alternator is more than enough for most race cars. You have to remember how many systems on the late model cars use and our cars only use 3-5 loads on the system. Say you have a 99 Toyota Camry with a 60 amp Denso alternator on it and it keeps up with a/c fans,blower motor,wipers,radio,lights,etc... They still charge 13.4 with everything on at idle and charge 14.5 just running a fuel pump and a few other basic items. As long as everything is wired correctly with large enough wire the basic 60 amp unit will keep your battery charged for years.
Gus