Dyno testing years ago on a motor with battery only(two fully charged dyno batteries) feeding the MSD 7Al2 ignition made less power than with a alternator mounted and working on the same motor twenty minutes later shruggy(2 or3 HP,CRS)
I saw the same thing at the track with my alternator gutted by bypassing the blue Holley fuel pump using the Carter NASCAR Hemi mechanical fuel pump only, MSD race ignitions need and like good voltage and current work
As already pointed out the cars current requirements will have a large effect on any testing, especially with large draw electric water pumps and fans work

Last edited by Cab_Burge; 08/15/19 02:10 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)