Let's assume you are generating 100 amps at 14.5 V dc and 95% efficiency. Then you are drawing about 2 hp from your engine.

Only on paper do I believe will this factor alone cost you a race.

Unless you are running a self-generating ignition (magneto) then the waning 12V may not be a great idea in general, albeit drag races are very quick, no?! Your MSD-coil will like 14.5 V much better!

One wire alternators are self-excited. You have to kick them up initially (at start-up or whenever) to kick them on. Once on I am not aware that they do not perfrom as well as 3 wire alternators. I would certainly like to see some performance curves ...............

The diode alone will not smooth voltage spikes, but then again I am not aware of MSD killing voltage spikes in a 12 V dc automotive charging system.

Kitz