Race car mystery-Help us solve PLEASE

Ok I'll do my best to explain,The thing that had everyone scratching there heads was when we went out for a run the batt's were at 80-100 percent charged,Zach would make a run and we would put the charger on and the batt's were at 30 % ???? so we started to inspect things between rounds and the issues kept happening.We found a burned out diode in the alternator,so we removed the alt. all together and the problem went away,We think what was happening was since the diode was burnt out the alternator was working in reverse and massively stealing power from the batt's so voltage got low and the ignition box was starving for power and hence we had no high rpm spark and broke up,the issues was completely removed once we took the alt. off,he was once again going thru the traps at 7600 and pulling hard on the back side of the track,We ran a couple 10.5's in 98 degree heat and 85% humidity so in clean air we should be right back down to our 10.3's we ran originally.so lesson learned and i hope if you guy's ever have something like this happen you will remember this thread--Steve