I didn't slow down any with the alt. Might even be a little quicker. Less weight as you only need one battery.
I'm sure somebody on here can convert amps to watts to hp. I think it takes something like 1.5 hp to make 55 amps. And to turn my alt fast enough for the full 55 amps takes 4000 + rpm. Full voltage at 1500, but you really have to spin one to get full amps.
I prob gain that 1.5 hp back by running full voltage to the iginition. With no alt the voltage starts dropping instantly from fully charged. MSD will tell you that their sytems are designed to run best at 13.5V. That's what it's getting with the alt.
For a race car go for it, no reason not too. I have a single 850 CCA battery. Slow charge it overnight at 2 amps the night before a race. I can then go to a two day race and run all weekend and never need to charge it. That's even with running the fan and water pump in between rounds for cooldown. If it's really hot ,95°+, and I have to run the pump and fan much more than normal, I will charge the battery a little every now and then.
I run an EastCoast super mini on my cleveland. I am using stock brackets, and am going to put a Moroso pulley on it this year. As for it slowwing the car down, it's actually a little quicker with the alternator on than with it off. Like Dave said, MSD likes voltage, if the voltage starts to drop at all, there goes your consistency. Add the fact that most racecars are using alot of electrical items, it's actually pretty smart to use one to make sure the battery stays fully charged.
Thanks guys! Looking forward to making the mav even more consistent. The last race day, in time trials it went 6.871 @ 107 mph 4 times in a row, so I dont know how much more consistent it can get. Dead battery kept me out of eliminations. Got to the stage lanes, and....nothing, would just click. The generator quit charging, so the wal-mart battery charger wouldnt charge the battery in between rounds.