I'm trying to figure out the best solution for a drag only car for electrical system.I'll have a load of 60 amps w/ all the fans , pumps etc. running. Going down the strip I'll have just the Fuel & waer pump plus the MSD running so maybe 30 amps.Whats the best set up?? One Battery or two? Alternator or not ? What size alternator? I tried an earlier post with not much response. Any help will be appreciated.

1 good battery(700cca or so) and an alternator will do the trick. I ran two batteries and no alternator for a while and it sucked. I can't remember the letter codes but the type from the 1980's to now work great.

I'm with Dragn, I ran 2 batteries, No Alt and a Magneto. Worked great to just go out play at the track for a night, but as far as racing.. it bit me a few times.I suggest atleast one good batt. and an Alt.
Duane

twc i see guys run two batteries all the time with no altinater and charge between rounds with no problems personaly i run one 900 cranking amp baterry and an high amp gm altinator and i still charge my baterry in the latter rounds to keep from having a problem if you think about it you dont ever run the car that long of a time to really charge the batt. between rounds and i always cool the motor down with the water pump and fan after a run

How 'bout this? Big alternator (100+ amp)to ensure peak performance with max load (fans, fuel, etc.)Two batteries (700 CCA each)wired in both parrallel and in series. 12 volts with lots of amperage to everything but the coil(for starting, fans, fuel pump, etc.) 24 volts to the coil (and maybe the starter) for faster saturation to ensure high RPM ignition strength. The problem with 16 volt systems is that you need to buy over-priced batteries, alt, charger, and only the starter and the coil can stand the 16 volts, so you have to reduce the voltage to other components with resistors....but the starter and coil will take the less expensive 24 volts, and both will outperform 16 volts at 24 volts.

Something to think about, see you at the track.

Gary

You can't wire the batteries in series and in parallel at the same time. You would need a 24V alternator and something to force the batteries to share the voltage so they don't become unbalanced with one overcharged and the other discharged.

Anyone have any data on the spark quality vs the applied voltage? Does only 11 or so volts affect the spark output of say an MSD ignition box?

I've read that you could use a 10SI or 12SI alternator and just disconnect the 2 smaller wires that go to the plug-in connection during the run to disable it. That way, you can be charging right up until the run and then charging again right after.

Peter

Good batt and a 140 amp alt will do the trick.I run nitrous,bottle heater,two fans and two fuel pumps with a 140 amp alt and a good batt.