[punkin]

Hello all,

Does anyone have information on what a typical 68 firebird power requirements are? This would be for headlights, dash lights, heater blower (no AC, no power windows). Unfortunately, the car is torn down now and I cannot measure it.

I'm trying to figure out what size alternator to go with. I've added dual fans, EFI, MSD, fuel pump, electric water pump and 4L80e with controller. I'm roughly calculating these items to draw around 120 amps worst case but I don't know what the rest of the vehicle requires.

Thanks

[Scott65]

Mine is close to the same as yours, but I don't have the electric water pump, or electronic transmission. It draws 54 amps with everything on. Measued with an amp clamp. That is steady state. The fans and water pump could have spikes on initial start up, but that's hard to catch on a meter. My car operated fine on a 94 amp alternator. However due to pulley sizes, and max alternator rpm considerations, I went with a 150 amp alternator and oversized pulley. It supports all the electrical load, and won't get revved past 18000 at max engine rpm. 18000rpms is max on most GM style alternators. Do your math, and size pulleys accordingly. I exploded the plastic cooling fan on a 12si alternator to learn this lesson... Right through my fiberglass hood, and cut the upper radiator hose on the way...

[killakev]

I have a replacement 65 amp alternator - no AC, CVT power top, HEI distributor, modern radio system - No issues

[OCMDGTO]

Call Powermaster, they answer a phone in English and are very helpful

[padgett]

Thought "Powermaster" was a GM electric power brake used on Grand Nationals.

[punkin]

Thanks everyone!

[AG]

I have a Mark VIII fan (44 amps running), an electric fuel pump, water pump, MSD box, FAST AF gauge on my race car which draws about 70 amps total and use a 100 amp alternator. I use a 4 gauge wire from my alternator to the battery in the trunk.