2 alternators

[munkee]

I am going to install a second alternator to charge the battery pack for my ESC. Can an alternator spin in either direction or is it CW only? Thanks.

 

[SHOZ123]

Yes they can spin in any direction. But don't know why you need two of the parasites. I can guarantee you that you are not using the one you have to it's fullest capacity.

 

[masho95]

Look up ^^^ ESC = Electronic SuperCharger if I'm not mistaken. They will suck up juice like no tommorrow and you should definitely run 2 alt's.

 

[Hack]

Chris, have you thought of removing the AC pump and installing it there? Tons of room down there.

 

[munkee]

I have thought about that but I would like to keep the A/C working since it's the daily driver. I was going to use one 200 amp unit in place of the stock 90 amp but I was told by local shops that the stock alternators are at their physical limits to rebuild them that high. Plus, I kind of like the idea of keeping the charging circuits for the car and the ESC separate. I have been trying to find figures for the amount of parasitic loss an alternator creates but I haven't found anything yet. Anyone know? I will wire the second alt so that it only charges until the batteries are full, then shuts off to cut down on parasitic loss. Knowing that it can spin either direction makes things a lot simpler.

 

[SHOZ123]

So what is the current draw and how many amp hours is the battery pack rated at?

What does one of those ESC weigh?

 

[Hack]

I have been trying to find figures for the amount of parasitic loss an alternator creates but I haven't found anything yet.

Honestly, I think that in terms of horsepower it is going to be pretty low. It is pretty widely agreed that underdrive pulleys on V-6 SHOs serve more to prolong the life of the accesories than to make horspower.

I will wire the second alt so that it only charges until the batteries are full, then shuts off to cut down on parasitic loss.

I would definately wire it as you have stated, as overcharging the batteries would not be good. On the otherhand, unless you install a clutch, like on the A/C pump, the parasitic loss will still be there.

I am eagerly awaiting your results. From what I have read, I think it is going to be an impressive setup. If my main goal was drag racing, I would be following in your footsteps.

 

[munkee]

SHOZ123, the ESC 550 draws 680 amps at 24 volts. In case you missed the thread on here before that got locked, check out www.boosthead.com for a product description. I will be using 6 Hawker drycell batteries rated at 535 CA and 13 AH apiece. The ESC is an eaton supercharger driven by 3 24v starter motors, to be used in 15 second bursts like nitrous. If I remember right, the ESC is about 60 pounds. The batteries are 11 pounds apiece. I have a pretty good idea of how I want to set the system up but I am open to any suggestions or ideas from anyone. yellowSHO, I agree that this would probably make a very good dedicated drag car setup. You could have 12 psi of boost from idle to redline with this system. If I were doing a drag car setup, I would probably go with your previous suggestion of removing the a/c and putting the alternator there. I pretty much have all the parts ordered now, just working out the kinks until after vacation in july. Then I will start the installation. I will be sure to keep everyone updated.