I have two 12 inch spal extreme performance cooling fans and when they initially start up they sometimes can stall the car.
The fans get the power straight from the battery. Can I put an audio capicator I between the fan and the battery so the car won't stall when the fans start up?

 

What kind of battery do you have?

 

You'll need to add some type of resistor for the capacitor to charge

 

Something doesn't sound right. The battery should easily provide a couple hundred amps, plus I think the alternator is rated at 90 amps. I can't imagine a pair of fans drawing so much current it would drop the battery voltage far enough to cause a stall. I mean, the starter motor is MUCH more powerful than your fans and when it's running the ECU has no trouble operating normally and firing the injectors and the ignition coils. I think something must be wired wrong.

And I'm wondering why you need such powerful fans? I live in the South, running 350WHP and the stock cooling system, never had a problem. I've seen cars with much more HP running the stock cooling system too. Do you spend a lot of time in traffic jams in 100° weather?

To answer your question, an audio capacitor would likely help, but I think you should confirm there is no wiring problem first, or have your battery tested. Also, the comment about "You'll need to add some type of resistor for the capacitor to charge" only applies when the capacitor is first installed. The resistor should never be left in the circuit once the cap is in place.