Dude a Cap will not help you it will just drain more power from you alternator and in the long run your alternator is just gonna die and your are going to have to replace it anyway
Blaine, 2400wrms is a lot of power for stock alternator. If you insist on a cap, then use 1F for every 1000w of PEAK power. So if your amp is 2400wrms, it might be 4000w - 5000w. Therefore you will need 5F cap. Use 12v light bulb to charge the cap. After the cap/caps are installed, monitor the car's voltage. If it drops below 12.5v, then turn the volume down till you get HO alternator. As long as you use self control, you can wing it till you have up.
issac...i got an alpine mrd 605 right now with stock electrical system and i get some blinking already just with it..i was thinking about adding another alpine mrd 605 so that would be around 1300 watts...if i do the big 3 and get an optima yellow top you think i would be ok ?