I am looking at getting a new system (800 watts RMS) and I think that will be beyond the limits of my current electrical system. Will I need a higher power then stock alternator? I already have a 1.0 farad cap. If so, what kind, how much, and where can I get them. Thanks a lot.

PJ

 

don't hide from me!

PJ

 

I have one. Ohio Generator, actually it's on it's way back to them right now. But it will be back in the Max soon enough. But, for less than 1000-1500 watts RMS I wouldn't bother. The 1 farad cap should be plenty to stabalize your voltage. When just running the two amps I have hooked up now (700-800RMS) the stock alt is plenty strong. It's the MTX 1000D in the box in my basement that provoked the new alternator install. Hopefully next year I'll upgrade atleast one of my current 4 channel amps to something a little stronger. All depends on the overtime allotment.

 

I 2nd that. 800w is nothing!

Actually, depends on what kinda amp that 800w is coming from, thats more important.

Class T or D will draw a lot less than class A/B.

 

will require a higher amp alternator. I guess I'll see how it all turns out when I get the new stuff hooked up, then I'll be able to see if I need anything else. 800 RMS is nothing? Going to be pretty damn loud to me!

PJ

 

I 3rd that

Maximadave

 

800 RMS is not a constant supply. It's the max continuous the amp could send if fed a constant max input. So unless you only listen to your system at max volume with a CD that has no volume variation your actual average output will be considerably lower. Besides, the honda civics and VW's that normally get multi sub installs only have about a 65 amp alternator. The 4th gen Max has a 110 amp alternator. My average current draw with one of the least efficient amps - PG ZX475Ti and my old Alpine V12 50x4(although more realistically it is 75x4) - is about 10-15 amps. PJ, how are you coming up with the 800 WRMS number? What are the fuse ratings on your amps?

800 W RMS at 50% efficiency = 1600 max Watt draw
1600W/14V = 115 amps max for maybe a milisecond

The cap supplies the additional voltage needed at peaks. There is no need for an alternator upgrade, but if you want to spend between $350(mean-green) and $1500(stinger/Streetwire) on equipment you don't need and then have it installed, go right ahead. If you want to hear my system with over 800 watts and the stock alternator come over quick before I reistall the OG. I have a small amp I could hook to a sub to increase the output to about 850 RMS - not max. I am damn sure you won't see any light dimming.

 

what about if your using an under drive pulley couldnt the high amp alt keep power levels constant?

 

The underdrive pulley is an electrical nightmare. Your stock alternator starts developing decent amperage just above idle with the stock pulley. But if you halve the number of rotations in relation to the crank you will have to be at double the RPM's before you develop the same amperage. The upgraded alternators develop more peak current at normal engine driving speeds but the current development is much lower at lower RPM's. In order to develop this power at the upper RPM's a sacrifice is made in the lower RPM's. Meaning that you probably have less power at idle than with the stock alternator. With the underdrive pulley you might be lucky to have enough current to get a spark to the end of the ignition coils.

You would probably have to get an alternator designed to produce max current at low RPM's, or at idle. But check into this with the alternator companies. These alternators probably have rotational limits. I know that Streetwires' advertise alternators that produce max current at low RPM's.