amp drawing too much power?

[whiterps13]

ok im running a fosgate 451s amp to my polk/momo mm10 enclosure(rated at 500rms, 1000peak), with a stinger 1 farad cap. its in a '92 240sx. when the bass hits at idle, my idle drops really low to about 500rpms, and the car shakes like a biatch. what can i do? raise the idle, deep cycle battery, dry cell? id rather not spend too much cash but this is starting to piss me off. thanks guys..

[Touchdown038]

Try raising the idle, because it sounds like the amp is drawing more power than your alternator can provide at idle.

Either that or get a higher-power alternator.

[Checkered-Member]

Either that or get a higher-power alternator.

and a red top battery

[Simmsled]

You might want to upgrade your alternator ground wire and your battery ground wire. This is a common problem though. The only true way to eliminate it is to get a higher amperage alternator and a nice battery. If you upgrade those 2 grounds though it should reduce the problem. If you had a little money laying around... go to walmart (I did say Walmart) and invest in their EverStart MAXX battery model number 1-N. I believe it is their biggest one and it is yellow. (about 59 bucks) It has 1000 cranking amps and a bunch of other impressive figures. If you upgrade the grounds and put this battery in (assuming your alternator is still chuggin along) then you will notice a definite improvement. You could also just not crank it while at idle.

The technical reason why this happens is that there is a loss of voltage and/or greater resistance to current flow. The loss of voltage is either the cause of the problem (weakend alternator or bad battery) or the result of the problem (oxidized alternator or battery ground wires, or a bad connection of those wires to the chassis). The other problem would be that you are drawing more current than your charging system can handle at a specific rpm range, so you would have to either give the motor some gas or get a high output alternator. I hope that helps.

[ayjay]

a thing about caps...

i bought a cap originally thinking that it would help take some stress off my alternator & battery... well turns out that all a cap does is provide cleaner power to the amps, and can in some cases even create more stress on the alternator... if you're just cranking your system and your cap is dropping serious voltage after everyhit, the alternator/battery has to charge both your cap and supply power to the amp at the same time, drawing way more than it normally would if there wasn't a cap... caps work well for techno music where the bass pulses and the cap has time to recharge before the next hit and gives clean bass... but for many other types of music with more continuous bass the cap will be more of a hinderance to the system than anything...

so in otherwords... forget about a cap, and just upgrade your alternator... upgrading an alternator makes the biggest difference, battery would be the second option...

[Silvia007]

Where can you find an alternator for the 240?

[Checkered-Member]

Where can you find an alternator for the 240?

Any of your local parts store should have one, it will be harder to find an OEM alternator then a higher amp one. (for my alti it is)

[InstantRice]

you can also just have your alternator rewound i don't remember what the alternator is for the 240 (switched it out fairly quickly) but it should be comparable to my old altima's which was a 105a i believe. your system shouldn't be stressing your alternator if it is around there. i've seen 100a(around there) alts running pg 1200.1's no sweet (1500w!!)