Help : My Engine RPM's Drop

[pioneer 10+ year member]

i have noticed when the car is at idle on neutral the RPM's are at about 850. When the bass hits at higher volumes it drops to about 800. Can someone tell me exactly why this is happening and what i can to properly fix the problem ?

Amp : JBL 1200.1 being fed 4 gauge wire running at 4 ohm ~600W rms.

Alternator : 90Amp

Thanks

Click to read more...

 

[tommyk90 5,000+ posts]

Probably has to due with the fact that when the bass hits your electrical system strains to power the amp, which could draw power away from the electrical system, such as ignition components. I know there are probably other reasons, but that it what i could think of.

 

[maylar 10+ year member]

It's simple: The amp is taking power from your engine. Same reason your idle drops when you turn on A/C - it's extra load.

746 watts = 1 horsepower. The electrical power comes from the alternator, which in turn is driven from your motor.

Get a bigger engine or a smaller amp

Seriously, I dunno of any solution.

 

[pioneer 10+ year member]

well its a very small drop in RPM's

would a 1 farad cap help ?

 

[awalbert88 10+ year member]

No, a cap would strain the alternator harder, and put even more load on the engine.

 

[Jdg784 10+ year member]

You really don't need to worry about it, such a small drop won't hurt anything. Best you could do is get a bigger motor..or smaller amp like was posted earlier.

 

[pioneer 10+ year member]

i dont think it's actually 50 RPM's i'm loosing...its less

at idle its jus above 800 and when the volume goes up it drops to 800

 

[natdew_jr]

when your bass hits the amp draws powe from the battery and alternator. To fix the problem you can get a bigger alternator or try a adding a copacitor.

 

[eengrms 10+ year member]

Originally posted by natdew_jr when your bass hits the amp draws powe from the battery and alternator. To fix the problem you can get a bigger alternator or try a adding a copacitor.

To fix the problem? This isn't really a problem, it's pretty normal. No matter how big your alternator is you're still going to see a drop in available power to the vehicle when the amp is cranked. Yes a bigger alt will creat less of a drop, but there will always still be one. There is nothing wrong with your car, or your alternator. Just rev the engine or turn the sound down a notch or two when idling if you're that worried about it. As stated before a cap will not help, not at all. All it will do is give your amp a little more power when needed, but the alternator will still be pressed to deliver extra juice, and probably more often.

 

[Jacobs 10+ year member]

Ok probably not really a solution to your problem, but when my bass hits sometimes my tac goes up sometimes down.... along with all my other gauges just from the vibration!

 

[pioneer 10+ year member]

Originally posted by Jacobs Ok probably not really a solution to your problem, but when my bass hits sometimes my tac goes up sometimes down.... along with all my other gauges just from the vibration!

hmmmm vibrations huh ?

i didnt really think about that

someone told me i shoudl get a gel-cell battery to solely deliver power to the amp

or perhaps the cap to stiffen the voltage

 

[Jacobs 10+ year member]

IMO upgrade your alt before you worry about a second battery. Im dont know much about second batteries but wouldn't u have to charge that one with your alt too? so it would just put more strrain on your alt... from what I understand second batteries usually only help for the first little while your car is running or it will help your system play longer when your car is turned off. But get a second opinion on all that!

 

[maylar 10+ year member]

No matter how many batteries, alternators, or capacitors you have the power to run your system eventually comes from the engine. Watts and horsepower, can't change that.

 

[pioneer 10+ year member]

well i was plannin to get a lightning audio gel cell battery

or even a batcap 300

but i dont know much about batcaps and not much ppl use them

 

[pioneer 10+ year member]

Originally posted by maylar No matter how many batteries, alternators, or capacitors you have the power to run your system eventually comes from the engine. Watts and horsepower, can't change that.

so what will be the best most economical solution ?

btw do i have a problem at all ?

if not...then i wanted something to give the amp a constant supply of juice