What's the most powerful amp I can use without modifying my electrical system?

[grampi 10+ year member]

Is there a way to determine the most powerful amp I could use in my vehicle without having to upgrade the electrical system? Doesn't amp efficiency need to be factored in and how do you go about finding out how efficient a given amp is? I don't want to have to spend a bunch of moola on stuff like H.O. alternators, caps, additional batteries, etc.

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[Johnny Drama 5,000+ posts]

Need your car make and model and alternator specs.

 

[grampi 10+ year member]

Need your car make and model and alternator specs.

'99 Corolla and I think the stock alternator is rated for 80 or 85 amps.

 

[dvrmstrng 5,000+ posts]

i try and find a nice effecient amp that puts out around 1k.

 

[grampi 10+ year member]

i try and find a nice effecient amp that puts out around 1k.

I don't what spec for a given amp I should be looking at that tells me how efficient it is.

 

[memphisspl 10+ year member]

Efficiency actually won't be that big of a concern. It seems like 90% of your monoblock sub amps nowadays are class D topology. Class D yields somewhere between 70% and 90% efficiency. That 20% difference in efficiancy isn't going to make or break an electrical system. Besides, most manufacturers overrate their amps efficiency anyway. So, throw efficiency out the window. It's not an important spec.

With that car, I wouln't even consider anything over 500 watts RMS if you want to do nothing to upgrade your electrical system. Going with something as large as a 1000 watt amp will require an upgraded battery and upgraded factory grounds at the least. Anything larger will require a high output alternator.

This all depends kinda depends on your taste in music. I assume you listen to rock or rap, in which case will be the most taxing type of music you can listen to, so this is where my recommendations arise from. If you listened to primarily classic rock, classical music, country, something a little more tame, you could get by with a larger amp, but I doubt that's the case.

A 500 watt RMS amp will draw upwards of 50-60 amps at full output and prob slightly more during peaks. A 1000 watt amp is likely to draw twice that of course. How long do you think your factory 85 amp alternator is going to allow you to get away with more than 120 amps of current draw from a single electrical accessory in your car?

Stick with the 500 watter or less.

 

[crunktimes.com 5,000+ posts]

I am pushing 1100 watts on my stock (90 amp) alternator in my XB, just do the big 3 and upgrade your battery you should be all set for around 1000 watts.

 

[SSS 18734 5,000+ posts]

^ 400 - 600 watts should serve you well //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[WhoSayWho? 5,000+ posts]

About 1250rms here with an alty only rated for 70amp supposedly. Never had any problems. IDK.

 

[Flipx99 5,000+ posts]

Are you speaking about sub only or amps to power componets as well?

 

[memphisspl 10+ year member]

About 1250rms here with an alty only rated for 70amp supposedly. Never had any problems. IDK.

YET!

Never said it can't be done. It just isn't smart. Usually what happens is a smoked amp from massive voltage drop and/or premature failure of your stock alternator and/or battery.

 

[WhoSayWho? 5,000+ posts]

YET!
Never said it can't be done. It just isn't smart. Usually what happens is a smoked amp from massive voltage drop and/or premature failure of your stock alternator and/or battery.

Of course I mean YET! No dimming, no voltage drops.

So there.

 

[Atimm693 10+ year member]

Amps*volts=watts.

Just assuming with the 80 amp alty, and with some power you get:

648 watts total with 60% effieciency@13.5 volts

810 watts total with 75% effienceny@13.5 volts

Not counting how much power your car takes and whatever a batt(s) adds to that, also with the most uneffiecent amplifiers.

 

[Trunk_Monsta 10+ year member]

just my .02, i would upgrade my electrical anyway. u dont have to do it all at once, just get the "big 3" done first, then move to adding a stout battery in the back, next move should be a HO alt. b/c trust me, u will more than likely be upgrading your system after your ears get used to your current one. that way you will already have an electrical system b4 u upgrade. but thats just my opinion.

oh yea, u also have to worry about when your headlights are running, and all other accessories {electrically} are still drawing from your alternator and battery...

 

[memphisspl 10+ year member]

Good advice, except for one thing. Adding a new battery to the rear without isolating it from the front will trash your new battery if your front battery is old and beat up. Upgrade the front battery first, then install a supplemental battery in the rear of the same type and kind.