Skyset

Hey,

I just picked up this subwoofer for my IROC http://www.futureshop.ca/en-CA/produ...68b9709f3aen02

however, being a car noob, my friend told me that my stock alternator wouldn't be strong enough for those subs? Will I have to upgrade my alternator? Or would it depend on the amp i get?

Thank you

munk20

iTrader: (1)

i think you should be alright with the stock alt, if you have power concerns after you install your system, you could always run a second battery and put it in the rear glovebox

8t2 z-chev

'86 TPI IROC is (IIRC)108 amp 17si-plenty for a quite
large audio systemI have 85 amp 15si in my '82 and
very easily handles my ~400w"old skool"system.

Six_Shooter

iTrader: (2)

Stop listening to your friends...

The subs themselves have no bearing on what load will be placed on the alternator. Items like amplifiers, and other electrical dives that are directly powered by the vehicle's electrical system do.

I find that in most cases as long as the stock alternator is working properly it is enough for most people. Doing the "big 3 upgrade" (Adding heavier gauge wiring to certain areas) will help more than just swapping a larger alternator in place.

abray1

There is a bracket kit you can get and use a CS144 alternator. That is what I did and I have plenty of juice now. It puts out over 200 watts and you might want to look into using #4 fine stranded wire from your alt and major power highways. I put my battery in the trunk and used #2ought to a power block on the pass fender and my starter spins noticeably faster and my lights are brighter.

johnf123

i got a 1600 watt amp and a 450 watt amp, no capacitor, using a stock 1992 alternator which is probably bad anyways. I have a BBK underdrive pulley kit which includes a huge alternator pulley. i have some problems, but if you let it idle for awhile rev it up a lil before u kill it, and turn all accesories off before doing so.

Tibo

iTrader: (15)

Agreed. Running larger gauge wire with an increased wire count will help quite a bit. So many people buy larger alternators but stick with the stock alternator output wire (10ga?). A good 8ga helps, 4 gauge might be overkill though. Grab yourself a capacitor or a second battery if you will often drive with the subs at higher power levels.

BluFBdy

iTrader: (1)

Technically this is a half truth, the subs do effect the alternator down stream, by loadingthe amp with whatever ohm load is chosen it will use more or less juice to the amp from the alternator.

That being said dead on with the big 3. I have 2 amps running my subs and interiors and at a light sitting still my lights would dim car would die out etc. After upgrading the alternator to 4 gauge and the grounds to 0 I have no problems. No dimming or anything

Like six said, stop listening to your friends. Most people who think they know what's what have a package deal sub and amp setup that was installed for them so they automatically know how to set up a system right? No.

Additionally don't run a capacitor. They're useless these days and just draw on your alternator shortening the life span. New age amps star much less power than they used to so running a capacitor on the system is a joke. If anything install a secondary battery like a stinger or something.

Your stock alternator will do just fine. If you're worried then upgrade your wires and call it a day, no need to reinvent the wheel if you don't have to

Six_Shooter

iTrader: (2)

I disagree completely about which subs will have any effect on the load the electrical system has.

ANY sub (or subs) can place a load on the amp, at any impedance that you apply to the amp, based on the speakers impedance, how many are connected, and how they are connected. So to say a particular speaker or set of speakers will place a higher load on the electrical system than another, is factually incorrect. The amplifier has a direct affect, yes, but the subs have zero bearing on what kind of a load will be placed on the electrical system. So, no, it's not even a half truth.

I also disagree about a stiffening capacitor, when used for it's intended purpose, and not the band aid they have been sold as for years. I posted elsewhere, how and why they are used for their intended purpose, but will not get into it in this thread.

BluFBdy

iTrader: (1)

Run a 500 watt amp at 4 ohms at 250 watts or take it down to 2 ohms and run the full 500, regardless of svc, dvc, 1,2,3 or 20 subs, the lower the load the more current that will flow, absolute basics of electricity. Meanning a higher power output which means a harder load on the alternator. That's exactly what happens until you step into pdx and rips technology. And regardless of intention without a true by the book use they are band aids and useless. When people pony up for high end equipment the need for a capacitor is virtually eliminated until you step into high power applications where more than 2 amplifiers are being used and at that point a gel cell battery is more effective than a capacitor. They are old and pointless now. They used to be necessary when an amplifier was the size of a skateboard and had massive heatsinks with fans but that's not todays reality. There is no buffer needed because amplifiers are becoming more efficient due to the smaller and smaller gap between what a new car needs to operate all the factory equipment and what the alternator full fields at.

Useful for a salesmans average ticket and getting money out of a customers pocket into the installers, thas it.

BluFBdy

iTrader: (1)

Run a 500 watt amp at 4 ohms at 250 watts or take it down to 2 ohms and run the full 500, regardless of svc, dvc, 1,2,3 or 20 subs, the lower the load the more current that will flow, absolute basics of electricity. Meanning a higher power output which means a harder load on the alternator. That's exactly what happens until you step into pdx and rips technology. And regardless of intention without a true by the book use they are band aids and useless. When people pony up for high end equipment the need for a capacitor is virtually eliminated until you step into high power applications where more than 2 amplifiers are being used and at that point a gel cell battery is more effective than a capacitor. They are old and pointless now. They used to be necessary when an amplifier was the size of a skateboard and had massive heatsinks with fans but that's not todays reality. There is no buffer needed because amplifiers are becoming more efficient due to the smaller and smaller gap between what a new car needs to operate all the factory equipment and what the alternator full fields at.

Useful for a salesmans average ticket and getting money out of a customers pocket into the installers, thas it.

Six_Shooter

iTrader: (2)

I agree about the power draw of the amplifier, but which subs cause that impedance do not matter, which is what it sounds like his friends were trying to imply, so again sub choice has zero to do with electrical system load on a vehicle.

You've been brainwashed into thinking that stiffening caps are used as batteries. They defintely still serve a purpose. I'm not saying that every system absolutely has to have one, but many systems cam benefit from them. They were never intended to hold voltage up for long periods of time, like they were sold for, that would be what a battery is for. There is quite a lag between when an amplifier, even efficient ones, starts to draw power and when the alternator actually increases output to match demand. This lag can be a few milliseconds, in a well planned out voltage supply sytem, the cap will help fill in for those few seconds. The other great benefit is that the cap will also filter out any remaining AC ripple that hasn't been filtered by the alternator and battery already. An alternator's output is actually quite noisy, though they have been proved over the last decade.