2003 Mitsubishi Lancer, Alternator amps?

I just bought a 2003 Mitsubishi Lancer OZ Rally Edition, and I am planning on putting a new stereo in it. First question I have is, what is the stock alternator amperage rating on this car? I plan on putting in a 600-800w RMS sub in the trunk, so I'm gonna need quite a bit of power. Secondly, I may or may not replace the stock speakers, depending on what my budget will be in the next few weeks; the stock ones sound pretty good to me, but I'd like to know how many watts RMS they're putting out. That way I can know if my Kenwood XXV-01D HU (gives out 22wx4 RMS) is powerful enough for them. Unfortunately it'll be hard to check since the speaker grilles don't seem to come out very easily...? If I do get new speakers, however, I'm thinkin' about gettin' some ones that put out about 50W RMS each, so I'm gonna need a 200Wx4 RMS amp as well. (You can see now, why knowing the stock alternator's amp rating is so important.) I've searched around here and well as Google, and I really couldn't find much info on this car (except for a HU wiring diagram ). Any help is greatly Appreciated. Thanks, - ScY

psythik wrote: If I do get new speakers, however, I'm thinkin' about gettin' some ones that put out about 50W RMS each, so I'm gonna need a 200Wx4 RMS amp as well.

Oops, I meant to say "50Wx4 RMS amp".

Thanks for that info; it helps a lot. Ok, so I found out that the stock speakers are only 15w each(!), which is suprising since the bass response from them seems much better than from the Blaupunkt 75w 16x9s in my old '86 4Runner. However, the highs are lacking and the sound distorts at higher volumes, so I am going to eventually replace them. They all seem to be the same shape (looks like either 6-1/2" or 6-3/4"), so that's good since it'll be easier to shop for speakers. So with a 90amp alternator, I probably have about 36amps of reserve capacity to work with (90amps / 40%) . Therefore, a 500w sub amp would utilize about 24.2amps (500w * 2 [for amp inefficiency] / 13.8 [alternator voltage] / 3 [since generally only a third of an amp's power is probably used on average] = 24.2amps), leaving me with about 11.8amps to work with. Now a 200w 4-channel amp would utilize about 9.6amps on average (using the same formula), which means that with a 500w sub and four 50w speakers, I will be using about 33.8amps on average, just 2.2amps below my reserve limit. Of course, what I've calculated is the average draw (not maximum), so getting that close to my alternator's reserve limit is pushing it a bit. Of course, I could just get a power cap (and maybe step down to a 450w sub amp), and I should be okay, correct?

Read the sticky about "the big 3".  A power cap is not the answer.  The idea of a power cap is to help maintain a constant voltage to your equipment, which can help extend it's life.  However, this will only work if the alternator is up to the task of maintaining a healthy voltage.  Also, just because your alternator is rated at 90 amps does not mean that's what it actually produces anymore- your local parts store should be able to test it on the car at no charge.  If you think your alternator is borderline, then it probably is.  My advice is to do the big 3 and install your equipment.  If you have any noticable voltage problems, upgrade the alternator as well.  My ex once told me I have a perfect face for radio.

Replace the speakers. Stock speakers suck and the bass response is good because thats what the speakers are tuned to do. Aftermarket speakers generally dont get quite as good a bass response as factory speakers because factory speakers are designed with a much higher sensitivity in mind. They have to make alot of noise with a relatively small power supply. But as you seem to already know, most of the frequencies are going to sound muddy at high volumes.

I agree with the above, but I'm hopping in here to make one point: the wattage rating of a speaker has NOTHING to do with how it will sound or how much bass (or anything else) it puts out.  Wattage ratings are simply that: how much power it will handle.  NEVER shop for speakers based on their wattage ratings, shop for how they sound.Support the12volt.com