Using Amps while using UDP

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rigol2000

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I am about to buy a complete sound system for my 95 that did not have the premium system. I currently have a very old Sony head unit going to factory speakers with no sub. I will be installing a head unit, new speakers, a subwoofer and two amps. The sub amp will be around 300 watts and the other around 200 watts. My question is more an electrical question. I am running a stock alternator and under drive pulleys. I already notice my headlights dim at idle. With the alternator turning at lower RPMs from the UDPs, will it be able to produce enough juice to power this sound system? Anyone with a similar set up?

Thanks,
Chris
 

hawkeye18

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Yeah, I have nearly the same setup, 350WRMS to the subwoofer and 68WRMS total to the corners thru the HU. The lights do dim appreciably, and at night at idle the battery struggles to maintain 12V. And yes, I have UDPs also.

If you tip in the throttle just a wee bit to 800rpm, it charges fine, though. I have an LPM that I plan on reflashing just as soon as SOMEBODY STARTS PROGRAMMING THEM! *cough* lol j/k axianator, I wouldn't throw you under the bus like th... oh wait, whoops. never mind.

You'll be fine.
 

rigol2000

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I've seen a special service 150a alternators at CincySHO. I wonder if these would put out more amps than stock at these lower RPMs?
 

jedhead

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I have 400w rms Alpine V12 amp and have UDP's. My lights don't dim and I don't have any problems. However I have my idle set at 1100rpm with a LPM.

Bob
 

93rev2sev

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Ya use the stock alt pully. When you wanna race or whatever, turn off the radio, EATC, Fogs, Etc..

You would do that anyway I would think.
 

crazy_canadian

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I've seen a special service 150a alternators at CincySHO. I wonder if these would put out more amps than stock at these lower RPMs?

I heard that higher output alt. Will produce less power in low rpm range, but will have a higher peak output. So, it won't solve the problem.
 

SHOZ123

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Some things I wonder about with people wanting to use the high amp output alternators is first do you really need that much current? Have you actually measured the current draw?

I wonder too if the output bolt is a larger size as sending 150-200 amps though a 6mm post will generate a lot of heat.

Of course upgrading all the primary charging system wires is the first thing to do.

After that, if the voltage is still sagging at idle your needs are best served by a voltage regulator and larger battery. Kind of expensive but you got to do what you got to do.....
 

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