I will go ahead and get the question out of the way before I explain my situation. I would like to know how to find out whether my pulley is stock or not and if it a underdrive pulley?Ever since I got my car last february I keep finding that I have stuff done to it that I didn't know about. With the past few monthes I have had problems with keeping my voltage between 13- 14.5 @idle. When I am driving it's fine(runs about 13). So far I have installed a powermaster 200 amp alternator, red top optima, both battery terminals converted to top mount and all my wires converted to 4 gauge oxygen free wire. Still the problem persist so I was installing new headers and exhaust a couple of weeks ago and I took a look at the crank pulley while I was under the car and I took a look online and I don't believe it is stock and I would like to know a way to find out. I read before that a underdrive pulley can cause voltage issues, if so how can I fix this and do they make an aftermarket that would stop the voltage but not take away the horsepower? Thanks for any info ahead of time.

 

Do you have pictures of it? I believe they sell u/d pulleys now that dont rob voltage. Check around on Summitracing.com.

 

I've never had problems with underdrive pulleys robbing voltage. You definitely shouldn't be having problems with that big alternator you're running. You have a big sound system? How bout your grounds, they all snug and non-corroded?

 

I haven't installed the system because I have been trying to fix the electrical issue first. I am getting a capacitor though so voltage won't become an issue and I would never put neons on my car. It's like asking for tickets. I'll just contact summit by phone and have them help me out. Thanks.

 

what exactly is a capacitors job?

 

Capacitors to what I understand start to gather and store power so when the subwoofers hit they don't pull their power from the battery but from the capacitor. Capacitors are rated by farads andone farad is needed for every 1000 watts a sound system produces. This is what I have read and have heard through word of mouth. I am installing my sound system my self and I will post pictures when its all done in my gallery.

 

ok kuz i installed my own system too and it pulls on my alt hard and i JUST got a new replacement AC Delco. Some times at stop lights it will be so bad my dash/headlightslook like strobes.. but when i drive its fine.

 

SSPOWER is correct in saying the usage for a capacitor in a car audio use. It's a slow discharge capacitor, so it in essence acts like a temporary battery. If the battery cannot provide ample power to power the system, it can draw current from the capacitor. The more capacitance the capacitor has (aka, the higher amount of "Farads") the more charge it can store, and thus the longer it can power something without being recharged by the car battery. They also make fast discharge capacitors that store energy up to a certain threshold and then discharge quickly, but those are used in camera flashes etc. stuff that you need a lot of current fast, but you don't need it continuously.

 

are you getting your voltage reading off the gauge or from the battery? maybe its just the gauge. besides a low reading, are your headlights dim?

 

well my guage usually dances around and the dash and lights will dim but on some occasions it will be so bad that it looks like strobe lights no joke.