Alternator Really not an HO?

[helotaxi 5,000+ posts]

Alts have both a rated max output and a rated RPM at which they'll deliver that output.

I'm gonna bet that the 200rpm or so difference between the car in Park and the car in Drive is enough to drop the output of the alt below what you are drawing. Running an undersized alt pulley will make a big difference there.

 

[Qbenjamin 10+ year member]

I changed the belt, as per their suggestion, which was a ***** to get that new belt on since it was so tight. I am about to go and get my batteries tested, and I will let you know how it goes.

 

[helotaxi 5,000+ posts]

The belt and the pulley are two different things and serve two different purposes. The shorter belt was to prevent slipping, the smaller pulley is to spin the alt faster. Since output is limited by low RPM, upping the RPM at idle might fix all your problems. The fact that you voltage drops when the RPM drops slightly and that it comes right back and is solid with higher engine RPM,indicates that this should fix the problem.

 

[IgnoreMe 5,000+ posts]

I changed the belt, as per their suggestion, which was a ***** to get that new belt on since it was so tight. I am about to go and get my batteries tested, and I will let you know how it goes.

too tight of a belt can damage your motor...just to let you know. you want it tight so nothing slips but not so tight as to be pulling the crankshaft up and making it wear differently against the mains...

does your engine have a self tensioning tensioner?

 

[cunokyle 10+ year member]

As helotaxi stated, most alternators have rated power output for idle and when the rpms increase. Adding a smaller pulley to the alt should take care of the problem for you.

 

[Qbenjamin 10+ year member]

For you all that keep saying the stuff about the belt not doing anything, I was just following the troubleshooting of the Tech @ DBELECTRICAL. I just got back from getting my batteries tested, and everything is fine with them. The voltage drops from 14.2v @ idle with no music, to 12.3 with music. If I put the car in drive, the voltage drops from 13.9v to 11.9-10.9v when the bass hits. I am furious with this whole situation now. I am only running my amp @ 2 ohms (800w) and I am experiencing voltage dops this bad? WTF? Back to the stock alt I go.

 

[Grinder1989 5,000+ posts]

Well if your having that many problems, return it and buy another one from a different company? Summit Racing has some good high amp alts.

 

[Qbenjamin 10+ year member]

I think I am going to give excessive amperage a try.

 

[SPL140.2 5,000+ posts]

I think I am going to give excessive amperage a try.

dominick@tds.net //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[cunokyle 10+ year member]

For you all that keep saying the stuff about the belt not doing anything, I was just following the troubleshooting of the Tech @ DBELECTRICAL. I just got back from getting my batteries tested, and everything is fine with them. The voltage drops from 14.2v @ idle with no music, to 12.3 with music. If I put the car in drive, the voltage drops from 13.9v to 11.9-10.9v when the bass hits. I am furious with this whole situation now. I am only running my amp @ 2 ohms (800w) and I am experiencing voltage dops this bad? WTF? Back to the stock alt I go.

Sounds like a reasonable drop when at idle and at idle in gear. The alt is probably putting out 105 or so amps at idle. Hence the reason at most dBDrag comps they let you rev to 2000rpm.

 

[Qbenjamin 10+ year member]

Sounds like a reasonable drop when at idle and at idle in gear. The alt is probably putting out 105 or so amps at idle. Hence the reason at most dBDrag comps they let you rev to 2000rpm.

I don't want to have to rev my engine everytime I get to a light, that would be extremely annoying. My battery light is constantly popping on. I am just going to send it back and look for one from someone else.

 

[QtrHorse 10+ year member]

You might want to try these guys as well, Alternator Parts.com. They are a little more pricey than DB but build a better alternator in my opinion. DB just rewinds there alternators in most cases and Alternator Parts.com uses larger housings on most of there alternators which keeps the alterantor running cooler.

 

[cunokyle 10+ year member]

I don't want to have to rev my engine everytime I get to a light, that would be extremely annoying. My battery light is constantly popping on. I am just going to send it back and look for one from someone else.

Whoever you decide to look at, be sure to call and tell them exactly what you are looking for. Would hate for you to get an another alternator to only have the same thing happen. I know that every alt I looked into had an idle output and a load output.

 

[Qbenjamin 10+ year member]

Whoever you decide to look at, be sure to call and tell them exactly what you are looking for. Would hate for you to get an another alternator to only have the same thing happen. I know that every alt I looked into had an idle output and a load output.

I didn't do enough research at first, that was my first mistake. I still don't know if I even need a 200amp alt. I am only running 1500w, and I will not be running anymore than that. You know the weird part is that I am only running my amp @ 2ohms, and the alts that I got from DBELECTRICAL can't handle that? I was running my Orion 2400D off of my stock alt with no problems, but this was before I did the big 3 upgrade. Could the 1/0 wire be accepting too much current? I am hoping that this isn't an error on my part.

 

[QtrHorse 10+ year member]

No, the 0ga wire should not have made it worse. Are you sure the connections and grounds are good?