Charger Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
669 Posts
Discussion Starter · #1 ·
I have a U-pulley on my RT and I want to keep it. I also want to return my alternator to it's OEM rpms. Does anyone have a part# for a pulley I could put on my alternator that would do the job?
 

·
Registered
Joined
·
1,998 Posts
Are you having a problem with the alternator's output? Is it not charging properly?
 

·
Registered
Joined
·
669 Posts
Discussion Starter · #3 ·
Well, yeah... but my circumstances are not typical. I'm a Police Officer and I use my Charger as a patrol car. As a Police Officer, I have available the ability to work "side-jobs", what we call "special duty". These jobs are performed in uniform and consist mainly of traffic control at construction sites (some of which are on the freeway and do not require that you stand outside of your car and actually flag traffic) and sometimes security at events or gatherings of some sort.

A few weeks ago I was working a job on the freeway where I had to park my car at the rear of the constructioin crew who was working on a guardrail. The job lasted about eight hours. For about six of those hours I was sitting in my car watching DVDs with the engine and AC running. I know, I know... sitting at idle for that long is bad... blah, blah, blah. I'm paying for this car and I'm well aware of the pitfalls of long periods at idle. Regardless, this is where my problem started.

The car was fine until I turned it off when I went to ask the crew how much longer they were going to be (they were going longer than scheduled). When I returned to my car it was dead, would not start, not even turn over.

A friend of mine happened to drive by and saw me with my hood up. He offered a jump. It took a while but we got her going. I had to drive her home in "limp mode".

Shortly after that incident I went on a trip for about ten days and didn't get a chance to really drive the car and charge the battery fully after draining it. When I get back from the trip the car started but the radio would not turn on. The only thing I could get it to do was open and close the screen for disc removal. Everything else seemed to work fine.

I went to Sears to test my battery because I thought maybe I had damaged a cell. The battery tested fine and when I reinstalled it the stereo worked fine. I guess removing the battery caused the stereo to reset.

I know the slower alternator speed is the cause of this problem and I don't want to have this happen again. I want to keep my U-pulley so I'm guessing a smaller pulley on the alternator would keep her spinning at OEM rpms.
 

·
Registered
Joined
·
1,998 Posts
OK. That's a good bit of detail. Have you put a voltmeter on the battery to see what the idle voltage is? Do you have an EVIC display since it would also give you that info. If the voltage is below 13.8v at idle, what RPM will get the voltage back to at least 13.8v? You may be on the threshold of the minimum RPM's for the alternator to work properly and I wanted to find out if it needed 50 or 200 RPM's to get back to normal. If it is a small amount, you can get a Predator programmer and tweak the idle speed up to what you need it to be.
 

·
Registered
Joined
·
669 Posts
Discussion Starter · #5 ·
I have EVIC and a Predator. I did read the voltages earlier but I forgot what they were. When I was having issues I remember the voltage being at 11.4v. I'll mess with a little and try boosting the idle 500 rpms. I'll post my findings.
 

·
Registered
Joined
·
14,728 Posts
Not really.

The output of the alternator is controlled by the pcm, not the alternator. The stock alternators are capable of 17 volts and about 80 amps if the pcm allows for it. Now sitting at idle is extremely hard on the alternator. With the a/c on its under the most load it can be under at the lowest engine speed. the pcm will only allow for so much output at idle so as to not burn up the brushes and windings in the alternator. You could put a smaller pulley on but that will make no difference since the pcm will only allow x amount of voltage from the alternator anyway. In most cicumstances ( dont know bout the chargers) but their are higher output alternators put on police packages normally which is what i would check out if i was you.
I would also look into getting some heat shields for your cats. Cats can get to 600 degrees quite easily and the only way they cool is by air flow under the vehicle. Now the cop processors have a slightly different setting for idle so as to reduce fuel use which will help keep the cats cool which your car also doesnt have. Since you dont have the ability to put the cop processor in you need to look into heat shields prior to your floor boards melting (anyone with a crown vic police interceptor ) knows what i mean.
Sitting at idle is the hardest thing to do on the car. Youheat the tranny fluid, oil, and exhaust and without the proper programming you can really accelerate the life of a lot of the parts.
 

·
Registered
Joined
·
669 Posts
Discussion Starter · #7 ·
Not really.

The output of the alternator is controlled by the pcm, not the alternator. The stock alternators are capable of 17 volts and about 80 amps if the pcm allows for it. Now sitting at idle is extremely hard on the alternator. With the a/c on its under the most load it can be under at the lowest engine speed. the pcm will only allow for so much output at idle so as to not burn up the brushes and windings in the alternator. You could put a smaller pulley on but that will make no difference since the pcm will only allow x amount of voltage from the alternator anyway. In most cicumstances ( dont know bout the chargers) but their are higher output alternators put on police packages normally which is what i would check out if i was you.
I would also look into getting some heat shields for your cats. Cats can get to 600 degrees quite easily and the only way they cool is by air flow under the vehicle. Now the cop processors have a slightly different setting for idle so as to reduce fuel use which will help keep the cats cool which your car also doesnt have. Since you dont have the ability to put the cop processor in you need to look into heat shields prior to your floor boards melting (anyone with a crown vic police interceptor ) knows what i mean.
Sitting at idle is the hardest thing to do on the car. Youheat the tranny fluid, oil, and exhaust and without the proper programming you can really accelerate the life of a lot of the parts.
Thanks, bro. That is some good information. I guess an alternator upgrade should be on my "to-do" list.
 

·
Registered
Joined
·
1,998 Posts
I have EVIC and a Predator. I did read the voltages earlier but I forgot what they were. When I was having issues I remember the voltage being at 11.4v. I'll mess with a little and try boosting the idle 500 rpms. I'll post my findings.
You don't need to get that radical with the RPM change. Just feather the gas and ease up the RPM's until the voltage reading is good. That is where you can set the idle if it isn't way too high. I wouldn't go more than 100 RPM's over stock (stock is about 600).
 

·
Registered
Joined
·
1,998 Posts
I guess an alternator upgrade should be on my "to-do" list.
A different alternator won't do any better unless you can make sure it's minimum operating RPM is lower than the stock unit.
 

·
Registered
Joined
·
14,728 Posts
you could up your idle with the predator at the cost of some gas mileage. I mean you get 0 mpg at idle anyways but you'll still get a bit worse then that :grin:
 

·
Registered
Joined
·
14,728 Posts
i believe he said his isnt a police package
 

·
Registered
Joined
·
1,416 Posts
wicked-in your post #6,your own words were that if it were you,you would find out what the cop Chargers had for a alternator.I was kind enough to give him that info.
 
1 - 14 of 14 Posts
Top