Steeda Under Pulley | Charging

[JerZeyStangz]

I think I have two issues going on that are working in conjunction with each other. I recently threw on a old school set of brand new steeda UDP's. The good - I gained a significant amount in gas mileage and a slight bump in performance. The bad - the UDP's are not charging my battery at idle when all the accessories are being used such as radio, head lights, a/c unit.

Now during the day it is not as much as issue, but at night it rears its ugly head. My car almost died in severe traffic this evening. They were doing construction on my route to my house and the car was barely charging at idle. It got so bad that I had to throw it in neutral and manipulate the RPMS so that it won't die. My Dash lights went out, and my ABS light turned on and my battery light as well.

My question is should I go back to a stock alternator pulley or should I replace my battery? Or maybe do both? I know I have semi weak battery to begin with but I don't want to replace it in a future just because the alternator pulley isn't charging at 13.4v+ at idle. Thoughts?


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[mcglsr2]

Easiest thing to do right now I would think is to have your battery tested. Take it to Auto Zone or whatever and have them test it - they'll tell you if it not holding a charge as good as it should, etc. If they say it's going out, then get a new battery, and see if your troubles continue. Just understand that at idle you are using more of your battery and less of your alt.

If they say your battery is good, then you will probably need to change out pulleys. I imagine your battery is going bad, as I would think there would have been a slew of internet rants about the UP's causing problems (and maybe there were, I didn't actually check <shrug>).

 

[the5.ohh]

I agree with said above. However I vote take off the ud pulleys either way. They put more strain on the accessories and end up causing issues. I refuse to use them on either mustang. Just my .02 though.

 

[JerZeyStangz]

Easiest thing to do right now I would think is to have your battery tested. Take it to Auto Zone or whatever and have them test it - they'll tell you if it not holding a charge as good as it should, etc. If they say it's going out, then get a new battery, and see if your troubles continue. Just understand that at idle you are using more of your battery and less of your alt.

If they say your battery is good, then you will probably need to change out pulleys. I imagine your battery is going bad, as I would think there would have been a slew of internet rants about the UP's causing problems (and maybe there were, I didn't actually check <shrug>).

My battery is about 5-6 years old has been trickle charged for a good portion of its life in the garage. It is getting up there where it probably needs to be replaced, but thanks for nice plan of action. I will do that.

I agree with said above. However I vote take off the ud pulleys either way. They put more strain on the accessories and end up causing issues. I refuse to use them on either mustang. Just my .02 though.

Steeda's are the only pulley's that I will put on mustang. They are not piggy-backed and have harmonic balancer built into them. They developed them with Ford and can only make this claim. I think the alternator pulley is good for maybe 1-2rwhp so it is not a big deal. One of the biggest surprises I had with these pulleys is that my MPG's shot up like crazy. I know on the pushrod engines a lot of people had big issues but on the modular platforms its rare. I will get the battery tested and take it from there. Thanks Joe.

 

[lwarrior1016]

I had pullies on my car and noticed my alternator would charge low. When you did your swap did you install the alternator pulley from the kit, and was it much difference in size?

 

[JerZeyStangz]

I had pullies on my car and noticed my alternator would charge low. When you did your swap did you install the alternator pulley from the kit, and was it much difference in size?

IIRC, the pulley diameter looked smaller at a quick glance to the stock alternator pulley. When I get home tonight I will compare sizes take a picture for analysis purpose for you guys. One thing I noticed was in the morning when the car is stone cold, the battery on stock gauge sweep stays between 13.4-14.1. After the car is fully warmed up it dips closer to 8v side of the guage. It looks like its charging at 11-12v which doesn't look sufficient at all.

 

[lwarrior1016]

12v charge is not sufficient. I would try the stock alternator pulley first and see what it does. You may end up putting the stock pullies back on.

 

[JerZeyStangz]

12v charge is not sufficient. I would try the stock alternator pulley first and see what it does. You may end up putting the stock pullies back on.

Awh man! I will take some measures and if it comes to that I will put the stockers on if I can't remedy the situation. I really like the low end grunt and mpg's from these things. Sigh...

Load test Battery -> Battery is Bad -> New Battery.

Load test Battery -> Battery is good -> Keep Battery.

Replace UD alternator pulley -> Stocker.

If charging system still suffers -> Old pulley's going back on.



Nate

 

[ttocs]

UDPs are great on track cars. You will not see a difference at high rpms in the voltage but as you have seen at idle and at night your causing problems. The real issue is that while you have now choked the output of the alt, you have not reduced the current demands on the system. The means the alt will be getting hot and even worse yet it is designed to cool itself while is spins so when that is slowed, so is its cooling ability. I personally melted down one alt before the old timer I took it too to repair it told me this and it makes sense. If you do a lot of city driving vs racing you need to reconsider UDPs unless you like replacing your alt.

 

[JerZeyStangz]

UDPs are great on track cars. You will not see a difference at high rpms in the voltage but as you have seen at idle and at night your causing problems. The real issue is that while you have now choked the output of the alt, you have not reduced the current demands on the system. The means the alt will be getting hot and even worse yet it is designed to cool itself while is spins so when that is slowed, so is its cooling ability. I personally melted down one alt before the old timer I took it too to repair it told me this and it makes sense. If you do a lot of city driving vs racing you need to reconsider UDPs unless you like replacing your alt.

Update: Before I headed to work I went back to shop and they popped my stock pulley back on. Here's what I noticed...the alternator is now charging at 13.4v-14.1v at idle when parked. When the car is under load such as foot on brake, radio on etc...it doesn't drain as bad when the steeda UD alternator pulley was on. They also tested my battery and its not putting out the proper amps as it should so that is another big factor. The battery can hold a surface charge just fine but when you need the juice at night it just doesn't suffice. I will eventually replace the battery with a stronger unit. Does anyone recommend any brands?

Thoughts: There are two solutions to rectify this situation so you can get the best of both worlds. I believe raising the idle speed 100-150rpms will resolve the slow charge at idle. Another solution is probably buying a stronger alternator.

 

[lwarrior1016]

I dont know how people here feel but I really like Red Top Optima batteries. They last a long time and hold a great charge, and they are plenty strong. My red top hasnt been charged since before December last year when I bought it and it still turns over my 12:1 compression 2v just fine. They are also gel filled so it can be put inside the car without a vent. Finally, if they die, they can be charged back from dead with either an optima charger or a neat little trick using a regular charger and a second battery with some jumper cables.

 

[JerZeyStangz]

I dont know how people here feel but I really like Red Top Optima batteries. They last a long time and hold a great charge, and they are plenty strong. My red top hasnt been charged since before December last year when I bought it and it still turns over my 12:1 compression 2v just fine. They are also gel filled so it can be put inside the car without a vent. Finally, if they die, they can be charged back from dead with either an optima charger or a neat little trick using a regular charger and a second battery with some jumper cables.

Definitely want to look into that, how much do they usually run?

 

[lwarrior1016]

I think they are around $280? Im not real sure what I paid for mine. You can get them cheaper in some places.

 

[JerZeyStangz]

I think they are around $280? Im not real sure what I paid for mine. You can get them cheaper in some places.

American Muscle has them going for 185.00 shipped, so that is not bad at all. Might as well put something stronger in. Did you have a problem putting this oversized battery in the stock battery tray. It seems like a lot of complaints about it being a tad too big?

 

[lwarrior1016]

American Muscle has them going for 185.00 shipped, so that is not bad at all. Might as well put something stronger in. Did you have a problem putting this oversized battery in the stock battery tray. It seems like a lot of complaints about it being a tad too big?

Oversize? Mine fit perfectly. Ill see if I can dig up an old picture. I know there are 2 different sized red tops but mine fit great.

Edit: I dont have any old pictures. Mine is now in the trunk so it really doesnt matter what size it is.

 

[JerZeyStangz]

Oversize? Mine fit perfectly. Ill see if I can dig up an old picture. I know there are 2 different sized red tops but mine fit great.

Edit: I dont have any old pictures. Mine is now in the trunk so it really doesnt matter what size it is.

Yeah it seems like AM sells a universal red top so if you can find the part number or a picture that would be great.

 

[Mustanger]

I get 7-8 years from Ford Autolite premium batteries @$119...

 

[lwarrior1016]

Yeah it seems like AM sells a universal red top so if you can find the part number or a picture that would be great.

Yeah the red tops are universal and when you buy them, they come with different trays and mounting brackets. I'll see if I can get a picture of when mine was in the engine bay.

 

[JerZeyStangz]

I get 7-8 years from Ford Autolite premium batteries @$119...

Yeah the red tops are universal and when you buy them, they come with different trays and mounting brackets. I'll see if I can get a picture of when mine was in the engine bay.

I was doing a little research and I found out the stock alternator puts out 110amps, and at idle with underdrive pulleys put out around 75 amps which is insufficient. Stock pulleys with stock charging system puts out about 85 amps which is sufficient. In order to run this mod with no sacrifice in power at idle you can upgrade the alternator and battery.

I am going to upgrade to a stronger battery and see what my results are...I am the type of guy that likes my "cake and eat it too" type solutions. One thing I can conclude is that underdrive pulleys definitely exploit the weaknesses in my charging system. If I didn't have a weak battery to begin I don't think I would be finding solutions. I would just say screw it and live with the slightly dim lights at night but I can't stand that.

130a alternator + 1000 cranking amp Battery = success.

Right now my setup is: 110a stock alternator + 800 cranking amp Battery = insufficient for charging at idle great for regular driving.

Last resort solution is bumping the idle up 100rpms because I notice it charges a lot better at the blip of the throttle. I know this is a big investment into the charging system for our cars but upgrades are always better since our cars are almost 20-25 years old now.

 

[ttocs]

the new battery will help for a while, but since the piece you need to recharge it isn't working 100% its going to slowly drag the battery down when it can't recharge. Putting an upgraded alt to make up for slower speeds is also just a band aid on the wound as again its not going to cool itself just like the stocker, and besides that an upgraded alt creates a bigger load on the motor then a stock alt so your borrowing from peter to pay paul in this scenario. Again UDP's are great on track cars but on a daily you will figure out pretty quick if its not a good idea for you when the battery/alt fail.