underdrives and charging problems?

[84blkstang]

I am looking into buying underdrive pullies. This weekend I asked my uncle and he said that I would have a charging problem with my stereo, i have two 12's wired at 4 ohms and a memphis 500 watt amp, not a class D. What size of alternator would i have to get to run this stereo and all of my other accessories lights, fan motor, radio ect? Could I get underdrives and not use the alternator pulley what belt size would I need then? I am open for any suggestions.... just throw your opinion in thanks

 

[Black 93 Fox]

I forget the size alt everyone is going to. Yes you can run the under drive pulleys with out the alt pulley. As for the belt have to do some try and error. When I did pulleys I tried one didnt work tried another and it worked.

Black 93 Fox

 

[5.0CRAZY]

Its usually 130amp alts that people upgrade too, you can get them off 94-95 mustangs or buy new from aftermarket companies.

You can skip the alt pulley, but if you do it makes it more likely that youll have to get new belt. I skipped the alternator pulley and needed a new one, with a stereo system I wouldnt suggest installing the alt pulley. I would bet the power gain from the alternator pulley would be close to nothing anyways.

 

[willys1]

I didnt do any of them.If its not good for your charging system,how good is it gonna be for the other two? Is it worth the 6 HP??

 

[1hot5.0]

The size belt you need is an 89.5. I would upgrade to a 130 amp alternator with a 1 7/8 alternator overdrive pulley.There is an auction going on ebay right now for a 130 amp 3g alt. for $55 so far.

 

[Michael Yount]

As mentioned above, the 130A and 140A (aftermarket) alternators are the common upgrade. They came standard on the SN95 cars. THe stock 65A alternator is barely adequate for the fox bodies. With your increased electrical load, you're asking for problems on the charging side if you go with underdrives and don't upgrade the charging system. Depending on where you live, how you drive - be sure the cooling system components are up to snuff too. There are simply too many variables for any reliable prediction about what's gonna happen when you put them on - you'll have to try and see. After trying to make them work on mine, I eventually put the stock pulleys back on to solve charging and summertime low speed cooling issues.

 

[84blkstang]

I dont think I will put the underdrives on. I enjoy my radio too much and I dont want to have charging problems. I my car has a brand new water pump, and a brand new stock radiator with a 180 degree thermostat and I dont use my ac so I dont think it will have a cooling problem. I dont really think that for the money the pullies are worth the headache down the road. what else could i do for around 150 that i dont have already? i am open to any suggestions