Does anyone know where I can get a kit to ADD an alternator to my 302 in my 1988 F-150? If I added an alt that would make things turn slower (just like an underdrive pulley set) AND I would have more amps to work with for my stereo!! Hopefully a way to rig another alt onto the engine won't cost too much, but I know that decent alt doesn't have to cost much more than 100 bucks, so maybe this could be cheaper than an underdrive pulley set?!! Give me some feedback on this idea!!

 

Even if it did make it turn slower the drag from the extra alternator would decrease horsepower. There are companies that sell kits to add an extra alternator and a transformer so you can weld if you brake your truck offroading in the middle of no where. I have one on my x-mas list!

-Jon

 

Okay, I'll bite. How is it that you figure adding an alternator would have the same effect as installing an underdrive pulley kit?

Take care,
-Chris

 

As FORD302GUY explained to me "Underdrive pullies turn the accessories a little slower thus giving you a little more power" So I thought, well an alternator's pulley could do the same thing as just a plain underdrive pulley. I know that the alternator will give the belt more resistance than just a plain pulley spinning on it's own, but that is why I asked you guys for your feedback, do you guys think that this is a stupid idea? I know that it won't be AS much of a performance gain as an underdive pulley, but will there be ANY performance gain? This is just an idea I've been tossing around, and I don't have enough hours spent on an engine to be able to figure this one out by myself.

 

Flawed logic... hehe

Underdrive pulleys use a smaller cranks pulley and they slow down the accessories because they spin slower. Your idea is to slow them down by adding drag which would cost HP. The speed of the crank is set, but the "gear ratio" if you will is making it easier to turn the other stuff.

It would be similar to saying that going up a steep hill would help HP because the accessories are turning slower....


In your case swapping to a different alternator that puts out more amperage at low speeds might let you get away with a pulley set. With the stocker you might have problems with high end audio gear. Another option is looking into dual batteries, but you are adding weight and eating up some of the HP you gain with the pulleys.

 

I'm having trouble following you, but I think I see what you're saying. Are you under the impression that an underdrive pulley is an additional pulley that you install? If that's what you're thinking, then I understand your alternator idea. The problem is that underdrive pulleys are replacement pulleys for ones you already have. The set comes with a smaller than stock crank pulley, and larger than stock water pump and alternator pulleys. This combination requires less energy from the engine to turn the accessories, but in turn, the accessories will be spinning slower, which could compromise their functions.

If I missed your point completely, please explain it in more depth. I'm curious.

Take care,
-Chris

 

I see said the blind man, no one explained REPLACING existing pulleys, thanks for clearing things up, I guess it's back to the drawing board. I have been thinking about adding another battery with an isolator to my system like signmaster said, I do have a 95 amp alt, so I think that it could handle it...I'll stop rambling, anyways thanks guys for clearing things up

 

I have two batteries in my truck, and it's great! I have all of my added accessories wired to the "backup" battery, and the isolator makes sure it stays charged, but won't let it become drained if there is a problem with the primary battery. Let me give you a real example.

A few weeks after I installed the backup battery and isolator, I drove me and my buddy to the hi-po parts swap meet in Long Beach, about 90 minutes away from here. We went early, and it was foggy, so I had my headlights on. Well, I forgot to turn them off when we got there, and we were there for 6 or 7 hours. When we got back to the truck, the battery wouldn't even light up the dome lamp.

Solution? I grabbed my jumper cables and "jumped myself". Worked great.

Take care,
-Chris

 

yes as chris stated . he jumped himself . but as the set up i had on my 67 F250 . lets take that a notch further . i added an "Auxillary start switch" a simple momentary switch wired to a battery solenoid to connect the two batteries together when depressed . no need for jumper cables . no need to get out of the truck to do it . it takes a bit more work to set up but well worth the extra time, money and battery cables, this is a nice add on , especially in the rain

 

That's a very good idea. I can't use rain as an excuse until November, but I'll figure something out.



Take care,
-Chris

 

My next upgrade will be pulleys, but does anyone know where I can get a 100 or 120 amp alternator that will bolt right up to my 5.0L?

Or, what about a smaller pulley for my stock alt? Does Ford Motorsports Performance catalog have stuff like this? Does FoMoPerf have alot of truck applicable stuff?

 

Inski,

The FRPP three piece set comes with a smaller alternator pulley. Charge is still less than the stocker at idle, but I haven't had any problem so far.

They have them on the web site but not sure if they show a cross reference to the trucks. My local Ford Racing distributor had the notes in his book. I got the three piece blue powder coated for $99.