FiveOhNo

I recently bought a 91' GT and was asking a mechanic about installing an electric fan on it. he replied by saying the clutch fan was actually better and that if i still wanted to do the conversion i would need to buy a bigger alternator. is that true, or can the stock alternator handle it? i had a 280zx turbo before thiscar and did the conversion along with an ignition amplifier and coil on the stock alternator and itworked fine...???

vfast

depense on how big the one is you need something in the 2000cfm's I would put a 140-160 amp in it with an underdrive pulley..this will about double the life of the alt and pick up a few ponies and still be big enough to run the fan and a nice size amp.it's a win/win thing<edited><editID>vfast</editID><editDate>37945.7302430556</editDate></edited>

95cobragirl

in my opininon electric fans are definitely better....from my knowledge they tend to keep the 5.0 cooler than the old school clutch fan, jenna

69Stang

Well, I defenetely aggree that electric fans are a great idea for cooling engines, i know ive had about 5 total 5.0 engines, trucks, thunderbirds, cougars, 5.0 mustangs, and they always have cooling problems someway some how, but what my friends did was get a underdrive pulley so you would get more amps on your alternator and with the water pumps will flow better, with more amps get a small honda fan or toyota and wire it up with a current reflector so that you can adjust the speed or power intake of the fan, this should kool the radiator a lot, me and my friend did it and his car has no problems at all, he has gained a lot more miles / per gallon on high way use and it was a 6 hours project , well 7 hours, we did go to eat at jack in the box, but anyways, yeah its a good project to do with friends drinking beer and just having a good time, with a sour dough jack and a beer, and a good working mustang, we went of to the strip clubs for a night to us, well, i digress, good luck and hope it helps</P>

Quik

learn from me. i have svo fans out of a turbo car. with under drives. i have a hard time charging with the lights on at night.

FiveOhNo

i already have problems with my headlights dimming with underdrives...how are they supposed to help the amperage?</P>

Quik

underdrives dont help the charging at all. they actually cause the alt. to spin slower.

horatio102

You can put a smaller pulley on the alternator itself and it'll spin faster. Since it's a smaller pulley some people mistakenly think of it as an underdrive pulley, but really you're overdriving it. Stock motor you're probably ok, but if you rev up to 7k or whatever you might fry it. A matched overdrive alternator pulley with an underdrive crank pulley will 0 out the effects on the alternator and it'll be like stock (but less mass to turn usually).

Quik

i never thought of that i have a larger pulley on my alt. it came with the bbk set.

makarovboy

Believe me, if you do any driving at night, or commute, with the electric fan you need a larger alternator. I installed pulleys and an electric fan, and it doesn't work off the stock alternator. After two batteries and finally blowing up the diodes in the alternator, I switched to a 140amp powermaster 1 wire alternator and have had no further problems. On a rainy night in commuter traffic, with the defroster, fan, lights and wipers going, you'll be glad that you did.