underdrive pullies?
 

A friend of mine put underdrive pullies on his car, and I was considering putting them on mine. Are they something that would make a whole lot of difference horsepower wise, or would I just be wasting my time and money?

I put the Ford under drive pullies on. It did make a difference. Its not a huge difference, but I did noptice more power. Especially at higher RPM's.

You will notice a little bit of improvement in performance, but you'll have problems with charging from your alternator. (I speak from experience)

If you install underdrive pullys, I HIGHLY recomend doing one of the following....

1) Only get the crank and/or waterpump UNDERdrive pullys and get an OVERdrive pully for the alternator.

2) Upgrading to the G3 alternator (130amps). (you may still have to get an overdrive pully for this one, I had to)

Choice 1 is the easiest and cheapest. Choice 2 will be better if you have a large stero system you would like to keep thumping.

I recomend getting March Performance pullys. :)

If you decide to upgrade to the G3 alternator, let me know and I can provide you with detailed instructions on how to do this. :D

I guess it all depends on the make. I bought mine from Ford and had Ford install them. They have been in for 7 years, with the original alternator and have had no problems at all.

I run all three (water, crank, alternator) pulleys and got mine from March. At idle the alternator voltage is a little low, but it has never caused me any problems. It seems like everyone has a little different experience with pulleys and charging.

I run the ASP three piece set, they said that I might have charging problems if the motor dosen't idle at least 950 rpm, I haven't had a problem yet.



1990 LX 351w 475 hp with 451 ft/lbs

I had underdrives on my old 91 GT and didn't have a charging problem. The voltage was a little low at idle but at speed, the voltage was fine. The battery never died on me.

For ~$80 you can't beat em'

I've had similar experiences. At idle, with the lights on and the stereo running the voltage does drop, and I have the 130 AMP alternator (SN95 5.0). Once your running even at low RPM no problems what-so-ever.

im running two 900watt subs with my u/d pullies with no problems whatsoever...ive got the bbk ones...they look nice too :)

i noticed a touch more power and much better highway gas mileage! i do a lot of highway driving (to and home from school) and it used to take me 3/4 tank to drive uf to home, 200miles (did it about 25 times roundtrip)....and 3/4 was my best average....and never did i make it in 1/2...no matter the conditions of my driving...first trip with em on...i made it in half a tank....weird! :D but i loved it...