underdrive pullies?

mwingard · 06-18-2003, 12:26 PM

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?

Mass Stang · 06-18-2003, 12:32 PM

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.

cyberstang5.0 · 06-18-2003, 03:04 PM

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.

Mass Stang · 06-18-2003, 03:07 PM

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.

Hethj7 · 06-18-2003, 09:20 PM

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.

kvaught · 06-21-2003, 11:47 PM

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

Stang_Crazy · 06-22-2003, 02:09 PM

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'

95mustanggt · 06-23-2003, 08:53 PM

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.

jj_jonathon · 06-24-2003, 04:16 AM

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!

but i loved it...

06-18-2003, 12:26 PM	#1
mwingard Registered Member Join Date: Jun 2003 Location: Rison,Arkansas Posts: 6	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?

06-18-2003, 12:32 PM	#2
Mass Stang Registered Member Join Date: Apr 2003 Location: Boston, Mass. Posts: 110	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. __________________

06-18-2003, 03:07 PM	#4
Mass Stang Registered Member Join Date: Apr 2003 Location: Boston, Mass. Posts: 110	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. __________________

06-18-2003, 09:20 PM	#5
Hethj7 Mizzou Tigers Join Date: Apr 1999 Location: weston, MO United States Posts: 1,455	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. __________________ 2006 Mustang GT 1990 LX GT-40 motor 262 horsepower, 307ft-lbs (sold but forever loved) 1998 Contour SVT Rice Haters Club Member #244

06-22-2003, 02:09 PM	#7
Stang_Crazy It's never clean enough! Join Date: Jan 1999 Location: Shaler, PA Posts: 1,542	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' __________________ ~Dan 2001 SVT Lightning 89' GT : Taking up garage space and waiting for a buyer... Rice Hater's Club - Member #11

06-18-2003, 03:04 PM	#3
cyberstang5.0 347ci of HORSE POWER!!! Join Date: Jul 2001 Location: Houston, TX Posts: 1,416	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.

06-21-2003, 11:47 PM	#6
kvaught Registered Member Join Date: Jun 2003 Location: Fairfield, Ohio Posts: 22	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

06-23-2003, 08:53 PM	#8
95mustanggt Registered Member Join Date: May 2000 Location: Kamloops, BC Posts: 2,875	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. __________________ 1995 Mustang GT 20016 F150 Lariat Super Crew

06-24-2003, 04:16 AM	#9
jj_jonathon Trisket Join Date: May 2002 Location: University of Florida, FL Posts: ½ Posts: 1,560	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! but i loved it... __________________ University of Florida - Physics Major My 02GT vert Media Center Pics BBK Underdrive Pulleys \| K&N FIPK (Gen II) \| Bullet Grille \| Mach 1 Chin Spoiler \| UPR Interior Parts \| XM Radio \| Audiobahn Subs Ricer Hater's Club Member #1/2 (30) http://www.ricehatersclub.com/

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