underdrive pulleys Good or bad?
04-02-2010, 07:55 PM
#1
Thread Starter
Join Date: Mar 2008
Location: connecticut
Posts: 17
underdrive pulleys Good or bad?
I have heard a few opinions about underdrive pulleys, some say they are a great idea others totally against them because they over work the a/c compressor and other components and of course several say they are good depending on what kind you can buy. I've seen a few posts on here about underdrive pulleys but I'm still kinda unsure. I just wanted some peoples opinions on them and if anyone has them or has used them if you have had any problems or they are perfectly fine. thank you
04-02-2010, 08:53 PM
#3
2nd Gear Member
Join Date: Oct 2009
Location: Florida
Posts: 429
I agree with AdderMk2. The trade off is not worth it. You spin the alternator slower, leading to a discharge situation under heavy electrical load (a/c on high in the summer), and potential cooling problems with the water pump spinning slower. The only benefit you get from those pulleys is when you have sustained high engine speed. They reduce parasitic drag slightly. On a street car, they don't make much sense. Ford has determined the optimum pulley size for your accessories.
04-03-2010, 01:01 AM
#5
i bought a used set for 25 bucks, but i would never pay full price for a set. I myself have zero cooling issues, and my alternator still charges just fine. but i've got a radio and 2 speakers so if someone had a system i'm sure it wouldn't be good to have them. just my 2 cents.
04-03-2010, 06:30 AM
#6
5th Gear Member
Join Date: May 2007
Location: Norton, Massachusetts
Posts: 2,166
Ive got them. They were on the car when i bought it. My alternator is upgraded. I also have an aluminum radiator and electric fan. So i have no cooling problems. Personally i too think there a waste of money myself. I may change them later to some stock pulleys.
04-03-2010, 02:43 PM
#8
2nd Gear Member
Join Date: Sep 2005
Location:
Posts: 246
No problems with mine, i have no AC. but i do have dual 12" fans from a 99up v6 cougar
The volts read lower at idle, but i havent had any problems from that.
Yall can call BS if you want, i dont care because i know what they did for me.
I bought the kit from latemodelresto, It included the pulleys, AC delete, belt, and it also deletes the smog pump.
I put these on and knocked off 3 tenths exactly at the local track. (1000ft)
I guess it was the pulleys and reduced weight
The volts read lower at idle, but i havent had any problems from that.
Yall can call BS if you want, i dont care because i know what they did for me.
I bought the kit from latemodelresto, It included the pulleys, AC delete, belt, and it also deletes the smog pump.
I put these on and knocked off 3 tenths exactly at the local track. (1000ft)
I guess it was the pulleys and reduced weight
04-03-2010, 11:47 PM
#9
4th Gear Member
Join Date: Jan 2007
Location:
Posts: 1,999
I agree with AdderMk2. The trade off is not worth it. You spin the alternator slower, leading to a discharge situation under heavy electrical load (a/c on high in the summer), and potential cooling problems with the water pump spinning slower. The only benefit you get from those pulleys is when you have sustained high engine speed. They reduce parasitic drag slightly. On a street car, they don't make much sense. Ford has determined the optimum pulley size for your accessories.
If this happened to your neighbour's brother's friend and the battery went dead. That's was NOT the fault of the underdrive pullies.
Same with cooling. If slowing down your pullies 10% causes your car to overheat. You need a radiator and probably needed one for the last 5 years.
I'm not here to preach how much performance you gain because truthfully it's not much.
It's also nice to slow down the accessories on engines that are now spun 1 or 2 thousand rpm higher than factory.
