u/d pulleys

[rollin315s]

Are fox and sn95 u/d pulleys the same?

 

[ivan12]

Nope, specific. I'd also recommend against them, they usually cause more trouble than the 4-5 HP you gain

 

[Twista]

Stay away unless you hate your alt and battery
http://www.youtube.com/watch?v=nO9GwZyJ1T0

 

[rollin315s]

Y do u say that? We trouble could they cause? Btw I would only be using the crank and w/p

 

[Musturd]

I run them never had a problem with them

 

[rz5.0]

I remember when UDP were on the must upgrades for a mustang.. Now everyone is afraid of them..

 

[ttocs]

by swapping even just the crank pulley, you will also slow anything down that is attached to it. When this happens the alt also slows down puts out less voltage and also does not cool itself as well and leads to overheating and failing of the regulator. Because th ealt puts out less voltage then it should now when idleing you can also mess a battery up from it. You will not notice any gain in performance but you will notice at night that you lights dim and the voltage gauge is just barely working. Later when you start to add some reall add-ons you will want to ensure that everything is operating the way it was designed too, would you really want the cooling system slowed down after installing heads/cam?

I had underdrives for maybe 8 months. Only good thing about them was that I bought them used and was able to sell them for the same price to another sucker. I have NEVER thought once since then, man I wish I had those..... Save your money.....

 

[DFG_magic]

U/D pulleys are fine if done right. I have ASP under drive water pump and crank pulleys and an overdrive alternator pulley. No problems whatsoever. Short belt smog pump delete, still have AC. I run an 87.5" belt. 875K6 to be exact. Tensioner is still well within spec. Car gets up and revs a lot easier with the pulley set. Don't be afraid of U/D pulleys. Just understand what your car needs to operate efficiently and adjust accordingly. Most u/d pulley instructions usually advise to bump your idle up a bit to keep the alternator charging and water pump cooling properly. It helps to be able to adjust your idle via tune as well.

 

[Twista]

Y do u say that? We trouble could they cause? Btw I would only be using the crank and w/p

That video i posted is only with the Crank and water pump UD pulley. You can see when i rev the voltage jumps up. When the rev is over and it starts idling again you notice the volts drop again.

Also look how bright the cluster is when i rev then it gets back dim after the rev is over.


Now this might not effect a race track car, but on a DD that uses heat during the winter and a/c during the summer it will have a huge effect on your voltage.


I killed my battery while burping my radiator with the car running @ idle for 30 minutes with the heater on full blast with no revs.

 

[Twista]

U/D pulleys are fine if done right. I have ASP under drive water pump and crank pulleys and an overdrive alternator pulley. No problems whatsoever. Short belt smog pump delete, still have AC. I run an 87.5" belt. 875K6 to be exact. Tensioner is still well within spec. Car gets up and revs a lot easier with the pulley set. Don't be afraid of U/D pulleys. Just understand what your car needs to operate efficiently and adjust accordingly. Most u/d pulley instructions usually advise to bump your idle up a bit to keep the alternator charging and water pump cooling properly. It helps to be able to adjust your idle via tune as well.

Interesting. I might uppen my idle so i can hear my piss quiet exhaust more @ idle of course to help my pulleys in the long run

 

[95opal]

I have run pulleys on every stang ive owned since 1989 and never had battery issues or overheating problems. After a few cars the diming of the lights and cluster got annoying so I just leave the stock alt pulley on....no more dimming. I have the ASPs on this car with no issues. Whatever you do just make sure your buying aluminum pulleys.

 

[Paul]

If you want to underdrive your crank and water pump, you can just buy an overdrive pulley for your alternator. Then you'll still be charging fine. Aeromotive sells them.


I didn't use underdrives on my SN95 because it's too hot in Phoenix and I needed every bit of cooling capacity I could get.

Paul.

 

[ttocs]

I think what it comes down too is that if you spend alot of time idling that you can run into issues. When it is up in rpms it is still cooling/charging just fine but at idle it is barely meeting the minimum.

Best advice I can give if you are dead set on getting them is buy them used and keep your stock pullies in a safe place incase you do not like them....