What do underdrive pulleys do?

[bonestock3.8DTH]

What are under drive pulleys? And what do they do? Are they the same thing as shift kits? Or what?

 

[JonBeast]

Google is your friend

http://marchperf.com/tiptricks/underdrive.html

 

[blkmcnasty]

They give you simulated horsepower and make your alternator work double time.

 

[bonestock3.8DTH]

Yeah but Id figure yall'd be able to give me more understandable answer or a better sense of direction to look into.

 

[Rice_slayer]

Makes accessories run at lower speeds to reduce drag, thus increasing power. IMO, not worth it, as mcnasty said, it is hard your alternator, and my alternator has enough issues .

 

[bonestock3.8DTH]

Oh I see. Thanks guys! And thats why I asked yall not google hah. Cause yall will give me a real answer not what the company wants to say hah.

 

[JonBeast]

They free up horsepower by reducing drag from your belt driven accessories.

I forget exactly but I believe the alternator u/d pulley is larger than stock and the crankshaft u/d pulley is smaller.

 

[auto_x5.0]

alt pulley is smaller, that's why it causes alot of alt failure. If your spin your engine too high too often it can over power your alternator b/c the pulley is smaller and spins faster.

 

[MustangChris]

http://www.americanmuscle.com/underdrive-pulley-tech-guide.html

 

[Twista]

There a pain in the butt. Voltage drops really low when your sitting idle and lights dim. Once you tap the gas to start moving the lights brighten back up.

I wouldn't get them if my car wasnt already equipped with them.

 

[Mystic SVT]

alt pulley is smaller, that's why it causes alot of alt failure. If your spin your engine too high too often it can over power your alternator b/c the pulley is smaller and spins faster.

No, alternator/water pump pulleys are bigger and crank pulley is smaller in underdrive pulley sets. Alternators tend to go out because they have to try and put out the same amount of voltage by spinning slower.

 

[Brian95SVT]

From personal experience, they aren't worth it. They killed my alt so many times and caused a serious headache. I swapped back to stock and never had a problem (this is back when I had my '96)

 

[bigkeeko]

They lighten your wallet for 2 hp

 

[ttocs]

I had them and was just happy that I kept my stock gauges to put them back on later. They were easy to sell thankfully as well. I would not recomend them, there is better way to get HP with out hurting anything.

 

[Venom351R]

I have them on the Cobra and had them on my GT before that. Never had any Alt issues or charging issues. You can still get the set and just not put the alt one on

 

[ttocs]

and then rather then the 3 hp you gain you might be lookin at 2 hp. Again not realy worth it but keep your stock pullies and you can make your own judgement.