Smaller Pulleys on the Engine?

Reply Subscribe

Thread Tools

Search this Thread

05-08-2005, 12:00 AM

Grandmaster

1st Gear Member

Thread Starter

Join Date: Apr 2005

Posts: 102

Smaller Pulleys on the Engine?

I was told that if I put a smaller pully system on my car that it would increase horsepower? I've never heard of this, is it true?

05-08-2005, 12:26 AM

Chris C

2nd Gear Member

Join Date: Nov 2003

Location: Colorado Springs

Posts: 280

RE: Smaller Pulleys on the Engine?

They are called underdrive pullies. They increase HP by slowing down the accessories on the car like the alt, water pump ect. I have seen dyno results showing anywhere from 5-15 HP depending on how much they are slowed down.

05-08-2005, 12:37 AM

Pure5.0

3rd Gear Member

Join Date: Mar 2005

Location:

Posts: 699

RE: Smaller Pulleys on the Engine?

I second Chris.

And on top of that I will add...friction is the number one robber of HP. The more friction you have the less HP you will get from your engine. Accessories on your serp belt create a certain amount of friction. Underdrive pulleys because they are smaller don't require so much power from the engine to turn them. Because of this there is a marginal amount of less friction...which means that HP what was overcoming friction is now being sent where you want it to go...the wheels.

05-08-2005, 01:39 AM

luckythirteen13

6th Gear Member

Join Date: May 2004

Location: las vegas, nv

Posts: 9,092

RE: Smaller Pulleys on the Engine?

yes its true. they will also add to the life of your alt. and water pump. because they are slowed down, they dont spin as much which can legnthin their life

05-08-2005, 03:04 AM

Grandmaster

1st Gear Member

Thread Starter

Join Date: Apr 2005

Posts: 102

RE: Smaller Pulleys on the Engine?

Where can I find these kits?

05-08-2005, 05:18 AM

92hatchLX

6th Gear Member

Join Date: Feb 2005

Location:

Posts: 8,439

RE: Smaller Pulleys on the Engine?

summit, 5.0 resto, mostly everyone carries them. I've heard that they do not allow you're alternator to spin quick enough and same for the water pump, doesn't that usually result in a hotter car and a lesser charge in you're battery when you are idling?

05-08-2005, 10:48 AM

bz1111

2nd Gear Member

Join Date: Dec 2004

Location:

Posts: 221

RE: Smaller Pulleys on the Engine?

We have gone around and around on this. The car stays cooler because the water stays in the radiator longer. You will not see a big difference in the dc output, only if you have a moster stereo or something that needs lots of power.

I have a set on my car and i see no difference in cooling or power from the alternator.

good luck

05-08-2005, 12:36 PM

vfast

I ♥ Acer

Join Date: Jul 2003

Location:

Posts: 11,394

RE: Smaller Pulleys on the Engine?

the reason some car heat up is the pulleys expose a problem that was already thier....really the crank pulley is the one that gives back the most hp......alot of this people used a race crank pulley and stock w/p and alt pulleys......I use the 93 cobra alt pulleys which is a lil smaller to help with my charging problems..