I am having a hard time grasping the exact job of an underdrive pully.:doh:

it slows down the speed of the accessory relative to engine speed thereby reducing the amount of power it uses.

For stock engines it is not necessary right?

For stock engines it is not necessary right?
By itself, You won t be able to tell the difference. Its one of those things you can do in conjunction with other modification to get every bit of Hp available.

Reduces accessory drive torque load on the engine.

I am having a hard time grasping the exact job of an underdrive pully.:doh:


It will slow down the water pump, power steering pump, and alternator; thus freeing up a few horsepower. The underdrive pulleys are made for those who race their cars and have a need to squeeze out every bit of horsepower. If you don't race your car, I wouldn't advise you to buy one.

:iagree::iagree::iagree:

Aren't there liquid filled ones too?

Aren't there liquid filled ones too?
?????? liquid filled ??????

Aren't there liquid filled ones too?

yes
Fluidamper

yes
Fluidamper
Those are harmonic balancers that reduce vibration,..not underdrive accessories

And I thought they were the same thing with different charactoristics.

Those are harmonic balancers that reduce vibration,..not underdrive accessories

tell me you are kidding :rofl:
I'm guessing everyone else knows what I'm referring to

but....

just for reference

http://www.fluidampr.com/IMAGES/PARTS/720151.jpg

tell me you are kidding :rofl:
I'm guessing everyone else knows what I'm referring to

but....

just for reference

http://www.fluidampr.com/IMAGES/PARTS/720151.jpg
tell me you re kidding, THE SILICONE GEL INSIDE HAS ABSOLUTELY NOTHING TO DO WITH CHANGING RPM OF ACCESSORIES.It is simply to absorb vibration, ! You still must get a smaller pulley to change anything. or a larger on on the accessory itself. The only thing fluid changes rpm relative to engine speed is the old fan clutches.Where fluid is forced thru a valve as speed increases and then slows the fan. that DOES NOt happen on a gel filled damper.the under drive still has to be accomplished by the diameter of the pulley attached.

DUH , thank you captain obvious.
I was just pointing out that there is a liquid filled dampener

tell me you re kidding, THE SILICONE GEL INSIDE HAS ABSOLUTELY NOTHING TO DO WITH CHANGING RPM OF ACCESSORIES.It is simply to absorb vibration, ! You still must get a smaller pulley to change anything. or a larger on on the accessory itself. The only thing fluid changes rpm relative to engine speed is the old fan clutches.Where fluid is forced thru a valve as speed increases and then slows the fan. that DOES NOt happen on a gel filled damper.the under drive still has to be accomplished by the diameter of the pulley attached.

DUH , thank you captain obvious.
I was just pointing out that there is a liquid filled dampener


I think fishslayer simply misunderstood what you were saying. No harm intended. Fluid filled dampers have been around seemingly forever as Cummins and Caterpillar engines were using them back in the early '70's. Then Detroit Diesel began using them by the late '70's. And then they were "invented" for cars in the '90's.

I think fishslayer simply misunderstood what you were saying. No harm intended. Fluid filled dampers have been around seemingly forever as Cummins and Caterpillar engines were using them back in the early '70's. Then Detroit Diesel began using them by the late '70's. And then they were "invented" for cars in the '90's.

I'm not sure when I first saw one but it was WAY before the 90's:givemebeer.sml:

tell me you re kidding, THE SILICONE GEL INSIDE HAS ABSOLUTELY NOTHING TO DO WITH CHANGING RPM OF ACCESSORIES.It is simply to absorb vibration, ! You still must get a smaller pulley to change anything. or a larger on on the accessory itself. The only thing fluid changes rpm relative to engine speed is the old fan clutches.Where fluid is forced thru a valve as speed increases and then slows the fan. that DOES NOt happen on a gel filled damper.the under drive still has to be accomplished by the diameter of the pulley attached.

All razzing aside, do these offer alot of pros to a stock engine?:thumbsup3:

All razzing aside, do these offer alot of pros to a stock engine?:thumbsup3:
not much

:15:not muchI agree

:15:I agree
See, I knew we could agree on something.lets keep it up

See, I knew we could agree on something.lets keep it up

:thumbsup::thumbsup:

If properly cared for, a viscous damper will last almost forever. It's very important to never drop/dent one as that would impede the inner ring's ability to float in the silicon filled outer housing. The harmonic damper dampens the crankshaft's tortional twisting motions as the power pulses are generated. A good damper, although being a load on the engine, can actually improve horsepower as it dampens out the tortional vibrations that disrupt accurate ignition timing.

10 extra HP for all that work and money is not worth it IMO.

10 extra HP for all that work and money is not worth it IMO.

it is if the motor is already apart and it's seriously modified, otherwise :iagree:

:goodpost: absolutely.