Anybody ever used underdrive pulleys? i have a set but herd that they dont do much at all. are the worth installing?

 

I have March Pulleys......They free up a few horses but other than that not much else. I have had mine for like 4 years and no issues. I do go through a battery every year and a half or so.

 

Why would you get them, but then not want to install them? It takes like 5 minutes to install (if you have a puller) and it gave me a little more throttle response. My battery does get a little low if I'm idling for awhile, but I don't have the alt. pulley, just the crank one. I'd say throw it on, couldn't hurt.

 

They were given to me by a friend who supercharged and couldnt use them , but i herd mixed stories. it has both pulleys, any idea as to the power gains?

 

I bought my crank pulley off a guy that supercharged and couldn't use it anymore.... anyway WS6.com dyno tested with and without a pulley and HERE is the result. Take it for what its worth. I'd throw them on, like I said, its a real simple installation.

 

I have the ASP harmonic balancer pulley andit has gave me a 5-7 HP gain. I would definatly put the pulleys on, HP is HP and you should try to get as much as you can, no matter how small the mod might be!

 

what the hell , I ll throw them on tom. will i need a smaller belt?

 

Uh yeah..... I believe so. had mine so long don't remember.

 

My Z seems to get hot alot quicker than my girls, Ive heard people say that underdrive pulleys will make em heat up quicker. I donno , I do know my girls car is stock and mine has 160 degree thermo and alt + crank underdrive pulleys and mine will overheat way quicker than hers. Altho I do have a fan switch :P.

 

Our waterpumps arent belt driven....

Anyways, the only good pully IMO is the ASP harmonic balancer pully. It replaces the factory damper, instead of bolting behind it. Saves rotating weight and reduces your ratio.

 

Next to the intake pullies are liek the cheapest most obvious mode. THey work and for 99.99 I don't see why more people have them.

 

Also remember that slowing down the accessories slows down the PS pump. That's a decent draw there, and that pump will cavitate over 3500rpm engine speed. By slowing it down, and stopping it from cavitating, you also reduce it's propensity to boil the fluid - which is a problem if you road race or drive very aggressively.

 

What brand? How many?

If you have alt. pulley, be aware that you may need an impact wrench to get it off and on.JMHO

 

I have a little 4cyl engine and after I added mine it pulls very nice in 1st and 2nd, so imagine what it could do for your V8s

 

Is that the underdrive crank pulley (34%) from LS1 Speed, Inc. or the underdrive harmonic balancer (25%). I want to replace the OEM damper. Right now I have an underdrive pulley behind the damper (harmonic balancer).
Thanks!