what the title says....

 

they are a little bigger and run your accessories (alternator, P/S, and A/C) a little slower, freeing up some hp. yes they are worth it.

 

i have heard mixed results some say they really work others say they barely do. does anyone know of some dyno slips of these?

 

i had one on my 90 civic for 2 years, i could tell a pretty good difference in power, as did one of my friends w/ a 93 accord

 

They are actually smaller than stock. As a result, they spin your AC, alternator, PS pump, ect., SLOWER. IMO, not worth the hassle. Besides the expense, there's the chance of a constantly low battery because of insuficient charging from the alternator. As far as gains... you will notice a gain only because you spent the money. In the real world, I doubt it's very significant.

 

<sighs> no, they are bigger. if they were smaller, they would spin accessories faster, in effect losing hp. the crank underdrive pulley is smaller, but not the accessory underdrive pulleys. they do make a difference, and every little bit helps. i just took off the P/S and A/C, and ran a UR (unorthodox racing) alternator underdrive pulley and a UR racing crank pulley(single belt, alternator only) I also had a HUGE battery in the back of my teg, an AC Delco 1000 cranking amp, and it always stayed fully charged, and ive never heard of anyones battery (in good condition) getting low.


[Modified by 22lbGS-R, 9:43 PM 1/16/2003]

 

i have one that i used in my 1995 integra. the car was stolen but the pulley (blue anodizing) is sittin in my garage if you are interested... $90 and its sold.

 

You are correct, of course. The driven pulleys are larger. The crank pulley, what I was refering to, is smaller. BTW, there have been some posts regarding engine damage due to underdrive crank pulleys. Mostly due to harmonic vibrations. I have no direct experience with any underdrive pulleys, so I don't know how common the damage may be.

 

yeah i heard of the underdrive crank pulleys warping the crank an ****...... but i never had a problem, and i was making 409 hp, so i trust them.

 

THe only thing i've personally seen is increased main bearing wear.