dont know much about them. pros/cons?
I was always told that the ones without harmonic balancers adversely affected your engine long term.
Otherwise I have one on my vette, and with a large cam my lights dim at idle. If you have a huge stereo you might have a problem.
It turns your accessories at a slower speed in theory giving your motor 4-6 more hp. I don’t think they are ever needed on any car, don’t use them if you have a system or a lot fo electronics bec underdrive pullies barley drive the alt. enough to run all the foctory items on the car
don’t replace a factory harmonic damper with an undamped pulley
I definitely wouldn’t do one on the F20c.
i should specify this is for a small block chevy. 383 4 bolt .030 over on :tspry:
I had one on my LS1 it was after market and was fluid dampened…Seemed to make it quicker.
got an unorthodox udp on my neon, def felt a small difference, and i bought it used for 50$, also got better gas mileage
cons: doesnt apply to me, but doesnt turn alt as much
fix: buy an overdrive pulley for the alt
verdict: 50 bux for 2-4hp is a good deal
On DSM’s i know an UD pulley is bad. There would be no balance, nothing better then a oem harmonic balancer. That way you won’t risk it. Or a expensive fluidampr harmonic balancer.
a stock LS1s is fine with a UD. There only balanced at I forgot, low 800ish rpms for smoother idle. And its the fully assembled motor, by drilling some 1/4 holes in the balancer. Witch has no keyway or way to indexing it to repeat it, on the crack snout if you ever remove it. They only show a 0-5whp gain on a dyno but their always a least 1tenth 1mph faster at the 1/4.