OK, i'm interested in getting a UDP....most likely the one in the GD. But a friend of mine said not to becuase my car was harmonicly balanced........well first off he wasn't able to fully explain it to me at the moment and said it would mess up my engine.

What exactly is this? Also, how can it mess up the engine? I don't understand

 

I like crack on my morning cherios. I think your friend does as well.
J/K

 

Here's some info for the Harmonic Balancers and UDP. Harmonic balancer: The harmonic balancer, or vibration damper, is a device connected to the crankshaft to lessen the torsional vibration. When the cylinders fire, power gets transmitted through the crankshaft. The front of the crankshaft takes the brunt of this power, so it often moves before the rear of the crankshaft. This causes a twisting motion. Then, when the power is removed from the front, the halfway twisted shaft unwinds and snaps back in the opposite direction. Although this unwinding process is quite small, it causes "torsional vibration." To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft that's causing all the trouble. The balancer is made of two pieces connected by rubber plugs, spring loaded friction discs, or both.
When the power from the cylinder hits the front of the crankshaft, it tries to twist the heavy part of the damper, but ends up twisting the rubber or discs connecting the two parts of the damper. The front of the crank can't speed up as much with the damper attached; the force is used to twist the rubber and speed up the damper wheel. This keeps the crankshaft operation calm.

The factory pulleys on today's late model cars (from 1986 to Present and sometimes even earlier depending on the vehicle) serve two functions. First and most importantly they are designed to reduce or eliminate the audible noises herd in the cabin of the car that the accessories (alternator, air conditioning, power steering, and air pump) make when the engine is running. This fact exhibits the factory fanaticism about making the car quiet for the occupants (i.e. the use of resonators in the intake to quiet intake noise, all aftermarket intakes eliminate these resonators). It has nothing to do with engine function or longevity. The second function of late model crank pulleys is torsional damping. Torsional damping is necessary due to the excessive diameter and weight of the factory crank pulleys. The design of the underdrive crank pulleys eliminates the need for any torsional damping for two reasons. One, the diameter of the crank pulleys is smaller than the original designs, in almost all cases smaller even than the rubber torsional ring, therefore effectively reducing the force the accessories have on the crankshaft. Second and most importantly is that the pulleys are significantly lighter than their OEM counterparts (anywhere from 3 to 11 lbs.). This weight loss dramatically reduces the stress exerted upon the rotating assembly by the excessively heavy factory crank pulley. Hopefully this
will help.

Mike

 

The crank pulleys on the VQ series motors are not harmonic balancer, but they do have a rubber ring sandwiched into them which serves as a vibration damper. If you install the UDP, you will notice a little more engine noise and slightly more engine vibration. On autos it's not as noticeable, but on manuals, you can feel some extra vibration coming thru the clutch. On WOT acceleration, you'll feel the engine a little more. The 3.5 VQs are a slightly different animal in that they're drive-by-wire so you won't feel any vibration coming thru the accelerator and the 3.5 VQs aren't quite as smooth as the 3.0 VQs so the increase in vibration might not be as noticable.

Running an UDP on a VQ motor is fine. I've never read of one failure on a VQ related to a UDP. The motor is internally balanced so UDP shouldn't be a problem.

The OEM crank pulley weighs ~4lbs. The Unorthodox UDP weighs ~1.5 lbs.


Dave

 

Like everyone else said, our VQ's are internally balanced.

 

Thank you gentlemen.

Guess that answers my question and confirms i'll most likely get that UDP