ok seriously...what's the deal with lightened pulleys?
 

I searched and searched....but found only mixed answers.....
some think it's a good idea

and some think it's trouble...




so finally....is it good or bad?

I only know of unorthodox who makes them...

Thanks

There is a big difference between lightened pulley and underdrive pulleys. Under drive pulleys tend to reduce you accessories such as your AC and your alternator. They are designe for race use where these parts do not matter.

A lightened pulley just take out rotational mass kind of like a lightweight flywheel. It will reduce the rotational mass of the pulley unleashing power from your motor. The perrin lightweight pulley is a nice on because it is the stock size but very light compared to the stock pulley.

Ben

I have had good results with my UR Crank Pulley with no adverse effects purchased from GSC Motorsports.

Sounds to me like you got the lightened pulley instead of the underdrive pulley set offered by UR. Which really for a everyday driver is the best option. {thumbup}

Ben

i had lightened underdrive pulleys on my mustang. improves throttle response a lot. drawbacks are cuz of the lower spinning alternator at idle it would charge enough so tended to run off the battery charge for help with headlights and a/c on so in the rain or at night had to watch the battery charge meter so it didnt die in long periods of traffic, also the a/c ratio meant the ac didnt blow as hard or as cold. but hell wat did i care it was a convertable who needs air and idling isnt ur friend.

Lightened and underdriven. Just the crank. Def. smaller than stock, that's why you have to get a shorter belt.

Problem is the stock crank pulley has a damper in it, without it, it is possible to have crank problems and your engine goes bye bye and the gain is what? 5whp?

damper = harmonic resonator i think its called im sticking to stock right now...Untill a FULL bolt up kit from UR (underdriven with the resonator and belt) im sticking with stock

^^ that's what I mean...

this crank problem thing........
how does this happen?

Stock pulley is your best friend on the motor, I wouldn't mess around with it.

Harmonic Balancer

Harmonic Damper not Balancer. :)

...thats not what the part number cross reference calls it. LOL

:lol: If Mitsubishi were smart they wouldn't be losing billions of dollars every quarter. :lol:

Balancer is old school from when engines were externally balanced.
Just poor terminology like alternator, WTF is an alternator. :lol:
It's a generator but since they moved the voltage regulator inside people started calling it an alternator.

The two important issues that have been identified on this board both relate to the deletion of the harmonic dampener rather than underdrive or not (yes underdrive may not work for you if you have high eletrical accessory demand): One is possible wear of crank bearings the other one is essentially harmonic imbalance being interpreted as knock activity by the ECU and dialing back of timing and horsepower loss as result.

One thing I still remain curious about is why the harmonic balancer is so crucial on the Evo engine, as I have run other straight fours with undampened underdrive pulleys successfully though they didn't have a harmonic dampener from the factory. Is there anything that makes the 4G63 vulnerable to harmonics?