It's not off balance. But, it may allow for excessive high RPM vibration that could cause excessive wear or damage for your crank and associated parts.

 

1. THIS PULLEY IS NOT LIGHTER THAN STOCK: This billet crankshaft power pulley has a REDUCED DIAMETER to minimize the horsepower robbing drag of the alternator and air conditioning compressor. IT DOES NOT FIT AN LSJ READ ON"
This crank pulley would not fit the 2.0L LSJ. The naturally aspirated ECOtec engines (L61 and LE5) have a 6-bolt crank, while the boosted ECOtec engines (LSJ and LNF) have an 8-bolt crank. The GMPP crank pulley is made for a 6-bolt crank. The purpose of the billet crank pulley is to withstand the rigors of racing applications that involve extended time on the rev limiter.
2. Smaller supercharger pullies ahve nothing to do with the crank pulleu
3. Victory Red did hurt his car with a lite wt crank pulley
4. Harmonic dampers are good.
5. Ecotec is fine at the crank nose until you screw with it MAKE IT LITER and get more power
6. Lite pulley tears up crank timing gears. SEE #3
7. The article there has a source quoted at the bottom: I suggest you buy the book.
8 MEH

BILLET DOES NOT MEAN LIGHTER. GM PULLEY IS NOT FOR LSJ. ARRGGHHHH

 

we already had this talk
lol

 

FINALLY Good one.Maxim rocks. I will run an exedyhyper single, keep it to 7k max my car will last a long time.

 

 

as area said were already past that.....

 

For what it is worth, I have both built my fair share of race and daily driver motors and broken them. (cranks, blocks, pistons, rods, ect.) In my life time I have not seen a failure due to an under drive pulley or light weight pulley setup.

Now with that being said, I have seen excessive wear on cranks and journals because of the incorrect weight off set on flex plates / flywheels. But that is extremely noticeable due to excessive vibrations. It feels like the motor is trying to come apart from the inside.

I noticed the comment about creating crack seal leaks over time. That happens with out under drive pulleys just as much as it does with them.

Unfortunately this will be one of those topics where until a completely stock car with only a lightweight pulley grenades itself, it will be a debate.

Also FWIW, an under drive pulley on a S/C setup would create less boost from a pulley upgrade. Under drives are designed to slow the belt rotation and in theory free up HP. You typically see poor charging, power steering response and coolant flow with the more aggressively (smaller) crank, alternator and water pump pulleys.

 

im with you.

I mainly want it just to get through the rpms faster

 

weight is the key to it.

want to get through the rpms faster? add more power.

 

i remember this discussion.

on a different forum.

 

lol i know that but when i have my build where i want it, which i have just a few things to button up im planning on doing it with whats there

 

QFT!

So is a simple clutch upgrade going to cause these types of problems, IF the stock flywheel is kept (resurfaced, or replaced with OEM part)? I am thinking it would not, but I want to make sure my brain is functioning correctly.

 

I just want to clarify sdomething here for myself. Hopefully qwik or area can confirm or correct this.

Neutral balance shafts/balance shaft deletes are completely safe because:
1: it is not attached to the crank, it is merely driven from the crank, like a typical accessory would be
2: stock shafts aren't balanced in the first place
3: they work by creating vibrations (that just happen to be opposing vibrations caused by the engine, making the ride feel smoother) and not dampening existing ones
4: they effectively add an equal but opposite stress to the equation, and since they do not help stabilize/balance the rotating assembly, removing them will do no more than remove the added stresses and reduce load placed on the crank (at the cost of no longer having these opposing forces, so you will feel more vibrations while driving the car)

This is how I understand it. Is this correct?

thanks for the post by the way Area. clarified a couple things for me

 

Thank you kind sir.

Was always curious about these kinds of modifications.