Are light weight pulleys bad for your N/A engine? I’ve been thinking about getting one because I plan on getting a tune soon and was wondering if it could help with at least +5hp. Asked one of my friends and he said the lightweight crank pulley could mess up the timing. Is this true?

 

They will not mess up timing, but they have other issues.

 

It reduces harmonic balancing. The heavier weight OEM pulley is the better thing to keep, or to upgrade to the ATI damper or something similar.

 

https://www.evoxforums.com/threads/w...et-junk.50463/

It has failed in other cars. The 350z obviously is a different platform.

 

Its not "bad" but it is not good. You have to remember the crank pulley (Harmonic Balancer) was designed to help negate the internal vibrations you get from the V engine. With out the sufficient dampening those vibrations make it to the bearings shortening their life.

 

(Didnt know you should boil the hub of the balancer and slide it on hot)

 

In theory there's less rotating mass, but as stated above it's then simply a flywheel not a harmonic balancer.