When I was NA I had installed a UR lightweight, stock size pulley set. When I went SC, the crank pulley was removed and so was the idler pulley as HKS has a specific replacement pulley. However, I believe the alternator lightweight pulley is still installed.

My question is are lightweight accessory pulleys a bad idea when FI, or does it not really matter?

I know a lightweight crank pulley is not recommended, but have not read any info on accessory pulleys and FI.

I am likely going to be changing crank pulleys soon, so if I need to address the alternator pulley I will. I have been having some issue with belts and tension (some slip/having to tighten belts), but am not sure if the UR alternator pulley would have any effect on this.

thanks.

 

I ran the UR alternator pulley and ATI and had no issues, but ended up taking it off so I could sell the UR set.