so I purchased a 04 redline with the intentions of building it. Drove it for the first time yesterday and the only complaint I have is it lacks power up until about 5100 rpms. She's bone stock, about 150k miles. Once it hits 5100 it pulls hard. Is this normal for the lsj motors?

 

Can you confirm how much boost it's making?

 

This. We don't know how your butt dyno was calibrated. That said, it could need a tune-up.

 

Can't say I've ever noticed my Redlines lacking power like that. Might be worth going over this car seeing you just got it and maybe you don't have any history on it.