I just recently put a set of custom built ss test pipes, gutted the pre cats., stillen intercoolers, and a greddy profec B boost controller and i can really hear the blades of the turbos spool.. it seems to really scream on the driver side.. maybe cause im on the drivers side.. who knows but is this normal.. i have stock turbos.. ill try to get a video asap swo that u can hear it

 

This is normal, you should hear the turbo's spool when you get a set of downpipes taht aren't stock gutted, then if you get the tubular manifold hehe it's a great sound.

 

That depends on the sound. Since he's not descriptive enough, we don't know exactly what he's hearing.

Not only to turbos get significantly louder right before they die (it's called "turbo death-whine"), but if he's hearing the blades scrape against the housings, they might actually be dead. (And don't say that can't happen, because it happened to me twice... once was my drivers side GT2530, the other time was my passengers side GT2530.)

But generally, yes, turbos are louder with higher flowing precats.

By the way... was there even a question in this? Are we to assume you want to know if it's normal?