Just had my Nismo CAI installed yesterday and it sounds great at the higher rpm's. I was behind my neighbor in his BMW Z3 roadster and he said it sounded mean as I was approaching him on the interstate. It is the 350Z intake.

 

what else can you add for more power? Injen claims 11 hp? is that true? Nismo only 5.5?

 

They all are pretty much the same...I can tell you the number is a lot closer to the 5.5 than 11...11 sounds like marketing BS to me...A less restrictive exhaust will add another 5-10...

 

Wellz...personally i feel in fact lose HP and no big deal in sound before 3000, but after 4000 it sounds great.