do you guys recommend the stillen z-pipe for our g35 sedan? i was told that with z-pipe and stillen intake our g35 can gain 11+ hp, is this true?

You're in the wrong section. This is General Discussion.

Start here:

https://g35driver.com/forums/intake-exhaust-23/

or here:

https://g35driver.com/forums/search.php

There are better NA options out there.