So I've seen a ton of people doing the magnaflow x pipe mod on rep HKS setups but is it necessary or at least recommended on the authentic ones? Mind you I'm paired with art pipes as well. Perhaps something from motordyne instead of magnaflow?

 

In at least some cases, I would say it is much more necessary than for replica's. Replica's are only to cut out on the drone a bit, look up I believe Gary's post about his authentic hks and the actual manufacturing flaw his authentic had that imo requires fixing via x-pipe replacement. Now does every hks have this problem? Who knows, most won't check like Gary to see if their authentic is flawed.

 

Makes sense. If I remember correctly some my350z guys were opening theirs up as well