Originally Posted by Mora

Well, in my opinion, choice of HFC better solution has 2 main problems:

1) Rasp
2) Hp gains

1) If you don't like raspy tone, F.I. HFC is the best solution. Watch on youtube and you will agree with me (YouTube - 370Z Cat Back W/HFC at the end of the video)

2) Here the situation is critical... Berks and F.I. has the same cells count (if i'm not wrong) But the gains in terms of power are very different. And this is very strange in relations with cells count. Berks HFC gives more power than F.I. test pipes (and this is impossible). Consider that F.I. test pipes have arround 4 hp more than HFC... So berks results are a little bit pumped? Maybe....