I have been trying to decide on which high flow cats to get and have narrowed it down to the Fast Intentions Resonated HFC and the Fast Intentions Non-Resonated HFC. I currently have a Stillen Catback exhaust and want it to be louder but not too raspy. If a muffler delete is a 10 and my current setup is a 6, I am looking to be at about an 8 on volume 😂. I don't mind if it is a little raspy, just not to the point where it's annoying. Also if anyone has any dyno experience with these that would be good to know. So should I go with the non-resonated or will the resonated also make my car decently louder?

 

I dunno, recently on FB groups I saw FI breaking at the weld seems. I'd figure out that part first. It has put a pause on me mentally.

 

Does FI HFC have a support brace or flange or whatever you call it?

I know the RHFC does not.

If FI HFC does not have that, I would just go with a Z1 or berk.

 

funny i saw the same post and has me scratching my head. I had mine on my previous car that was totaled in July and never had an issue. Had it on only for about a year though.

 

I thought about the Z1 or Berk but I heard that people were complaining about them being too raspy and some people said that they got CELs with the Berks.

 

Check Rochester build thread (all gazzilion pages) he had a support added to his FI set.
FWIW I have RTPs that don't have the support and still fine for a couple years.

And good point regarding the CEL, the FI won't throw CELs as they use the counter flow O2 port, this is the best setup for no CELs.

 

AAM high flow cats.

 

Or this thread right here which directly addresses the lack of a support bracket:

https://www.myg37.com/forums/g37-sed...tions-hfc.html

 

Thanks I will check it out!