Is the VQ exhaust referred to above the same as:
https://g35driver.com/forums/engine-...er-plenum.html

Yes it is and that's a hell of a good price.

This is the sedan version when it was new, mucho shiny goodness. :D

http://farm4.static.flickr.com/3481/...bca2dfcb_z.jpg
http://farm3.static.flickr.com/2456/...5c3a8106_z.jpg
http://farm3.static.flickr.com/2517/...f465e94a_z.jpg

Not my car, but what you see here was almost $1000 shipped when new.

I'm in the same boat. I want to keep my exhaust sounding close to stock, but I also want to open it up a bit to complement the intake improvements (and eventually get it all tuned).

Apparently HFC are the best "bang for the buck" keeping stock-ish sound & emissions, however lcysimon mentioned there are no HFC's with 2" inlet/outlet for the OE exhaust.

What to do? :dunno:

He was talking about the unless on a HR y pipe not matching the HFC. unless that's what you have?

I meant inlets not unless.

Regardless of what Y pipe you use with the OE exhaust, you will run into this issue... Say you get the MD xyz pipe 2.5" inlets and 3" outlet, the OE mid pipe is still 2.5".

So whether it be the HR Y pipe or an after-market Y pipe, you will run into a 2.5" problem unless someone makes a 2" hfc or a 2.5" overall HR Y pipe.

But as mentioned earlier, perhaps the OE mid pipe will resolve the 2.5" to 2" HR Y pipe rasps.

But at the end of the day, opening up headers (I.e. My case of swapping on OE HR headers) would not be as effective since the Y pipe doesn't open up enough...

As such, it goes back to my dilemma / question...

Will OE HR headers+OE cats+xyz pipe+ Nismo S tune make more power or OE HR headers+FI HFC+ HR Y pipe+OE exhaust make more power.

Help me out and I shall buy you coffee :)

Hmmm I didn't realize any of this bc I installed the hks replica at the same time as my berks. I know others have berks with oe exhaust. I need to figure this out bc I'm thinking of putting my oe exhaust back on!

Are OEM cats 2.5" on the exhaust side?

Stock cats are roughly 60mm. 2.25in would be my best guess.

Oh and hint hint art pipes are 2.25in as well. Master Tony determined that to be the most efficient size.

Lol, thanks :)

Looking to get a Stillen catback exhaust, and wondering what (if any) issues I"ll have bolting up to stock cats.

Tony's fairly smart. Not quite "accountant" smart, but not bad for a rocket scientist :)

The OE Y pipe inlets are 2.25" so you only have a .25" difference. I guess most people just bolt their 2.5" HFC to that. I'm wondering how that's possible without any problems? I know people do it but never heard of anyone complaining about fitment of HFC to OE exhaust. I'm wanting to put my OE exhaust back on and keeping the Berks HFC. Does this require some type of modification?

bumping for much needed info.

I'm wondering the same since I want HFC's to HR Y-Pipe. Any rasp/vibrations?

Old video of mine. First part is my car with the HR y-pipe and Fast Intentions HFC's.

What gains did you see upon going with the HFC/Motordyne exhaust over just HFC/pipe?

Btw, really like the Motordyne sound. Not bad at all.