Just installed the Helix Hi Flow cats this morning on my G35 Coupe, and figured I'd shoot a short video since someone might be interested in this. Install wasn't too bad, but I had to hammer the frame a little underneath cuz the cats were making contact with it . Also note, I do have a Gruppe-S Y-pipe, Z tube, and a Greddy drop in air filter, but the Y-pipe back portion of the exhaust is stock.

The Video:
Right click and Save as

First part, starting and revving in my driveway.
Second part, backing out and driving down the street (stupid VDC was on) and back (turned VDC off) past the camera, than back again. And yes, I scrape my front lip as I pull back in

 

Great video!

I wonder how these will sound with the Injen straight tip. Did you feel any performance gain?

 

holy crap.. that sounds great!

 

Nice vid man, where in NJ you at?

 

GQ: Yes I felt a very noticeable gain from the cats. Best mod I've done so far.

DomZ: I live in Rockaway NJ.

 

wow what kind of bird was that cuz does bird sound great!
nice vid

 

Haha, yeah I didn't even notice the bird till I was editing the vid. What I wanna do to that bird

 

The clip sound great, thanks.

How much do the Helix goes for, and will it pass the visual test? Does anyone know how will it compare to the Crawford or Kinetix HF Cats in terms or sound and gains?

I plan on adding a HF cat, and will be getting a new y-pipe with my stock exhaust as well.

Thanks,
Baron

 

Sounds very good. I like the throttle lift sound.

I know your neighbors "love" you. HAHA

 

zoundz awesome

was it a perfect bolt-on? had to modify anything?:

 

how did u bang out your floor boards with a hammer? or and air chissle? i ahve to do it tomorrow morining and curious whihc route to take i have ultimate racing hi fos and there hitting my floor boards and under acclereation vibrates

 

Does every hfc make that sound when you take your foot off of the pedal? Sounds sweeet...!

 

Monsta: I usually don't drive like that in my neighborhood, just for the vid.

jkoc: Only modification needed was to bang out the frame underneath a little bit to make clearance. I've heard that Helix has switched to a smaller cat that may not require any modification like this.

enhanced250: I just used a regular hammer and started bangin away. I didn't have to clear much room, but I can sometimes hear the cats make contact with the frame. I may eventually have to get under there and bang it out some more.

 

Whered u buy these, and how much did they run.

 

I bought these from Gruppe-s for $480 shipped when they first came out.

 

That sounds pretty dang good! I cannot detect any raspiness at all from the clip.

 

VERY NICE...

Another month until I install mine...

Looking forward to the exotic sound!

ps Love the bird, keep it in there, it adds a little humor to the vid...

 

Sounds really good!

I notice an almost backfire like noise in the clip when you are revving up...between 10 - 20 sec of the clip.

I can't check myself right now since i'm at work, but does our stock exhaust have this same noise revving up?

Also, I just assume you didn't do a 3" to 2.5" cone adapter to this setup. From sound of the clip, it didn't sound like there was any annoying noises that the turbulence would cause. Could you give some feedback you might hear from inside your car (rattling, exhaust leak like tinny noises)?

 

You can't hear it outside the car, but I think I may have a small leak. For the first minute or so, there's a faint sound that sounds like a leak, but it goes away once the pipes heat up. Probably just gotta get under there and retighten the bolts

And no, I don't have any type of reducer in the midpipe. I'm trying to decide if I want a catback, or if I'll get a custom 3" midpipe made that reduces down at the rear by the muffler. I kinda like the way it sounds now, so I'm leanin towards the midpipe only.

 

I'm about to put my hfc and ypipe on, that's why i ask. I wonder if there's any power lost from the turbulence?

If you want a much cheaper alternative to the expensive b-pipe replacement, here's a really useful thread.

http://www.g35driver.com/forums/showthread.php?t=41690

EDIT:
LOL, I noticed that you already posted in that topic. Sorry about that.