I'm assuming you're talking about the HR y pipe off a 350z (make sure it's off an HR motor, not DE). I use to have that same combo, f.i. HFCs .+ hr y-pipe on stock exhaust, I really liked the sound. It made it a little louder and a deeper growl. You'll gain performance from both parts.

The first part of my dyno video is with that combo:

 

its all the ecu, or get an air fuel tuner

 

Hmm, I'm at work right now and eager to listen to that sound clip but my work force has blocked youtube (damn baaastards lol)... But how do I know the difference between HR and DE? Is there a way to tell, sorry I'm the biggest newb when it comes to exhaust and all that under the car stuff. How much should both these parts cost me? I have a certified mechanic at Nissan that does my mechanical stuff for me if I go directly thru him and pay him alittle cash, so I'm not worried about labor. Thanks in advance

 

HR y pipes come off of 07-08 350z's. They have different pipe dimensions and a better design than the stock DE y pipes. HR y pipe is on the right.

https://g35driver.com/forums/4515278-post568.html

Used f.i. HFCs are a little over $300, like $530 new. HR pipes are getting hard to find now since everyone wants them. I bought mine for $75 last year, and sold it for over $100 a couple months later. I'm sure they cost more now. Maybe your mechanic friend has an extra one lying around?

 

^^Hmm, thanks.. So basically DE is anything 06 or below? I'll take a look if he does, but just curious. What kind of gains did you achieve from this mod? Would adding a 350z mid-pipe also do anything to this set-up?

 

I'm sorry if I'm asking too many questions but how was the noise of the exhaust in-cabin? Stock vs HR Y-Pipe and F.I. HFC? is there a significant increase in volume in-cabin?

I'm also thinking of adding Z-tube with JWT-Pop Charger with the spacer as well in the near future.. Trying to keep my costs minimal as much as I can.

 

Sorry, I never dyno'd that combo. My dyno was to see the gains going from that combo to the MotorDyne catback, in which I gained like 13hp. I don't think there's much difference between the midpipes, plus you'd have to get it extended to fit.

In cabin noise increased a little, but definitely nothing to worry about.

 

Thanks bro, I'm looking around for the HR Y-Pipe and the HFC now can't wait!

 

No problem, good luck!

 

If you're going to shell out 500+ to get rid of the cats, why not go for ART pipes? They've been showing gains over everything out there. If you still want a cat on your exhaust system, you can get that piece for the XYZ.

 

I don't know if you're talking to me because I'm a complete NEWBIE when it comes to the exhaust lol.... So, basically whatever you said went over my head

 

To anyone, I guess, who hasn't heard. Replacing the catalytic converters is a quick way to some extra power, and for a long time it's been test pipes or HFCs, and now there are ART Pipes from Motordyne. They don't have the rasp of standard test pipes, show gains over everything else out there, and cost about the same as a new set of good HFCs like Ultimate Racing's metal pair. They also make a Y-Pipe called the XYZ which has three removable modules available for it; a straight, resonated, and HFC.

Personally, I give a damn about emissions, so I picked up the XYZ w/HFC after I got my ART Pipes so I can live with myself. Having the cat further down the exhaust stream, and only having one, make a huge difference in performance.

It's not the cheapest route, however.

 

Good info. Do you have sound clip of that setup?

 

A ground kit would add some extra fun to your automatic faster tiptronic shifts!

 

I'm afraid I don't have a sound clip, but I'm pretty sure I've seen one or two on YouTube. Here's a few worth looking at:

I do know that the older (Gamma I think) Motordyne cat-back exhausts include the full XYZ (as in, with a module) in the setup, but both the TDX Shockwave v1 and v2 have the XYZ without module.

@atrudeau - Ground kits aren't going to do anything unless something is wrong already under your hood. More for older cars with lots of wear. Sort of like spark plugs, replacing the old ones will bring some life back, but not necessarily add anything.