rico, i agree. i measured a g35 hr and my stock y pipe and they are the same length. being someone who is underneath hr motors all day, i think i can safely say that all hr y pipes, at least on the infiniti side, will be the same, the difference is in the mid pipe section. while i havent been underneath a hr z, i would assume is only slightly different as in the flex section is a bit shorter and the heat shields are a bit different.

 

ok, i want the aftermarket HR Y and the larger midpipe. should i get the new airbox too? is that compatible with my stock MAF sensor wiring?

 

RicoG35x - You'll see when I post pics of the inlet diameter of the pipe I got, its definately noticeable regardless of how much heat shielding there is. That is not even related. I'm talking about the inlet where the cats meet the y pipe. I still don't know what pipe I got...when I have some time I might research it, but I'm past it so I don't really care, when it comes off tomorrow its going straight to the dumpster lol.

 

I can dig it... that's one view we haven't seen yet on here.. end views of the cat side inlets... the G37 pipe looks smaller.. but I can't vouch for that.. never seen one in person.. counting on all the peeps that have them in thier possesion to settle this once and for all... my head is spinning from all of the proliferation of Y-pipes coming out of the woodwork!?!?!

All I know, is that I went from an old school y-pipe to one that looks like the HR y-pipe, WITHOUT the hockey puck hardware.. like what has been stated as the "stock 04 Gx" pipe. (check photo) I have a February 04 Gx... I feel like there might have been hardware changes at the 04.5 mark... which would lead into the 05 model year and now this is the current 04 Gx pipe.. if you order a replacement... almost as if 03/04 (early) models had that ugly short Y pipe.. then from 04.5 on, the revised Y-pipe (puckless).. then in 07.. HOCKEY PUCKS!! (HR)



it still sounds like da S**T!! I love it...!!

 

Yes I did.. as I have stated before.. my early 04 had the short "T" pipe.. as in Dave B's original photo on post #1... the dealer them installed the 04 Gx version of the HR Y-pipe as a replacement for the T-pipe... as if the 03 and early 04's had the short pipe, then on the 04.5's, got the HR clone (no hockey puck hardware).. which is what I have installed since last September. A DEFINITE difference between the two from a sound and performance perspective. It may not be from an HR Z.. but it STILL rocks the house with the same kind of responsiveness and growl!!

my previous post has a picture of the pipe I have.. and it works.. so if ya have one.. KEEP IT!

 

the 06 air box mod will fit as a direct bolt on replacement, the MAF tube screws on to the air box cover you would be replacing without any problems... same case.. different stack with the case.

 

This sounds very good! Kudos on an inexpensive yet very high quality exhaust system. Have you dynoed the car yet?

I wonder what it would sound like with HFCs

not sure yet but I think you should go for it!

What CB are you running? If you're still on the stock exhaust, then I'd try to find a sound clip of an HR 350z with the Megan Racing V2 TPs and bam...there you go!

 

I have the Megan Racing V2 test pipes and it is rattling like a ****. It was fine with the stock cats though. I'll test the test pipes with the stock y-pipe and see if the rattling goes away. I think it might be due to the fact that the HR y-pipe has longer "arms" and longer flex pipes which allows it to flex more. This plus the fact that the test pipes don't use the stock support bracket makes it move around more. It's basically cats all the way to the end of the exhaust without any support.

Update: I forgot to mention that as it sits, the exhaust pipe is about 0.25-0.33" away from hitting the kframe. So once the car gets moving, I'm sure that the exhaust is flexing up and down and hitting against the kframe.

 

Do you have a pic?

 

I measured the downtubes and the outlet size of the midpipe junction on the G37 Y pipe today. These are the two main differences between the DE Y pipe and the DaveB referenced in his first post of this thread.

The G37 downtubes (with the flex section included) measured roughly 13", just like the 350z.

The midpipe junction measured 2.5", just like the 350z.


I will most likely be installing the G37 Y pipe on my car this weekend. If anyone would like me to make any other measurements or take additional pictures, feel free to post here and let me know. At this time I agree with the others who have said that the differences between the G37 and 350z HR Y pipes are purely cosmetic. I guess the only way to find out for sure would be to test out both Y pipes on the same car. I'll volunteer if someone would like to send me a Z HR Y pipe .

 

downtube inside diameter would be nice.

 

Looks like 1.75"

 

I just finished installing the G37 HR Y pipe on my sedan.

Like others have said, it seems to shift a lot smoother now and the initial take off lag seems to be gone. It has a bit of a deeper tone but nothing dramatic. I'll post more impressions after I put a few more miles on it. Seems to be money well spent.

 

The inlet pipes on my HR 350z y-pipe were just a crack under 2" ID, just like the DEy-pipe, The outlet was the same as well at approximaltey 2.5" ID.

 

The downtube (inlet) pipes the the G37 Y pipe are definetely smaller than the stock DE Y pipe. I have been wondering why the engineers would have used this design on a car with a larger 3.7L engine and 330hp stock, unless it was in some way superior.

It looks as though they used the same Y pipe on the 370z:







Looks identical to the G37 Y pipe doesn't it?