350Z HR Y-pipe installed on a 2003 G35

[DaveB]

When the 2007 350Z came out with the VQ35HR motor and I saw pictures of the exhaust I took interest in the new Y-pipe. The layout of the y-pipe was entirely different than the Y-pipe that comes on the 2003-2006 G35s (VQ35DE/Revup). What really caught my attention was the longer down tubes and two rubber pucks mounted to the inside portions of the pipe. In exhaust theory, usually the longer the downtube off the header/manifold, the better the torque and powerband. I don't know if this was Nissan was going after, but obviously they saw some sort of performance benefit by substantially revising y-pipe. The rubber pucks were clearly installed to reduce NVH from the exhaust. After discussions with Godmans on this site, it turns out this revised Y-pipe fits because he's had it installed on his 1st gen G35 for a while now. I picked a HR y-pipe for $50 shipped and decided to give it a try for the hell of it. Tony with Motordyne has stated he thought the longer downtubes could improve low/midrange power because he's tested numerous Y-pipe downtube configurations when developing his new exhaust systems.

The DE y-pipe downtubes are about 5" long whereas the HR y-pipe downtubes are over 13" long. The exiting pipe at the midpipe junction is a full 2.5" vs the 2.35" for the DE y-pipe. Major power gains!!!!!!!!!1

Here's a shot comparing the two pipes:



I got the pipe installed tonight. There are no clearance issues and the pipe fits like the DE pipe. I drove around for about 5 miles and the car feels good. The car does feel better down low and in the midrange (nothing earth shattering), but I need to give it a week or so because my experience has been that it takes Nissan ECUs some time to adjust. One thing I did notice was reduced NVH under heavy load (low rpm going up hill and WOT). The exhaust tone is slightly deeper too and is slightly more exotic. Keep in mind I do have the 05/06 midpipe on my 03.

[G35_FTMFW]

awesome, hmmm interesting, DYNO time!

[godmans]

glad to see that you like the setup

[5150DS]

Sounds like a great future mod for early sedan owners. Just wondering, you said the stock y pipe is 2.35", while the revised is 2.5". My question is whether the mid pipe on the early sedan is 2.35" or 2.5"? Also, what is the size of the inlet on the revised y pipe compared to the stock y pipe?

[DaveB]

Originally Posted by G35_FTMFW

awesome, hmmm interesting, DYNO time!

Wouldn't be very useful because I have never gotten the car dynoed

[DaveB]

Originally Posted by 5150DS

Sounds like a great future mod for early sedan owners. Just wondering, you said the stock y pipe is 2.35", while the revised is 2.5". My question is whether the mid pipe on the early sedan is 2.35" or 2.5"? Also, what is the size of the inlet on the revised y pipe compared to the stock y pipe?

The midpipe diameter is 2.45". The gasket is 2.5". The downtubes on both y-pipes are 2" ID.

[DaveB]

It's been 2.5 days since installing the new y-pipe and I've put on about 60 miles. The pipe must flow differently because I noticed the 5AT shifted a bit more abruptly and got slightly confused (longer delay) when mashing the throttle. I've noticed the same behavior when I've played around with various intake setups and when I had my Borla TD exhaust. As the miles and time has accumulated, the shift logic has been adjusting back to normal.

With regards to exhaust tone/volume and performance, the exhaust is louder, but not excessively so. The VQ warble is more apparent now and the motor has a deeper WOT growl. The car seems to launch harder as the annoying intial bog seems to have been lessend and motor seems to get over that 3000rpm hump when coming off the line. I can spin my 18s with PZeros easier on the launch, BUT it may just be the cooler temps we've been experiencing here in Kansas City fo the past 3 weeks (70s/low 80s). On Saturday night, with the wife and kid in the car, I had to make a pass around a slow moving truck and the G downshifted into 2nd at 40mph, going up hill, and the car took off with what appeared to be more authority. Even the wife noticed it and said "was that the part you added to the car" followed by the backseat 3 y/o driver giggling while saying "wow, daddy went fast". This percieved added performance could be all in my head though. The good news is there seems to be no downside to the pipe other than some additional volume.

I plan to add some videos of the setup this week.

[DrewQ1]

So how would this work on a 04 Coupe with Test pipes....I am interested in it, but would it fit?
Also, where did you order it from?

[DaveB]

Originally Posted by DrewQ1

So how would this work on a 04 Coupe with Test pipes....I am interested in it, but would it fit?
Also, where did you order it from?

This pipe will bolt on to any 1st gen G35 or 350Z. I got mine from a Z owner on my350z.com.

[gunluvS14]

interesting discovery, good job

[willthethrill]

interesting, it even just looks more fluid than the original de y-pipe

[SFLG35]

might be a dumb question, but what do you mean by NVH?
looks good though

[sloppymax]

Originally Posted by SFLG35

might be a dumb question, but what do you mean by NVH?
looks good though

i believe it is short for noise, vibration and harshness.

[SFLG35]

Originally Posted by sloppymax

i believe it is short for noise, vibration and harshness.

cool cool thanks
yeh i was think noise vibration harmonics, but wasnt sure.

[Rodrigo]

good find Dave!