2005 G35c 6MT (before & after HR Y-pipe dyno)

[Reidonly]

Here is my chart from today overlayed onto my chart from last year. The only difference is the VQ35HR Y-pipe I added. The weather was almost identical to last time, and you can see the runs are within about 1hp until about 4000 rpm, where the Y-pipe bumps the power up a solid 6-7hp over the rest of the chart. I ended up putting down 250whp/223tq with a Popcharger intake, Ztube, and the HR Y-pipe.

Here are the weather conditions from last year and this year for comparison - pretty close.

06/29/08 12:15pm -- 84.9º, 29.66 in-Hg, 41% humidity -- 245whp/219tq
07/26/09 11:13am -- 86.3º, 29.58 in-Hg, 33% humidity -- 250whp/223tq

[The next best]

good post,
what year hr pipe was this?

[Blue Dream]

Great numbers for your limited mods. Especially your 1/4 mile time.

[Reidonly]

Thanks. Those times were actually bone stock before any mods, about a week or so after I bought the car.

The y-pipe is from a 2008 Nismo Z a buddy of mine has. He put headers and full exhaust on it. I'm still trying to also get the OEM headers from him too hehe. :-)

[Reidonly]

Here are some HD videos of two of my pulls (thanks to TNTraimair on LS1tech!)...

http://www.youtube.com/watch?v=dSOHcsdrO5k

http://www.youtube.com/watch?v=5Lp6yXO8o-A

[thescreensavers]

Originally Posted by Reidonly

Here are some HD videos of two of my pulls (thanks to TNTraimair on LS1tech!)...

http://www.youtube.com/watch?v=dSOHcsdrO5k

http://www.youtube.com/watch?v=5Lp6yXO8o-A

second one is with the HR-Y Pipe right? Holy crap it sounds beast!

[Reidonly]

Originally Posted by thescreensavers

second one is with the HR-Y Pipe right? Holy crap it sounds beast!

No, both videos are with the HR y-pipe. They are from the same day just different angles. But yeah I love the added growl!

This video is from last year's dyno with stock y-pipe for comparison:
http://www.youtube.com/watch?v=PcxvoaRpnZI

[DaveB]

Sweet! Thanks for posting.

[Reidonly]

Sure thing. I hadn't seen anyone else post up any before and after comparisons, so here it is lol. I also dyno'd at the same place both times btw.

[DaveB]

Originally Posted by Reidonly

Sure thing. I hadn't seen anyone else post up any before and after comparisons, so here it is lol. I also dyno'd at the same place both times btw.

The ideal scenario is to dyno within the same day, but how often does that really happen nor is feasible. You've stuck to the same dyno, only did one mod, and the conditions are basically the same therefore you've removed a lot of the dyno bias. It's clear to me that there is defintely a gain because the shape of the curves are different and start to elevate at 4500rpms and continue to gain all the way to fuel cut. It's actually a pretty substanial gain too because it's right in the heart of the powerband and is sustained the whole way. I had thought I felt the car pulled harder in the mid and upper rpms, but butt dynos are always misleading.

[CandlestickPark]

Sweet, thanks for sharing these results!

[G15]

how much is the HR Y-pipe you have? (im too lazy to google)

Holy crap just watched the vids and damn, that thing has the sexiest growl, that keeps the integrity of the g35 growl and adds to it.

[Reidonly]

Originally Posted by DaveB

The ideal scenario is to dyno within the same day, but how often does that really happen nor is feasible. You've stuck to the same dyno, only did one mod, and the conditions are basically the same therefore you've removed a lot of the dyno bias. It's clear to me that there is defintely a gain because the shape of the curves are different and start to elevate at 4500rpms and continue to gain all the way to fuel cut. It's actually a pretty substanial gain too because it's right in the heart of the powerband and is sustained the whole way. I had thought I felt the car pulled harder in the mid and upper rpms, but butt dynos are always misleading.

Yeah, the conditions are about as close as you are going to get a year later lol. Not to mention I always go by SAE numbers, which are corrected for conditions anyway. Also, you can see how both charts are within maybe 1hp of each other before 4500, then it starts to ramp up, so I think that also shows how close the conditions were.

Most people were saying they felt the HR pipe improved the low-mid range on the butt dyno, but this definitely shows otherwise. I am supposed to get a stock DE lower plenum from a friend of mine, then I want to get a 5/16" spacer and see how far I get on the free/cheap modding path lol. I'm still waiting to see if I am going to be able to get the OEM headers from my buddy that gave me the y-pipe.

Originally Posted by G15

how much is the HR Y-pipe you have? (im too lazy to google)

Holy crap just watched the vids and damn, that thing has the sexiest growl, that keeps the integrity of the g35 growl and adds to it.

I have no idea what MSRP is from Nissan, but I would just look for a used one on here or my350z. If you are willing to pay full price for a new one, you may as well just go ahead and get an aftermarket one at that point.

When I was first reading the long thread about the HR pipe, people were selling them used for about $100-150. I got mine for free from a friend who put headers and full exhaust on his '08 Nismo Z. Like I said above, I am hoping to get his stock headers too and see what difference that makes.

I love the improvement in the tone of the exhaust. Its slightly louder (not much), but it definitely has a much more noticeable deeper growl at WOT now.

[DaveB]

The only aftermarket y-pipe I'd recommend is the MD XYZ pipe. The other aftermarket y-pipes haven't had the R&D and I have yet to see one actually make power. Many people report a loss of power/throttle response below 4500rpms with them. The HR y-pipe and XYZ pipe have a different design than most every other aftermarket pipe out there. It's probably why they show gains and improved driveability. However, the MD XYZ pipe does loose a bit of power below 2800rpms.

[Black Acc]

I just picked up a HR Y pipe from a 08 350z. Going to install probably this weekend.

Not to burst anyone's bubble, but couldn't it be possible you gained some of the HP from the popcharger/ztube intake you installed?

As you mentioned you did the dyno when you first got your car with no mods.

Just curious..