I've searched and searched, but out of 40 threads I looked through, I could only find one little anecdotal claim from a poster about 350Z y-pipes giving 3-5WHP. Is there any proof to this? I didn't find a single dyno sheet or anything. When I had my 5th gen Maxima, our OEM Y-pipes were really restrictive and aftermarket gave us 10-13WHP on the dyno, 15-18WHP when with an intake and tuned.

What're the gains like with the top-brand y-pipe for Zs?

 

stillen Y-pipe claims a 7hp gain i read.

 

Anyone else?

 

I doubt anyone spent $300 to dyno a $150 part on its own, but that's just my opinion.

 

i got a used megan racing y pipe for $75. got 5whp out of it lol.

 

The Y pipe needs to be used in conjunction with something else...

You will get a gain, but it will be very marginal at best.
I would get a good catback, and you will be much better off
Just my .02

 

I have a hard time justifying $1000 on a new exhaust, especially since their gains always seem to be very minimal. Correct me if I'm wrong, though.

On top of that, I hate how most of them sound. Deafening when you're revving past 3000RPM - Borla and some other exhaust certainly were.

 

Anyone have any theories on how this would affect the rear mounted turbo setup in conjunction with test pipes? What exactly does an aftermarket y pipe do differently to give it gains anyway?

 

flow better just like any other exhaust mod im assuming. If you look at the stock y pipe with the shield off it is pretty restrictive in its own.

 

well i dont personally know if it gives u HP but I could imagine it does if you look and see how restrictive the stock y-pipe is. Hope this helped

 

If you want a mellow sounding exhaust go with stillen

 

i have stillen, it's not THAT mellow. however, compared to others it is.

a lot of people have told me my exhaust was LOUD. i thought that was a little weird. anyhow, didn't dyno after installed, but the difference was very noticeable. so i'm happy.

 

I've never been able to find a legit dyno either. All I've found is butt dynos, "it looks restricitve therefore it must restrictive", "it should add 5hp or so".

One thing to keep in mind about Y-pipes on 95-01 Maximas is that the y-pipes also removed the precats which posed the largest restriction. On the G/Z, the precats and cats are all one device and are located upstream of the y-pipe. Replacing the y-pipe on a G/Z only adds some prettier pipes and I don't think the OEM is that restrictive. It looks ugly though.

Something I've been thinking about for a while is to develop a y-pipe that removes the precats/cats and then uses a large 2.7" cat just south of y-pipe junction for emissions purposes and to keep the exhaust velocity up (ie I think test pipes hurt exhaust velocity in the low to midrange rpms). The Y-pipe would have the OEM-style flex sections also to reduce NVH and o2 bungs to keep the CELs off. The setup would be exactly like what is found on a 95/01 Maxima with an aftermarket y-pipe. I don't know what the numbers would be like though.

 

One of my first mods to my 03 was a Y and mid pipes from Japtrix. That been the only change, I went to a dyno and posted some of the best numbers there compared to mostly stock 350Zs from the same year, around 10hp over. If my memory serves, most of the cars were doing low to mid 220s at the wheels and mine came in at 23x somewhere... It has been a while and, of course, I don't think I have the dynos (I will check).

They had done a lot of testing and found very little difference on changing the stock muffler, just basically sound, so they went with Y and mid pipe. If you look at the stock pipe is more of an I pipe, with extreme almost 90 degree bends, the Y goes from the stock cats to the connector on the mid pipe straight.

After that, I went with headers, HF cats, etc... so can't tell you know how much is from the Y and mid vs the rest. I have always been happy with the sound and performance I got from the minimal expense.

I noticed two things back then that stick in my mind : When I drove the car and didn't pay attention to the speed, after I got to 6th and crusing, I would find myself at around 85mph. But after the Y/mid pipes, I would constantly find myself at around 92mph or so. But that could be because of the sound I guess.

The other thing is that the revs would not drop as fast between gear changes. Again, thats just driver observation.

For the last 4 years I have always felt it was the right results for the money, I still have them on, and going to true duals (the only other choice I considered) would be a lot of $$$ for minimal gains.

If I find the dynos I will post. No, I don't have a baseline before the pipes, so thats why I compared my results to other stock 350Zs at the dyno.

Edit : see how memory fails? This was writen back them by a fellow club member : "The best money to power ratio was a 350Z with only Japtrix Y-pipe, Japtrix Mid-pipe and grounding kit, he had 245!" that was (is) my car. And I don't think the grounding kit helped that much.

 

Found more info on them (the rest is copy/paste, not mine) :

The Y-pipe is 2 1/2" on each side coming together to a 3" section and the straight mid pipe is 3" with a resonator/silencer. Both are made of Stainless Steel and mandrel bent.

Below is the Dyno sheet with the curves with the stock pipes and the Japtrix straight pipe only followed by the dyno with the Japtrix y-pipe and Japtrix straight pipe together, all runs where at the same place with a Dynojet. The numbers in summary are:

The baseline dyno was 237.2 HP and 231.9 TQ
Japtrix Straight only 242.4 HP & 239.2 TQ increase = 5.2 HP & 7.3 TQ
Japtrix Y-pipe and straight 248.2 HP & 243.2 TQ increase = 11 HP & 11.3

 

where did you get that nice little piece from?!?!

 

Later, when I had the headers (TopSpeed) and HF cats (Kinetix) installed, I had all the pieces coated to eliminate heat transfer. Notice that the path the Y pipe takes puts heat right under the foot wells. My passengers noticed it.

The Y and Mid pipe are from Japtrix. Google Japtrix and "Y Pipe" and several references come up.

 

A few pulls for $40 x2 = 80 for baselines and afer Ypipe....who pays $300 for dyno time?

My feeling is why buy a Y pipe when you the X02 full dual cat back shows significant gains for 550 or so.....

 

A local shop around here charges 35 for the hookup + 1 pull, and 25 for every consecutive pull.... a before and after and you're only looking at $70.... two before and after... youre looking at $120.....do the math... thats a far cry from $300.... not to mention... the part isn't $150 unless you get some cheap ebay knockoff POS... even a megan Y-pipe is $200 and that's bottom shelf quality.... sarcasm doesn't work very well unless you get your facts straight....