I just installed my WSP Y pipe this weekend (took about 2 hours, the 02 sensors where my biggest hang up, and I ended up taking some of the protective covering off the bottom of the car to get at them easier, other than that pretty smooth sailing, just make sure you have flex attachments, I think they where invented just for japanese cars LOL.) The only other exhaust modification I have is a Tesudo Muffler. Anyway when I started up the car it sounded perfect, I am very conservative about sound but the difference between just the muffler and the muffler plus the Y pipe was just a slightly deeper note, and little more aggresive at WOT. However, when ever I would really get on the throttle I would hear some rattling/buzzing underneath my shifter (it only occured for about a second.) I thought Oh no the dreaded bees in the can sound that everyones been talking about. It didn't do it when I would rev it up so I knew it had to be when it was under heavy load. I jacked it up on a floor jack and had a friend power brake it in first and give it a little gas (be carefull if you try this.) When the car is put under load the Y pipe would move pretty aggresivly (thank god for the flex section) and it was actually hitting the old mounting bracket from the stock Y pipe. I bent it out of the way and that helped a lot, but I was finally able to solve the problem by cutting away a very small section of the stock bracket. This problem is because the WSP Y pipe is straighter than other Y pipes that I saw like Stillen that have a slight bend by the flex section, not that I am complaining at all about a straighter pipe. With my Y-pipe and Tesudo muffler my Maxima's sound is very comparible to a 3000gt. Just a deep throaty growl that is constant, I was very impressed with the sound, seeing as I was very nervous about it sounding like a Honda with a straight pipe. In fact a fireman from next door came over while I was doing the swap. After he heard it, and after I talked to him about the possiblities of the max, he called his wife and told her he was starting on a new project car, her Maxima

As for butt dyno's I couldn't tell a real difference, this is why I am skeptical of others claims about the dramatic results of different intakes, I beleive this is the placebo effect.

However when I raced one of my friends that I had before the Y pipe the extra power was there. My friend has a 3.2 CL with comptech this and that, and I can tell you from a couple of runs we both could see that my car was performing better, the most dramatic at the last of the RPM range, as well as the bottom (ie: just before shifts, and right after)

The next night I went out a yellow Focus was driving next to me wanting to race. We punched it from about 50 and I steadily pulled on him. At the next light his mouth was wide open, and he was looking my car up and down like it had spray paint all over it. He asked what I had, and I said just a down pipe, to which he replied it's fast. Being a focus I thought I would pull harder on him, and I didn't understand why he was gawking at my car like it was a Ferrari. At the light we went from a punch and his back bumper was at my front bumper till 40, then I started pulling hard (I love the VQ.) We did this twice with the same result, I just couldn't get a launch that would beat him before 40. I asked him what he had and he said intake exhaust and 75 shot of nitrous. Thats when I realized why he was so disappointed about losing to an almost stock car, I Love it when people look at the Max like it's a camry, it almost makes me happy that the majority of people don't know the potential of these cars.

The Y pipe took about a month to get hear but was well worth the wait, I hope this post helps anyone that may have the same vibration when the car is put under heavy load, my car is a fourth gen by the way

 

Nice little writeup about your experience. Pretty smart of you to test the engine like that, but be careful next time cuz the car could fall on you.

 

did you have a problem with the o2 sensor? what year is your car? did you get the ss y-pipe? if so, i will be waiting about a month as well. damnit

 

Unless they sell another pipe that I don't know about it should be the SS, the only other pipe that was more expensive was the one with TIG welds, but it was said this gives no performance advantage. Yes the o2 sensors are tuff to get off and the clip by the oil cap is a pain. Just get the instructions off of Maxima driver.com, I didn't go in the exact order, (I disconected the 02 sensors from under the engine before I jacked it up) but it gives you a good idea of what to expect, and make sure you have flex attachments for your ratchet, or I would take it to a muffler shop. Try not to look everyday in the mail because it will never be there, but once it is the wait will be worth it, keep me posted on this thread about how the install and sound is.

 

also remember that it does take several days for ur ecu to relearn the new airflow.... in other words, u'll feel it more as the days go by