Stock NISMO vs 370 Stock
 

Perhaps this has been addressed, but I made a few interesting observations. I recently purchased a stock NISMO take off to "enhance" my non-NISMO 370. I had hoped for a slight performance increase (yes, I did realize a slight improvement) and better sound. The performance increase manifested itself in a greater willingness to rev quicker, but I must admit, it could have been wishfull thinking! The sound was deeper, though not by a lot. For grins, I then installed the stock muffler onto the NISMO pipes. First, I noticed that the stock muffler was significantly lighter in weight. The exhaust "note" was more aggressive than the NISMO. Still not what I had hoped for, but a darn sight better than stock and better than with the NISMO muffler.

Can anyone help me understand this? :confused:

I am not sure where you are going with this. Did you mean sound or power? Unless you went to the dyno and performed tests back to back between stock muffler and Nismo muffler then you will not know the difference just by "feel." I have read that the Nismo exhaust is around 5-8 hp range over stock (probably due to H-pipe configuration, true dual setup).

I guess I am wondering if anyone has taken apart the mufflers themselves. I found it surprising that the NISMO muffler would be so much heavier than the stock, unless it is actually quieter to reach a similar decibel range but more efficient due to the "true dual" H pipe setup. One of the complaints I have read on the forum was around the sound output being virtually the same with the NISMO vs the stock. Where I am going with this is in regards to the weight vs performance vs sound. I would have presumed that the NISMO system and more specifically the muffler's weight would have been lighter than stock, not heavier.

There's some info in the private classified section by the person selling the nismo exhaust. He states +5hp over stock exhaust and 9 lbs lighter as well.

I don't think there are any real differences in the muffler section there are a few members here to gutted the stock muffler. The real difference in the Nismo exhaust in how the tubing runs. Stock Z's use the Y pipe design and Nismo's use an H pipe. the differences are so negligible that its hardly worth the investment unless you like to say "I have a Nismo exhaust."

Personally, with so many aftermarket exhausts up for sale new and in the classified, why would you get a Nismo exhaust? Not worth it IMO.

The Nismo H-pipe exhaust makes sense in the Nismo model. It's what characterizes the increase in power (along with ECU tuning)

Like NYBladeZ says, there are so many other exhausts for the Coupe. The Nismo exhaust actually sounds a lot quieter than most other CBE made by other companies. Personally, I like the more subtle sound of the Nismo.

I agree regarding the NISMO vs the other aftermarket brands. Most that I have heard, however, have either raspy and annoying sounds from idle or serious vibrations in the 3500 to 4500 rpm band. I would have loved to purchase the HKS system but I didn't and don't have 2 thousand dollars to spend, so I had hoped that the NISMO would suffice. Right now I have the stock muffler on the NISMO pipes and it seems to be ok. The person who said the NISMO is lighter might be wrong. I know that the NISMO muffler is significantly heavier than the stock 370 muffler. Perhaps the entire system is lighter but the muffler certainly is not. Interesting note, by the way, is that if look into the input ports of the stock muffler you see what appears (I am sure it's not) an open chamber while on the NISMO you see honeycomb steel with packing behind it. Also the NISMO outlets have a packing chamber in them while the stock outlets do not.

Unfortunately the rasp and hiss are characteristics of the z34. I don't know about Jersey but in New York, the first two years after production are a simple inspection and afterwards it is still an obII reader so if I was looking for bang for the buck, a test of test pipes and the stock exhaust would yield more gains.