The stock Y pipe is a piece of work (sarcasm) . . . I originally changed the stock to:

Kinetix Test Pipes (since I'm turboed), Gruppe S Y Pipe, and RSR Exhaust . . . removed them tonight for: Espelir GT500 True Duals (BEAUTIFUL). The True duals only keep the test pipes. I love the setup--a must have for anyone that doesn't want to be loud & FI. Even on NA its not as aggressive. All in all, it lines up perfect, eliminates the major bends, and really opens up the system . . . while sounding like an exotic

Espelir GT 500 True Dual on the Left, Previous Y Pipe & RSR on the right.

 

my .02: if i had to do it over again, i would have bot used parts to save money. i wish someone had recommended this to me early on.

 

That's definitely a good route . . .

 

Im selling my JIC y-pipe, PM me if you are interested.

https://my350z.com/forum/showthread.php?t=121539

Brian

 

You get weight reduction to. That stock muffler weighs so much. I dropped 18 lbs off my car when changing the OEM midpipe/muffler out with the Pro-1 Exhaust. And the Pro-1 Exhaust isn't light because it is all 3" SS Piping, imagine if I had gone with some Titanium single tip.

 

I've been trying out a few different combos of catback system. I dynoed all of them. They are all within 10 hp of each other.
I've tested:
Completely stock
Stock y-pipe + single outlet Ti JIC exahaust
JIC y-pipe + single outlet Ti JIC exahaust
Top secret Ti y-pipe + single outlet TI JIC exahaust
JIC y-pipe + un resonated Straight pipe

I've decided to go with the lightest option since the HP seems to be for all intents and purposes exactly the same. Currently my exhaust from the cat back weighs under 20 lbs. Its a significant savings of around 50lbs over stock.

Exhaust works in a way the unclogging it close to the engine is going to produce more HP than unclogging it further down the line. If you start with headers that is going to be your biggest gain, replacing cat pipe second and so on.