Just add the coupe mid pipe and rear HKS. It's a very nice combo as far as tone goes. I love the sound of my sedan. Really sounds more like a coupe, really.

 

I thought about a Y pipe, but I believe (correct me if I'm wrong) the exit on most aftermarket Y pipes are 3 inch, the mid pipe on our cars is 2.5 inch and the HS exhaust is 2.5 inch.

 

You are correct. And what can happen (happened to me) is you may get a rasp which is basically the exhaust coming out of the 3" section is squeezing back into the 2.5" section and producing this noise. In the end, I gave away my Y cause I just couldnt take the rasp anymore.

A way around this would be to have it custom welded. I have yet to find a Y that comes with a 2.5" opening.

 

I wonder if this is the only real way to get any type of gains? ie...3" outlet. I would imagine it would hurt the low end.

But in regards to your idea, another would be to keep the Y's 3" outlet. But fabricate a flanged adaptor using a 3" --> 2.5" reducer cone. OF course you when would have to chop up your stock Y. Hmmm how much shorter is the Z mid pipe again? If it's shorter on the Y to mid connection................

 

Yep, that would work too. As long as the 3" goes into a 3" flared end it can reduce back to a 2.5" pipe with no issues (rasp).

 

I'm sure they sell reducers. BUT I'm not sure it would reduce the noise. But it would sure smooth out the flow vs having to hit a straight edge and move around it.

I'd flange the 3" end, cut off the 2.5" flange, cut it to length and butt weld it directly.

 

Agreed. Thats more or less what I was trying to say in my other post. Custom weld. No need to rely on a gasket that way.

 

OEM Y-pipes for all years G35 (sedan and coupe) and 350Z are all the same.

 

The 05 & 06 Coupe & Sedan Y-pipe has a different part number than the 03 & 04.

 

Wow guys gone for a day and a lot gets said there are a lot of real good ideas being thrown around. Some one asked what tranny I have it’s a 5at. well if you guys have something that you would like to try let me know im willing to try what ever worse case scenario if its raspy ill add a glass pack and that should reduce the rasp what do you guys think

 

Different part numbers are fairly meaningless because Nissan and most every other company are constantly changing parts numbers for like parts. I've held an 05 350Z y-pipe and it looked exactly like my 03's other than a slightly different heat shield design on the forward part of the y-pipe.

 

Well, I stand corrected and much thanks for the link. I do however this the 26whp/12wtq gain from TP and a piggyback is quite uncommon, the other link of the TP gains do look legit. I did some more searching on the 350Z site and it seems like most people accept 5-7whp/wtq for the TP. Many say not waste your time with the aftermarket cats though because most people have only seen 2-3whp gains.

Didn't you only see a very marginal gain with your aftermarket cats (Crawford and someone elses)?

It's my understanding that the stock cat converter setup is a precat with the main cat butted up to, hence that relatively long and heavy setup. On the 95-01 Maximas, the y-pipe had two forward precats aft of the manifolds and then the main cat under shifter area. The aftermarket y-pipes simply removed the precats, but kept the main cat. The aftermarket y-pipes were good for a solid 10-12whp/12wtq. I've always wondered about adding quality TPs and then fabbing up larger 2.5" cat near where the y-pipe connects to the midpipe. Having the cat further downstream would aid in reducing the initial restriction off the manifolds plus the car would be emissions legal once the motor is warmed up. The smell and rasp wouldn't be a problem either. I may have to get in touch with my boys at Warpspeed Performance (makers of exhaust components for Maximas/Altimas, SUVs/Trucks, Jeeps, etc) and see what they can come up with. The owner has a newer 350Z. He could probably fab up something real quick plus they use quality flex sections in thier y-pipes which is something most Z/G aftermarket companies fail to use.....and need to.

 

I've held an 05 350Z y-pipe and it looked exactly like my 03's other than a slightly different heat shield design on the forward part of the y-pipe

It's been proclaimed! The clueless one has held and looked so there's no need to remove the heat shields, do a side-by-side comparsion, take measurements or even do an air flow test.

 

There is no chin behind Chuck Norris’ beard. There is only another fist.