I mis-spoke. I had assumed the newer Maximas transitioned to the higher displacement, compression, bore/stroke VVEL-based VQ37VHR a few years back; That doesn't appear to be the case. They would compare more favorably with the 1st Gen G Sedan. It doesn't seem that the traverse mounted nature of the engine in a FWD car would make a huge difference in way the exhaust system would respond to modifications. Based on my experience with much larger displacement engines years back, it seems that anything over 2.25/60mm would be overkill for a naturally aspirated 225 cubic inch V-6.

I agree that this one would be worth trying out.

 

Upon closer inspection it looks like it has an H-Pipe, so not a true dual...still interesting looking exhaust though.

 

I think you're absolutely right. Good catch. If that connecting piece were just structural, it wouldn't be tubular; it would be flat like the welded piece connecting the two resonators.

Although I'm still waiting for Brad to explain why it's best not to cross the streams... on the assumption he didn't get my joke. Personally, I thought it was obvious. Let's see.

 

 

It's been so long since I saw Ghostbusters that I did miss the connection, lol.
But yeah, having an H pipe is an improvement upon a separate dual and an X pipe an even better transition as it combines the flow but doesn't disrupt it as much.
Having that H connector (which I didn't notice until PGv36 pointed it out) is a nice addition and should smooth things out quite a bit. This does look like a pretty well designed setup, and as long as the piping isn't paper thin and the welds are solid this does seem to be a decent option on a tighter budget.

 

FI uses an X-Pipe design, and they do it by cutting holes into the bend, and welding them together:



Researching X-pipes, H-pipes, and straight-dual exhausts because of this thread has been pretty fascinating for me.

The take-away is that true-dual is no bueno.

 

FI does it well, that gentle merging of the X w/ easy mandrel bends should be the best way to incorporate that scavenging effect and noise cancellation.

 

This is the old mid-pipe that Fast Intentions first used for their g37 catback. I have experience with both that and the new x-pipe. The new x-pipe definitely flows better, especially from 3k rpm and up. The x-pipe also sounds throatier and has a cool hiss sound.

 

If I'm not mistaken, that Magnaflow muffler in the first gen FI exhaust was an X-Pipe internally as well. I think it's perforated, so some purists balked at whether or not it was a true X-Pipe, but it is an X-pipe design.

My question is this....if X-Pipe is superior in every way, why don't OEMs use this design? seriously, the cost of creating an X-Pipe as opposed to the traditional Y-pipe would be minimal at the OEM level. What trade-off made them choose the more traditional Y-Pipe?

Since most good mods come from countering trade-offs made by the OEM, I think it's important to understand why certain paths were taken.

For example, the tapering of the sedan exhaust from 60mm to 50mm after the mid-pipe was probably made to minimize resonance and noise in the interior. The massive mufflers on the sedan were probably chosen for the same reason. Recall on the first gen sedan, they used a small muffler that flowed well, but was criticized for being too loud and 'harsh' by US standards, so they introduced that massive mid-pipe to minimize the noise. Replacing that mid-pipe with an after-market resonator made a huge difference in tone.

 

While we are "thinking outside the box"....anyone consider the Infiniti Sport Muffler Kit for the G37?

2014 Infiniti Q50 Forum - View Single Post - Infiniti Sport Muffler Kit for Q50

Minus the remove of a few extra shrouds/covers on our cars, the underside should be identical right? The mid-pipe looks the same as the one on our car.

 

Nix the Q50 Sport Exhaust idea. Our trunk pan seems to be deeper than the Q, preventing the mufflers from being routed at the same angle.

 

So who is going to be the first to pull the trigger on this? I want sound clips / impressions!

 

If I was in the market for an exhaust, I would do it. But I'm happy with my Top Speed.

I'm really impressed by this, a Y-pipe included and a H-pipe setup for <$600? I'm thinking all that cost cutting will show up somewhere in fitment or weld quality but I'd love to be pleasantly surprised by someone who purchases this.

 

Found a clip of it on a coupe (sound clip begins around 2:20)

 

subscribing....