Need your thoughts on sound and HP gains please...

 

I have one on my coupe (therefore I obviously have the coupe mid-pipe). I say spend the money elsewhere first. The y-pipe should be one of your last mods that you do. I'd bet that 5bhp is a bit optimistic for a simple pipe swap. Heck, a full Stillen exhaust (true dual) yielded ~7rwhp in the SportZ exhaust shootout and that's not really all that much if you think about it.

7/280 = 2.5% increase

 

I'm actually changing the Mid pipe for the weight and sound so was thinking about the possible synergy of the Y pipe combined with the mid pipes being less restrictive...even if it's about 3 ponys, it adds up with the 2-3 from the mid (maybe) and the 10-20 from the plenum and the 5-10 from the pulley and the .00001 from the 10 wires and the 2-6 from the z-tube and airbox mod.

Hell for a total of 300-450 bucks I think I can get the same gains as a full $1200 Stillen exhaust, shed weight and sound great and not lose sleep about the price. I like the little gains here and there that add up to a major improvement over stock and I need to pay more attention to the back end of the block for a change. Changing the cats is not for me nor is changing the muffler. Doesn't leave much for me to play with and I want to play! There are few mods left for me to do anyway so this may be my last mod BEFORE the chip or piggy back this summer...

 

Also I guess it's safe to say that if the coupe has an aftermarket Y and the stock mid pipe and there are no droning issues, I could expect few adverse sounds or drone from my sedan with a aftermarket Y and the coupe midpipe - right?

 

You'll lose about 5 lbs and I didn't notice any type of change in sound quality or level.

 

I think back a few months when that TD Y pipe GB was going on, only a few ppl actually posted their impressions after they installed it (which weren't all that positive if I recall); not much difference in sound and little or no gains in HP. With that in mind, I opted for just the Coupe midpipe (no aftermarket Y pipe) for $235 + shipping (www.PerformanceNissanParts.com) + installation costs.

After a couple months, I continue to smile every time I start her up...the sound is much better with a deeper exhaust note between 0-2,500 rpm; then my Z tube's sound kicks in of course above 3,500 rpm anyhow. My car sounds a bit more like the G35 Coupe, FX35/45, and 350Z...at least at idle and buzzing around below 2,500 rpms anyhow (no drone). However, I'm sure there's little or no increase in HP (even with a less restrictive Coupe midpipe).

So, I guess the bottom line is...my suggestion is to just get the Coupe midpipe and see if you're satisfied with the sound. If not, you can always add the Y pipe. Personally, I don't think that the HP gains from an aftermarket Y pipe have been proven. Now, if we see a whole bunch of G35 owners coming out saying they dyno'd their cars before & after they installed an aftermarket Y pipe and saw decent gains in HP, then I would be more comfortable with the claims; until then, I think the Y pipe may not be worth the money. If you add the cost of the Y pipe (about $250 or more) + the cost of the Coupe midpipe ($235) + installation charges (at least $100 if you don't DIY), you are in the ballpark of an entire Borla or other cat-back system with proven HP gains. Why not just go for the improved sound of the Coupe midpipe alone for much less $$ or if you really want improved sound and increased HP, then go for a Borla or Stillen cat-back exhaust?. I am very pleased with my exhaust system now as is (with the Coupe midpipe of course ). Just my $0.02.

 

Sounds like the right way to do it...coupe midpipe first. So am i only shedding 5 pounds from changing the midpipe? What the hell is that suitcase for again?

 

I believe the Coupe midpipe is much lighter than the Sedan's stock midpipe (more than 5 lb. less...it's gotta be at least 10 lb. less); yeah, that big suitcase on the stock midpipe is a bit ridiculous! I think you'll be much happier with the sound of the Coupe midpipe/stock Y pipe.

 

Does that suitcase quiet the pipe resonance or something...after dropping the pulley, the stock sways and now the suitcase, my car is going to be WAY lighter than the 05. It already feels so light on it's feet. The Y thing is starting to sound expensive. For 100 buck, the mid sounds like a no brainer...thanks for the comments guys.

 

The oem Y-pipe is a terrible mess that is not friendly to flow or scavaging, Infinti/Nissan is smart to cover the main parts up with heat shielding so you can't see those important parts. Any aftermarket Y-pipe would be a improvement, providing you don't mismatch pipe diameters. Real gains would be most recognized with a new Y-pipe being part of a well thought out set of componants from their to the tail pipe. Making matters even more difficult is the fact that the two Y-pipes that have matching oem pipe diameters where they connect to the oem mid pipe, have issues. Kinetix has fitment issues and is NOT the part they promised in their picture advertising and NFC's web site is dead, I don't know if they are still in business. IMO this means your faced with needing to either increase your mid pipe diameter to match the current crop of aftermarket Y-pipes or to modify the Y-pipe so it smoothly blends from 80mm/76.5mm/70mm to 65mm. Don't want to bother with that, get a TD system or stick with the oem Y-pipe until someone else brings out a Y-pipe ment to match the oem system down stream. Just because a manufacturer say's it will bolt up to the oem system doesn't mean it makes sense or is the right way to make power.

 

Here's my set-up : fujisubo "like" y-pipe(much, much better flow design),
oem midpipe removed(just straight pipe now), oem muffler and stock airbox mod with k&n drop in panel filter...........

Sound: much, much more meaner and it growls from 3.5k till redline....at idle, just a little deeper tone........again like folks have mentioned, hard to describe sound....gotta be there.

HP gains.......most def.......i dynoed 245hp and 243tq on dynopack..however, they say dynopack dynos higher approx 10hp/tq more, so let's say i'm at 235hp and 233tq...i'm still happy though.............my butt dyno says car pulls harder as well...........

btw: oem sedan midpipe is 30lbs!!..(bathroom scale).....straight pipe at most is 10lbs.......lose weight, why not.........

peace.

 

That deeper exhaust note is probably from your new "straight" midpipe; again, the Coupe midpipe provides that, but in the lower rpm range. If you have a Z tube, the "mean" sound from the Z tube would most likely drown out the exhaust sound above 3,500 rpm, unless it's a really loud cat-back like a Stillen, Borla, or something like that.

I am by no means an expert, but my experience and research lead me to switch out the stock midpipe for the Coupe midpipe for a noticeable improvement in sound...it's a decent, med. priced mod. Although theoretically, they're less restrictive and higher flowing, I still question any real HP gains from just an aftermarket Y pipe or Coupe midpipe for that matter. I do love the sound of the Coupe midpipe though!!!! Too bad our G35 Sedans didn't just come std. with the exact same exhaust system as the G35 Coupe, FX35/45, and 350Z...what a shame!

 

i forgot to mention the z-tube as well........and you're correct, the ztube/intake will overpower the exhaust note 3.5k+.........love tunnels!

 

Just a reminder to our viewers: SixFive had the best E.T. at the Atco g/z meet last June 25th. He's only 6' 4 and 1/2" though! 6/5, message me if you wanna meet on the Blue Route and wail on the Evo. I saw you drive, we can switch...steve

 

I just have the coupe mid-pipe, no aftermarket y-pipe. I have grown to appreciate the slight difference in sound over time. Our bathroom scale measured a 25 lb. difference between the two pipes. The mod was well worth the $100 (used) for me.