Any aftermarket y-pipe for 2005 sedan "with proven power gains" by third party with dyno graphs?

 

If there is, you don't need one. Don't want any mod that might put you in danger of getting to that fuel cut-off...

 

If you like, I can enlarge the font, bold it, and post the same thing again.

 

In all seriousness though, so I can't be accused of not contributing, I don't know. I do know however that fuji has a y-pipe, though I don't know about any claimed power gains. I've seen several posts, most notably by DaveB, that questions the effectiveness of after market exhaust replacements, because apparently the stock stuff is extremely high-flo as it is.

 

Any path to fixing a exhaust system's short commings has to be well thought out and informed. While I will not argue that the mufflers on these car's are ok, their are factual point's where the oem system is inferior. The oem cat's have choke point's where their inlet and outlet diameter's are only 1 15/16".
My oem premuffler has it's inlet and outlet pipes sliced off at the body of the premuffler allowing me to measure inlet and outlet pipe diameters, 2 3/16".

The oem Y-pipe is a masterpeace of controlling cost's at the expense of flow.












The problem I see owner's get themselves into is installing a Y-pipe that has a 3" output and mating it to the oem down pipe, which is only 2.5" in diameter. Why would you install a setup that creates a 1/4" wall in the flow path, makes no sense what so ever and defeat's the reason for overcoming the oem Y-pipe's flaw's.

What we will never see are the hp claims that Stillen and Borla claim for their systems on their web sites, they make power just not what they claim.

 

Thanks Gsedan35 awesome post! Ya I took out the premuffler and put in a smaller magnaflow vs the coupe midpipe which most do. I don't need power that much so I don't mess with the oem Cat. Since the OEM y-pipe seems pretty effective that leaves the muffler. I love the sound of the stock muffler since it isn't too loud. Most aftermarket mufflers are pretty obnoxious. Does the stock muffler have a variable exhaust flap inside of it like the Maximas started doing 2001+?

 

Gting-

Yes, the G sedan is a variable capacity muffler. It's the same style used on the former Skyline GT-R and what BMW and Porsche use. Changing out the muffler is worthless on these cars unless you plan to run a serious turbo. The variable capacity muffler improves lowend torque and opens up for improved upper rpm power.

Concerning the Y-pipe, IMO, don't waste your money. What I've learned over the years is that late model OEM exhaust parts are often the best engineered parts out there and that ugly doesn't necessarily mean restrictive. I also haven't seen any reputable proof of the aftermarket y-pipes doing anything other than adding some bling under the car and making the owner $300-500 poorer.

The non-mandrel bends on the y-pipe aren't near as bad as people think they are. Yes, the overall diameter shrinks at the bend, but the calculated volume doesn't go down much at the bend because the bend becomes oval in shape. This isn't your typical MIDAS crimp bend. Most importantly, in NA form the VQ35 can't move enough air for these non-mandrel bends to cause a restriction in power.

In the 11/04 issue of Sport Compact Car (page 140), SCC tested Borla's true dual Z exhaust (which included a new less restrictive y-pipe). On the flow bench, the Borla flowed over 200 cfm more than the stock exhaust. Guess what though? There was no power increase. SCC speculated that the 91 octane and the VQs tendency to operate along the knock threshold was costing the car power and an increase in octane would increase power. I agree power would be improved, not because of the Borla exhaust, but simply because of the higher octane. They already proved that running 100 octane was worth about 8whp/wtq on the Z/G VQ35.

 

Thanks Dave that is what I thought. I guess that leaves headers and UDP. Any proof that a UDP creates any real gains on the G35?

 

I suggest searching. The board knows my opinion on UDPs and most disagree with my views. It will only start a heated debate.

 

Another item up for some debate would be the replacement of the final drive gears.. the 3.9's I think.

 

Well I had a UDP on my 2001 5spd Maxima. I honestly didn't feel any difference. I was hoping there was actual before and after dynos everything else being equal.

 

There is nothing to debate....

The 3.9 gears rock and roll.... Best mod I have done to date (and I have done alot!).

No more "lull in the powerband below 5000 rpm on my '05 6MT sedan.. seamless acceleration curve. Definate increase in response and low end acceleration. from 30-50 mph punch I dropped one full second in acceleration...

 

How does it effect top speed in 5th gear