Exactly! If there is one pipe from the end of the manifolds, it will always be more efficient to have one pipe out of the back. The name of the game is keeping the heat inside the pipes and more piping will add more wall surface area that will "leak" more heat from the exhaust stream. In a perfect world exhaust pipes would be made of mm thin stainless and all of the sound will be concentrated at the tip of the exhaust outlet ("length tuned" exhaust manifolds strive for this). All that rumbling you hear under your seat is just heat energy that has been wastfully converted into sound energy or vibrations. A good exhaust is one that will be of the correct length to "match" exhaust pulses put out by the engine at a certain target RPM.

 

I believe after Nissan scrapped the idea of dual exhaust setup, it redesigned the spare tire well for the optional full-size spare. The full size is so much bigger in both diameter and width. That's why it is off center.

Or another reason is to balance the weight of the heavy muffler on the left side with the spare tire on the right side.

 

a couple of my friends have modded 2nd gen tl's, the ones rightbefore the new ones...and the stock exhausts are so damn tiny...and they sound like crap too...ill take my single sided exhausts anyday...i used to think why dont they just make it dual but then i realized how small the old tls exhausts were and i thought it would look retarted

 

I like the fact that we don't have the dual pipes. Someone mentioned earlier a bunch of cars that have them and why shouldn't the G sedan. If we had a true dual exhaust setup then hell yeah but I prefer function over form. Now a true dual coming out the sides would be sick.

 

i'm having a similar discussion about this on another thread. it's about a single exhaust setup in a coupe. that's probably the most practical upgrade of an exhaust system, other than a true dual setup. somebody mentioned it being 'ricey'. kind of like putting on a shopping cart spoiler on a fwd car.
daveb and johnnj - i thoroughly agree with you. it's retarded. i think the g coupe and z exhaust is dumb. it looks cool, but has NO function... just like that spoiler we all condemn.

 

OMG, a guy that speaks my language

Keeping heat in the pipe is crucial because hot gases move faster than cooled gases. I always find it funny when people say "the VQ needs backpressure in the exhaust to make torque". NO!!! Backpressure at any level is not ideal. The correct term is exhaust velocity. The VQ, like any other NA engine, needs good exhaust velocity to scavenge the gases out of the combustion chamber. When guys report that the 3" exhaust on their G lost backpressure and ultimately lowend power, I laugh. What they did was hurt exhaust velocity to the point that the exhaust gases started cooling in the larger pipe and created turbulence. This turbulence and lack of exhaust velocity often hurts low to midrange power and is only overcome at the higher rpms when more exhaust is being moved. The OEM exhaust to designed for maximum effiency over a large amount of RPM. The 2.3-2.5" ID of the stock exhaust piping is plenty for this motor in an NA set up. A 3" single pipe catback flows enough air for a 400whp 350 cu. in. LS1.

Another thing people a lot of people don't realize is that stepping the exhaust piping down as it gets closer to the muffler also adds in improving exhaust velocity. People who don't understand this often point to a smaller ID downstream pipe and automatically assumed it's a "restriction". That's not true in some cases. Stepping the exhaust piping down about 1/4" often works out quite well on many NA engines.

 

daveb - that was me that used the 'backpressure explanation'. i'm familiar with these basic concepts. but i figured it was easier to explain to someone using their own language to avoid a much longer response. but thank you for pointing out what actually occurs.

 

I wasn't trying to take a jab at you, personally. Sorry if it appeared that way.

 

no worries. we're on the same page.

 

Can someone repost the pre-production model pics again? Thank you.