im doing a turbo installation on my X next week and i was wondering if anyone knows of any companies that offer a aftermarket exhaust that is 3 inch diameter or 70-80mm? i have everything that i need except this part.:grimmig-big:

You will probably have to go custom on that. Your local muffler shop should be able to do that with no problem.

Let us know how it works (include pics).

i started last night on the install since the wifey was watching saops. i will post up some pics ASAP.:wink-big:

I recently installed a K+N air filter and a Magnaflow cat back exhauxt on my 05 X. If you are looking to improve gas mileage forget it. I have noticed no change at all. However it was money well spent the X is much more responsive and it sounds cool. Check your crossover pipe - coming from the header on the driver side to about half way over you will notice it is a 2 piece pipe with a clamp. I had an exhaust leak at that clamp. I had the shop remove the clamp and weld it.

Mud man, is the Magnaflow loud? How about cost?

The cost was $450 - stainless steel pipes, sst magnaflow muffler and polished sst tip.
The muffler is louder on accelleration - if you are talking on a cell phone the sound will make it difficult to hear the other person - when you let off or are at cruising speed it is only slightly more noticeable than stock. It has a nice rumble to it. If you feel that it is to loud you can put a resanator on it. I dont think its necessary. I have a Mustang GT that I put the magna flow flowpacks on with an x-pipe. The X is much quieter than the Mustang. I would definetly put the same exhaust on the X again. I would probably put resonators on the Mustang.

Will you please post pics of the X exhuast.

Is the $450 including installation? Also, I am thinking about just doing the magnaflow muffler. How much different will that sound than the whole cat back system? You said it has a nice rumble, but is it ricey sounding at all? Thanks

The $450 did included installation. I would definetly do a cat back system. The pipe they uses is considerably larger than stock. It does not sound ricey. However it does not sound like a v8 muscle car. I will try and post pictures soon.

I have the Magnaflow SUV muffler and 2.5" pipes from the crossover outwards, with a resonator downstream of the cross over...mostly to make room for my OBA tank.

It sounds a bit deeper and richer than OEM, no rice...just nice.

:D

I can't imagine needing 3" pipe for an X...hell, the 2.5" isn't restrictive at all, the OEM 2" was a smidgen restrictive....but a 3" is like 10x the flow capacity...maybe if I had 350 hp or something.

:D

I have actually been thinking of putting some kind of duel exhaust on my X... why couldn't a foriegn SUV sound a little beefy.... do you guys know of any one who has done this to an X before?

Here's a site with some sound clips of the Gibson exhaust to give you an idea:

http://gibsonexhaust.com/sounds/

Scroll down to Nissan

I have actually been thinking of putting some kind of duel exhaust on my X... why couldn't a foriegn SUV sound a little beefy.... do you guys know of any one who has done this to an X before?

Gene from NEXterra has dual exhaust on his. It's pretty loud, but has a nice low note.

The thing is though, to get a lower note you need a bigger diameter pipe. The larger the diameter pipe, the more power you loose on the low end.
Bigger pipes just allow you to produce more top end power with other add ons like FI, which you don't really care about on an XTerra IMO.

Optimal exhaust pipe diameter varies with engine displacement, horsepower and whether the engine is normally aspirated or forced induction. Exhaust velocity is directly related to pipe diameter. A general rule is the smaller the pipe, the higher the velocity. High exhaust gas velocity helps scavenge the cylinder, especially at lower RPM. However a pipe that is too small in diameter will have high exhaust gas velocity but restrict air flow, whereas a pipe that is too large will have a lower exhaust gas velocity but have high air flow. The optimal pipe diameter is a size that facilitates both high exhaust gas velocity as well as high air flow.
:)

2.5" diameter, single exhaust, from the cross over, out.

:D

Did the math already.

:D

Also found dual exhaust in the case of the X is not going to be an improvement afterwards, as 2.5" is more than enough capacity, and the crossover location relative to the gas tank, drive shaft, etc...negates a straight run anyway.

By the time you wind around on the way out, you gained nothing as far as freer flow...and a single 2.5" exhaust was not a limiting factor anyway.

I swapped in a SS Magnaflow SUV muffler and resonator along with SS 2.5" pipes.

Its louder by a tad, but mostly deeper and richer. Inside the truck, its only really noticeable with the windows down, windows up, barely a difference. By standers on the trail have taken notice of the deeper richer sound, and asked if I'd suped up/swapped in a larger engine, etc.

:D

Its not a cherry bomb...you can still sneak home late, etc...but its a subtle yet enhanced sound, no rice, just nice.

I did it because the OEM muffler was a big honkin waste of space in the huge valley under the driver's side, and I wanted a more compact set of pipes that would allow me to mount a big 4 gal OBA tank there instead.

:D

Workd GREAT!

PS - the trade off between torque and back pressure was one of balance, not so much of absolute limits...so on a modern engine, freer is generally better...but once you hit a point of diminishing return...it does nothing extra for you.

In the old days (Carbs, etc...) the balance issue was more critical.

The scaveging issues and so forth are true, and in a modern engine, related more to the timing of the exhaust pulses than to the pressure differential itself...which is one of the reasons that messing with a modern exhaust's layout is more likely to hurt mpg or performance...

...hence, for the X...staying with the single exhaust after the crossover to maintain the pulse waveforms, with a larger diameter to relieve back pressure, seems to be the best solution.

Replacing the headers altogether, say with SLR's, etc...might provide a bit more oomph, by augmenting the flow out of the engine, coupled with a freer flowing intake, to augment the flow into the engine, etc.

Hope that helps.

:D