I've been looking around and I've been trying to find an answer on the forum with no luck - what kind of torque and horsepower gains are there to be had using the ART pipes + XYZ with the cat module? Would it also be necessary to have some sort of premuffler to keep the noise/drone down?

I'm thinking about starting to piece an exhaust together and don't want the smell of test pipes, but want the gain of the ART pipes - which leaves me to place the cat further back in the exhaust. My thought is ART pipes -> XYZ with HFC module -> 3" tubing to premuffler (perhaps optional?) -> 3" tubing to Muffler. Anything wrong with this setup, or any video clips with something similar? I did see the 350z vid earlier in the thread but more data points wouldn't hurt!

 

the smell isent that bad at all. only when you stop at red lights you will get a little wiff but its not that bad.

 

^ Out of all the XYZ configurations, IIRC the HP/TQ gains are from the most to least are: straight pipe>resonator>HFC module.

OP you should probably just PM/call Tony from Motordyne directly (SN: Hydrazine) with your questions. He's pretty much the guru for VQ exhaust setups IMO. But if you browse around my350z there are quite a bit of dyno sheets and vids of different MD setup configurations.


I've got a full MD exhaust on a sedan and the least drone came with the XYZ with a HFC module rather than with a resonator. But drone is subjective to different ears anyways.

 

I don't care so much about the smell, but my car will occasionally be driven by my fiancee and most likely a child will be on its way within the next couple years. I'd rather keep the whole smell thing a non issue. S854 - do you have any videos of your G? Also, you say the drone is the least with the HFC - do you still have a "pre-muffler" after the cat or do you just have a straight pipe running from the HFC to the final muffler?

Thanks!~

 

^ I did the HFC module mostly to not attract any extra attention from local law enforcement more than necessary, although the smell without the HFC wasn't too bad to my nose.

Uh, my full MD exhaust from cat-back is:

MD ART pipes V2.1 (latest version redesigned for 5AT, slight TQ gain)
MD XYZ pipe with HFC module
MD resonated midpipe (there is a straight pipe version which was too loud/drone-y for me)
MD dual VQ sedan muffler


Obviously when you start messing with the XYZ and midpipe configurations the sound will change.

Do you have a sedan? I think the coupe MD exhausts sound different than the sedan MD exhausts. I have a few videos somewhere around here, see if I can upload them later for you.

 

I do have a sedan - '04 5AT. I LOVE the sound of the stock exhaust, but I'd like it a touch louder and just a bit more aggressive sounding. I'm just having a hard time figuring what I want I'd love a bit of HP and TQ gain but don't have a ton of money to spend so I'd like to start piece by piece. I was thinking about a M2 or Megan Y pipe, but I'm concerned that the 2" -> 2.5" mismatch on the cat side and 3" -> 2.4" mismatch on the midpipe side would cause rasp. Is this a reasonable concern? If it is, it seems I'd be better off just doing the standard HR Y + Coupe or Z Midpipe. I'd love suggestions - otherwise I may research it until I'm too old to want a louder exhaust

 

I would think messing around with piping sizes that don't necessarily match up would introduce rasp. I had slight rasp/drone with my previous coupe midpipe/HKS muffler setup. I love the MD full exhaust as opposed to mixing/matching different exhaust components because it's very deep with little to no drone and also Tony designed it to be free-flowing. A custom exhaust would also work well I'd imagine. We've probably taken this off-topic by now but I'd suggest you listen to the sound clips here:

https://g35driver.com/forums/g35-sedan-v35-2003-06/190116-aftermarket-sedan-exhaust-compilation.html



I'll post the vids of the full MD exhaust up there.

In the end, you're only limited by your budget and your ears.

 

Just want to clear a few things up with the naming of MotorDyne's exhaust components since I see them incorrectly called all the time.

There is no such thing as "TDX2", or "TDX V2". For "mid sections" (parts between the XYZ pipe and axleback), there's the Dual, which has 2.5" piping and can utilize the XYZ modules. And then there's the TDX, which is 2.5" piping to the collector, then tapers out to 3", and can't use the XYZ modules. Neither of these has anything to do with the axlebacks, you can use any axleback you want with the Dual or TDX (Shockwave))), Shockwave V2, Gamma, VQ, etc. ).

As for axlebacks (parts after the "mid section"), there's the Shockwave))) (V1), which has no resonators, and the Shockwave V2, which has dual resonators.

In my case, I have the Shockwave V2 axleback with with the TDX mid section (along with ART pipes), or the "Shockwave V2 TDX". It's always confusing when people PM me asking me about information regarding the "Shockwave TDX2", or the "TDX2", because I'm not sure which axleback or mid section they're really talking about. I just assume they're referring to the exhaust I have.

I know it's a little confusing, but hopefully it clears some things up.

 

And as you've updated this thread, i have to chime in with how funny it is to read people talking about test pipes and smells these days.

Cats are not required for engines to run, they're not designed to remove smell, different test pipes do not change any smell people might sense.

A combustion engine makes a certain smell, that's just the way things are, the efficiency of the engine dictates how strong that smell is. The smell is caused by burning fuel, if the engines bad, or usually just american, you'll smell oil in the gasses as well.

The name "Test pipe(s)" seems to be american, another term used is "de-cat" as it describes the removal of the cat, nothing more.


If you can smell the eggy and slightly sweet smell of exhaust, then that doesn't change, it will merely be replaced with a more gas/combustion like smell if you remove the cats and put in a de-cat/test pipe, regardless of the manufacturer.


Usually, removing the cats and placing straight through pipe (test pipes) in their place, results in a power increase and torque increase, however, because of the change in flow, it's typical to lose some power and torque in the low rev range.

It should also be noted that cats also act like a muffler, if you've ever seen inside a cat, you'll know they're usually a honeycomb like design. Removing them yields an increase in sound and sometimes rasp (engine type dependent)

This is where Tony's research really paid off, the Motordyne ART pipes give you the boost in power and torque, just like any other removal of restriction (cats, mufflers etc) but because of the unique design used, he's overcome the typical problems.
The ART pipes are not much louder than a stock system, yet because it's not longer a muffled sound, it becomes very deep and throaty. The same design also maintains way more of the gains from removing stock cats.

It sounds a little too good to be true, but they really are a win win setup. The only case being that they're not cats. The Motordyne XYZ pipe also gives gains over the stock system, it too has a lot of R&D behind it, if you want the cat, use the bolt on high flow cat on the XYZ pipe.


HFC's flow a lot better than stock cats, they don't use the same honeycomb design, but they also don't filter as well. However, most *** cars already run very cleanly and don't need much clean up in the first place.

 

So, if I may, touching on the last two posts by Silencer_0 and MaDMaXX:

What exactly are the possible exhaust configs? I'm getting confused about what goes with what.

Let's say we start with ART pipes... are these the possibilities?:

ART Pipes -> Shockwave 2 -> Done
ART Pipes -> XYZ Pipe w/HFC -> TDX -> Done
ART Pipes -> XYZ Pipe w/HFC -> TDX Mid -> Shockwave 2 Axelback -> Done

Or am I missing something?

 

Hi MP45,

The Shockwave))) exhaust is a True Dual X (TDX) exhaust system, so they are the same thing.

If you are looking for ART pipes and Shockwave))) with a HFC in the system, you can.
HFC's are now available as midpipe modules on the Shockwave))) exhaust.

 

MP45 just to expand on what Tony stated;

You obviously know about the XYZ pipe with the modules. So with ARTs and the XYZ, you could have the following:

ART -> XYZ -> Straight
ART -> XYZ -> Resonator
ART -> XYZ -> HFC

Now the Shockwave system includes the XYZ, but does not use it's modules, however, the Shockwave it's self is modular, so you can have the following:

ART -> Shockwave
ART -> ShockWave with HFC midpipe module.
ART -> Shockwave with Resonated midpipe module.


Hope this helps.

 

^^Very helpful, thanks! So to make sure Im understanding, I could either buy ART Pipes and just the Shockwave))), or I could buy ART Pipes, the HFC Midpipe, and the Shockwave)))? (I.E. I could put the HFC Midpipe in to an ART/Shockwave system later on)? Also, what exactly is the "resonated" midpipe? I've read some discussions on it, but havent seen anything about what it actually is.

 

OK, so the ART pipes will bolt straight up to the Shockwave system, that will result in a complete exhaust from the manifolds back, that will have Helmholtz chambers on the ART's, a resonator in the section behind the Y-pipe, and Helmholtz chambers in the axle back section.

As for your second example, you'd get the ART pipes as normal, but then ask for the Shockwave with the optional HFC mid-pipes (the HFC appears between the resonator at the Y-pipe joint and the Helmholtz at the axle back.

Remember the HFC/resonators are optional/modular sections of the Shockwave.

As i understand it, Tony has made it so you can change out the straight pipe (standard Shockwave mid section) with dual cats, or dual resonators (mufflers).

Both these options will cut down how loud the system is, they do not affect rasp levels, the Motordyne range never has rasp, ART pipes are so made to eliminate it, as is the whole Shockwave system.



Think of the modular parts for the XYZ pipe (Y-pipe) it has straight, resonated or HFC as modular options.
The Shockwave system is the same, it has straight (default/stock) or you can change that to resonated or HFC's.



ART = Test pipes with special Helmholtz design to eliminate rasp *and* increase the power/torque that you usually lose when fitting standard test pipes.

XYZ = replacement Y pipe with the merge point specially designed for the best power/torque combo. Also has the 3 modular options, straight pipe, resonated or HFC.

Shockwave = Replacement cat-back system, designed for max flow/power/torque on the road. Includes everything from the XYZ Y-pipe and backwards. Has 3 modular options, straight pipe, resonated or HFC.

 

Probably the best exhaust explanation I've gotten. Thanks