I am sure many people who reads this g35driver forum also reads my350z forum as well. I have notice that many people here (g35driver forum)favor the Motordyne plenum spacer, and over in the (my350z forum) members favor the AAM Spec Angled Plenum Spacer. I have made this conclusion because there isnt a discussion about the AAM Spec Angled Plenum Spacer at all in G35driver forum and vice versa in my350z forum. Why is that? IMHO these two are great products and they are very similiar therefore they are direct competitors. And I am surpise that there arent and discussions about AAM Spec Angled Plenum Spacer vs Motordyne plenum spacer.

AAM Spec Angled Plenum Spacer:
Web site: http://www.alteredatmosphere.com/350z_1.asp
its an angled spacer
claims 10hp
remains factory look
Price: $249


Motordyne plenum spacer
Web site: http://www.motordyneengineering.com/
Flat spacer
claims 5~10+hp
offer in different sizes with different prices: 1/4" ($195) , 3/8" ($215), 1/2" ($245)


So which spacer do you guys think is better in performace wise? Since the prices are about the same we do not have to worry about that too much. Even thou they are both spacers the design and idea involved is very differnt. AAM uses the angled one, claims that making the plenum flat will increase flow to the front cylinders which then increases HP. Motordyne just simply increase the height of the plenum by a flat spacer to increase hp. Im trying to make a decision to buy one of these...

 

Eugene, I also found it funky how 350Z Forum seems to be oblivious to the Motordyne product and over here nobody knows about the Altered Atomsphere spacer. Without any direct comparison there is really no way to tell which one is the best.

AAM, Motordyne (1/4, 3/8. 1/2"), Kinetix, Crawford old, Crawford Cast......

Frankly I believe the stock plenum was designed with a slope with specific reasons. 350Z crowd is not as fortunate as us because they have the front upper suspension brace to deal with. At most they can use a 1/4 Motordyne spacer unless they opt for a different brace. That's why I think most 350Z owners are more interested in the AAM design.

 

I also agree with Sukairain about the "the stock plenum was designed with a slope with specific reasons", IMHO I think AAM spacer is a much better alternative than Crawford plenum, it has the same idea of flattening out the top of the plenum by having a angled spacer and without the hassel. But yea since the stock plenum has a slope, IMHO keeping the slope and use the motordyne spacer is the best way.

 

Bump...

No one has any thoughts on this??

 

The AAM spacer is angled. The Motordyne is not. Both serve the same purpose of increasing upper plenum volume and thus increasing the balance of air flow to all cylinders, especially the restricted 1&2 cylinders in the front. My feeling is they both do the same thing of increasing plenum volume so performance wise they both should be very close in numbers. If one performs better than the other it shouldn't be much.

 

Only thing I have to say is, I like how AAM posted the actual dyno off the dyno machine showing hp and torque.

 

But isnt the motordyne also have dyno data as well?

 

I believe Gsedan35 is refering to the fact the DynaPack dyno charts from MotorDyne isn't a 'scanned' paper print out like the ones from AAM.

Unfortunately DynaPack doesn't have the cool run file export like DynoJets. It simply exports to a .txt file that can be imported into a spread sheet program (i.e. Excel) to be plotted. That in itself is prone to 'alteration' ... but really, if you know what you're doing ... the DynoJet files can also be altered then printed out.

Also, just to better inform those that are still confused. The AAM spacer itself is 'angled' and when installed 'levels' the plenum. The MotorDyne spacer is 'non angled' (constant thickness all around) and when installed retains the oem plenum 'slope'. Fluiddynamicly speaking, the latter is more ideal to balance the flow velocity from the rear intake runners to the last set in the front. Both will achieve an increase in plenum volume that is desirable and give a little more peripheral scavenging to the front pair of intake runners.

 

Yea, it is a good point that they do not use dynojets... After reading several Motordyne reviews seems there are few negative post about not having solid gains vs the AAM have some solid gains shown on their website...
can some one give in some insight?
and isnt this AAM angled spacer has the same idea with crawdford? flatten out the top of the plenum?

 

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