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pros and cons of different plenum spacer sizes ?

Old Aug 27, 2007 | 04:13 PM
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pros and cons of different plenum spacer sizes ?

What are all of the most popular sizes, and what are the pros and cons of the different sizes ?

5/16 and 1/2 seem to be the most popular.

Is the isothermal for higher temp climates ?

Where is everyone buying theirs ?

thanks
 
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Old Aug 27, 2007 | 04:29 PM
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Originally Posted by 68_GT
What are all of the most popular sizes, and what are the pros and cons of the different sizes ?
Only thing I can think of here is the engine cover won't fit with the bigger spacers.

Originally Posted by 68_GT
5/16 and 1/2 seem to be the most popular.
5/16 seems to be the best bang for the buck.

Originally Posted by 68_GT
Is the isothermal for higher temp climates?
Isothermal is just a gasket that keeps the intake plenum's temp down. It doesn't matter where you live, if you take off your engine cover, you will see the metal gets hot really fast. So there is an advantage to using the Isothermal anywhere.

Originally Posted by 68_GT
Where is everyone buying theirs?
Check our marketplace. There's link that'll lead you there right up top.

Originally Posted by 68_GT
thanks
No problem
 
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Old Aug 27, 2007 | 04:29 PM
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i would also like to knwo the pros and cons of 5/8 versus 1/2. and i dont wana search so ill let the OP get flamed for asking. have a nice day
 
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Old Aug 27, 2007 | 04:41 PM
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thanks dofu

as the above stated what about the 5/8 vs the 5/16 vs the 1/2 ??

not too worried about the engine cover really.

I tried to search I just ended up finding all kinds of random info including wheel spacers. Don't have the time just want to know ha ha sorry
 
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Old Aug 27, 2007 | 04:55 PM
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Originally Posted by 68_GT
thanks dofu

as the above stated what about the 5/8 vs the 5/16 vs the 1/2 ??
Or would MREV2 be better for you? It depends on which motor you have.
 
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Old Aug 27, 2007 | 06:21 PM
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This is something I wrote in a different thread also asking about the differences between spacers:

I believe the reason most Gs go with the 5/16 is due to 2 factors: 1) the 1/2" gives more gains at the top end of the RPM range (or so I've read on this forum), but more people who are daily drivers would prefer midrange RPM increases which the 5/16 is suited for, and 2) the 350Z/G coupes can't fit the 1/2" under the strut bar, so most of the used ones for sale are the 5/16. Likely, many sedan owners just get the 5/16 because they see others with it. For these reasons, I think most people go with the popular 5/16. Personally, I have a 1/2" on my FX35 which I love, and I'm looking to install either a 3/8" or a 1/2" on my wifes G35 sedan.

To answer g35sedan5at and 68_GT, I've never seen a G35 running a 5/8. In fact, I don't think many people do that. Not sure it will even fit under the hood on this car.....perhaps it would on an FX. I would think though, through a process of continuation, that if the 5/16 produces mid-RPM range gains, and the 1/2 [8/16] produces upper-RPM range gains, then the 5/8 [10/16] would only provide very top end RPM gains. IMHO, stick to something that's been proven to work on the G35.

And concerning the MREV2 lower plenum, that part is only designed to work with the VQ35HR, not the VQ35DE in our G's. According to the MotorDyne website, all of their dyno tests have been on the REVUP engine. You are not going to get substantial gains with one of these. Save your money. Get a spacer.
 
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Old Aug 27, 2007 | 06:44 PM
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WHAT DO YOU GUYS THINK OF THIS PIECE ..??




http://www.z1motorsports.com/350_g35...oducts_id=2132

FOLLOWING COPY AND PASTED
APS has developed what is arguably the ultimate inlet plenum for the 350Z in high horsepower naturally aspirated and forced induction applications. Benefitting not only from a greater internal volume, but more importantly, designed specifically for evenly balanced air flow at high air mass-flow rates.

With a clear an uncluttered path, the APS plenum eliminates much of the energy lost through "turning" the air into each intake runner over such a small volume and obstacle course as found in the stock plenum at.

In day to day driving conditions, the APS Tall Boy plenum delivers crisp throttle response and higher torque - resulting in an even more enjoyable drive. And the higher the horsepower, the wilder the ride!
 
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Old Aug 27, 2007 | 07:55 PM
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APS tall boy is nice, I personally have the crawford V5 plenum and they essentially do the same thing. Get spacers if you want more of a stealthy mod.



I have heard for the 1/2 spacer you lose lower end torque and gain top end power (which most people dislike) and also its more expensive...don't quote me on that though.
 
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Old Aug 27, 2007 | 09:36 PM
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Originally Posted by GixxerSteve

To answer g35sedan5at and 68_GT, I've never seen a G35 running a 5/8. In fact, I don't think many people do that. Not sure it will even fit under the hood on this car.....perhaps it would on an FX. I would think though, through a process of continuation, that if the 5/16 produces mid-RPM range gains, and the 1/2 [8/16] produces upper-RPM range gains, then the 5/8 [10/16] would only provide very top end RPM gains. IMHO, stick to something that's been proven to work on the G35.
i have the skunk2 5/8 and i like it. alot of people on the forum actually have it.
 
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Old Aug 28, 2007 | 02:08 AM
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Originally Posted by Socal_G_sedan
I have heard for the 1/2 spacer you lose lower end torque and gain top end power (which most people dislike) and also its more expensive...don't quote me on that though.
Okay, I'm quoting you but I'm actually not

Through my research, I found the same to be true. 5/16 spacer FTW.
 
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Old Aug 28, 2007 | 02:28 AM
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5/16 is the best bang for the buck you can get.

The APS tallboy is the best plenum out there but N/A won't get much more from it, maybe 1hp.
 
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Old Aug 28, 2007 | 11:50 AM
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6MT Coupe
5/16 spacer gives you the most torque gains through out the rpm range compared to the 1/2.
1/2 gives you 1-2 maybe 3 more hp at the very top rpm range. Good choice if your running track for example.
MREV2 is specifically designed for rev-up VQ's according to Motordynes web site, though will work on non-revup too.
They had the MREV2 before the VQ35HR was even in production. There's no mention of a collector mod for the VQ35HR from them yet, so I disagree with GixxerSteve's statement saying the VQ35HR is the revup VQ in his last paragraph. Revup VQ35DE is the 298hp and the non revup VQ35DE is the 280hp. 07 coupes are an exception with hp ratings advertised with required SAE corrections.
Running both MREV2 and 5/16 spacer resulted in the most gains overall on the revup VQ35DE.
Though I've heard/read elsewhere with that combo on the rev-up's you could become lean, so a fuel mapping tune is a good idea imo.
+10 on the iso thermal. My plenum gets hot enough to fry an egg on it. Heated air prior to combustion from TB and plenum just robs hp.

Read, learn, become knowledgeable
http://www.motordyneengineering.com/G35.htm
 
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Old Aug 28, 2007 | 01:11 PM
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Originally Posted by ttrank
5/16 is the best bang for the buck you can get.

The APS tallboy is the best plenum out there but N/A won't get much more from it, maybe 1hp.
can you go more into detail about the two:

5/16:

vs

aps tall boy:

if its not too much trouble for you .

"oh wise one"

 
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Old Aug 28, 2007 | 06:20 PM
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Wow, disregard everything I said then.
 
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Old Aug 29, 2007 | 12:03 AM
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Originally Posted by GixxerSteve
Wow, disregard everything I said then.
at least the part about MREV2 being for the HR (I was going to mention it yesterday but didn’t want tot start another squabble)...

On a side note... for anyone looking for info about plenums and spacers - there is more info on these subjects than anything else out here... it is probably the best to review previous threads that have very detailed info including much testing... sometimes the more the same info gets repeated, the more convoluted it gets.

You really won’t find new answers by asking an old question.
 

Last edited by OCG35; Aug 29, 2007 at 12:08 AM.
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