Does anyone "get" the MREV/Spacer advantage?

The G-Series Tuning Forum is the place to discuss G35/G37 performance modifications and mechanical repair.
The_Scooch
Posts: 50
Joined: Tue May 30, 2006 5:14 am
Car: 2006 Infinity G35 6MT Coupe

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OK, I'm confused.I have an 06 G35 6MT Coupe.

After reading about intake plenum spacers, I decided to get a 5/16". Then I read about the MREV and it said it was specifically designed for the Revup engine. I asked a rep at Motordyne and he said I have that engine. The description says it will add 15HP and 18TQ...Wow!

In our conversation, he described how it works and that the MREV lower plenum is a modified lower plenum for an automatic. This, combined with the spacer gives the desired results. He also said that just adding the spacer to my intake will do nothing because my stock lower plenum already has the short intake ports and thus creates more HP than the plenum meant for the automatic G35. The auto plenum creates more torque because it has longer ports but less air volume due to less area inside the plenum chamber, thus less HP. Follow me?

Now I'm confused...

In my head, putting a lower plenum from an automatic on my 6MT means that now I have the resulting 280HP/270TQ auto engine. 18 LESS HP but 10 MORE TQ. So then adding the spacer for increased volume corrects that and I'm back where I started (hopefully) with HP and I get more TQ.

Does this sound right? It does not seem like a wise decision to me but then maybe I'm wrong about this. I have not installed the system yet so I don't have the "seat of the pants" feel yet.

Anyone have any ideas about this?



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C-Kwik
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I can't testify to whether or not this mod does anything or what gains, if any, you would see, but using this plenum would not put you back to what the automatic versions power and torque levels are. The rev-up version of the motor adds a variable exhaust cam system that switches between 3 phases. I would speculate the cam profiles chaned somewhat as well. Basically, they lowered the peak torque, but broadened the curve. The change to the intake system was only a small part of the change, probably to try and enhance the changes to the motor and make sure fuel and emissions remain optimized.

I did read about this product a while back and IIRC, they claimed higher torque and HP with a small loss of torque up top. As with anything, I would tend to approach it with some level of skepticism. Perhaps do some searching and see if you can find true testimonials with dyno results to see if this really works.

The_Scooch
Posts: 50
Joined: Tue May 30, 2006 5:14 am
Car: 2006 Infinity G35 6MT Coupe

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I found the answer in another forum, complete with dyno results and now it all makes sense.

First, the MREV and spacer do work and here’s how:

The revup engine (6MT) differs from the 5AT in a few ways but one significant difference is the shape and port length of the lower plenum. More torque is needed for an automatic transmission and so to give the 5AT engine a different power profile, Nissan engineers created a lower plenum with long ports. This takes up extra space in the chamber, thus lowering the volume of air while increasing port velocity. For the 6MT, the opposite was done. The ports were made shorter and the plenum slightly dished to allow more air volume and less restricted flow.

The result is in the numbers; the 5AT has more torque and the 6MT has more HP.

Installing the spacer alone on a 5AT corrects the volume problem, thus increasing HP. Nothing more needs to be done to the 5AT. Installing a spacer on a 6MT will accomplish next to nothing and could hurt top end power. The solution is to install the MREV kit. The kit consists of a 5AT lower plenum that Motordyne says they have modified for improved flow, and a 5/16 spacer. The ½ spacer allows a little more volume and the pressure drop hurts the midrange power. The result is NOT more top end power, but instead, more torque and more HP in the mid to upper mid range. The dyno shows approximately a 15 HP increase and 18 ftlb torque increase across the powerband. HP peaks slightly higher than stock at around 6200 RPM, levels off and then drops to about 2 HP less than stock at redline. This test was done on a forum member’s 350Z.

I don’t drive around at the redline so I am happy to sacrifice the 2 HP. The usable HP and torque increases are right where they will be the most fun.

So I figure with an exhaust and a Z-tube, I should get over the 300 HP mark ( a claim I want) while still improving the power curve and driveability.

IronAnaconda
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Joined: Fri Jul 28, 2006 8:15 pm
Car: G35

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can u post the dyno results for adding the spacer to a 5AT? thx

joe603
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The MREV2 is an expensive for 15HP in the midrange ($450)...boost is the only way to fly!

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AZhitman
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I have the Motordyne 5/16" spacer on mine and love it.

The_Scooch
Posts: 50
Joined: Tue May 30, 2006 5:14 am
Car: 2006 Infinity G35 6MT Coupe

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That's not bad at $30 per HP. TT will cost you approx $70 to $100 per HP and SC may cost slightly less or the same.

Hell, an exhaust doesn't really do anything and that's a grand to start.

Did you notice any seat-of-the-pants difference with your spacer?

The_Scooch
Posts: 50
Joined: Tue May 30, 2006 5:14 am
Car: 2006 Infinity G35 6MT Coupe

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I have to go back to that forum and search it again. I'll find it and post here...

Stay tuned.

The_Scooch
Posts: 50
Joined: Tue May 30, 2006 5:14 am
Car: 2006 Infinity G35 6MT Coupe

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Hey, I posted the MREV+ dyno here, as that is the one I had found. I also went to motordyneengineering.com and they have a lot of dyno charts for the various products they make. Alot of them were sent in by customers, so you get to see a range of results.


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