Hi I've spent the last few months searching through many forums on effective mods for the rev-up vq35de engine.
So far I gathered the Z-tube with K&N drop in filter, and 350z HR y-pipe are the best group of mods that won't kill peak hp/trq while improving power all through the rpm range.

To stay on topic though...after searching through peoples MREV2 and 5/16 spacer mod results, it seems that peak hp and torque are either untouched or drop with the spacer mod.
People have claimed gains in the midrange but whats the use of a 3500rpm- 4500rpm gain when at WOT at the track or in a race you are basically above 4800rpm at all times.

That "Reid-only" guy on here is famous for his amazing 13.7second quarter mile time with his 05 g35(this was with ztube and hr y-pipe). However since that he did the 5/16 spacer and went to the track but didn't have any improved times.

Has anyone noticed a consistent gain at the track after doing the 5/16 spacer and/or the lower plenum (mrev/mrev2) mods?

ok bro so if you have the rev up engine then its not a VQ35DE its the VQ35HR, trust me this forum is really helpfull

and from the research i've done on the HR motors by just doin a MD spacer you wont get any horsepower with out getting the MREV

Its the 298hp 06 rev-up, not the 306hp HR although I wish it was

You seem to be pretty mixed up when it comes to engine designations...

The 2006 Infiniti G35 Coupe motor is a Rev-Up version of the VQ35DE motor. The DE is easily distinguishable by the use of a single throttle body.

The HR motor was never offered in the G35 Coupe. It is distinguishable by the employment of two throttle bodies and of course two intakes.

HR motors have a vastly superior intake manifold design from the factory and therefore do not require a manifold spacer, and to my knowledge no one makes one.

Now that we've got that straight, back on topic, as this is an answer I, too, could use.

I think most people do these mods for daily driving (hence the usable mid-range power gains). If you are looking for improved track times you should probably look the way of forced induction. On the street you can use an additional 7-14hp around 4k rpm. Losing a few peak power is not an issue because you are shifting below where peak hp comes into play.
I havent seen many dyno charts, but the ones i've seen show about 7-9whp with no peak power loss... Then again I havent cared to look since I purchased mine.

OP here's the skinny. Since you have the rev-up motor the MD spacer by itself will provide almost no gains. However when you pair it up with the MREV2 lower plenum it will make considerable gains.

Check out motordyneengineering.com for more info. Here's a dyno that shows very similar gains with spacer or no spacer running on an MREV2 lower plenum.

Do you know of a similar plot that shows the spacer, then the lower plenum?

x2. one that shows the revup with the spacer before the lower plenum mod

Don't think you'll find that. It's well known the best combo and most popular for the revup is only the MREV2 + 5/16th spacer. I do know the 1/2" spacer alone moves peak hp closer to the top rpm end IIRC on a non-revup compared to the 5/16th on same VQ. So hears a thought...MREV2 + 1/2" spacer on a revup. Now there's a dyno chart I'd like to see for track purposes....

True that is the most popular set-up, but i'm sure there is one out there somewhere, im sure someone dyno'd w/out the MREV. Shoot I have a 5/16 + z-tube and K&N, but I have no aftermarket exhaust like a lot of people..Then again I haven't dyno'd the set-up...

+1 on the MREV + 1/2 spacer...Interested.

Hmm that 06 350z on the dyno was a rev up vq35de I suppose. The mid range torque might help in the 60foot with 1st gear..
Before I purchase I'de definitely need to see atleast 2 to 3 more independent dyno tests of rev-up DE engines with the 1/2" spacer and mrev2 lower plenum (as well as 5/16" spacer with mrev2 LP) as thats a pricey route.

get the mrev also... Much better power increase!

Ok from the reviews and dyno sheets I recently came across... the MREV2(one for my 06' 6mt REV-UP) with the 1/2" spacer makes a good rpm range power increase plus a little bit more peak power than 5/16" spacer and Mrev2.

Now that I know the proper MD spacer and manifold combo for my high rpm needs, I will stay tuned for a few more dyno tests to reassure justifying a future purchase.

Ok thanks for your help people I figured out what I needed to know from this thread and I will wait for another time in the future to do the 1/2" spacer w/mrev2. However I am going for the ART test pipes as they have proven to gain everywhere plus up top. Combined with the HR Y-pipe I think ill have a very good recipe.

^Good choice. (ART pipes)

After you get everything installed, tune with Osiris to get even more gains.