Rev-Up airbox on a VQ35DE - special note
It's what I could get my hands on. I had 2 G airbox deals sold from under me.
I think 60-70 shipped is the going rate.
I paid $60 shipped for mine, and I think I got a pretty good deal. It's definitely worth it WITH an aftermarket drop in filter. Or even a NEW oem filter would probably be alright.
Just got done swapping the V-stack from the rev up Z to my oem airbox. Won't have any thoughts until tomorrow.
FYI. The Z airbox is an entire box (not like the G where the two halves are clamped together). But the Z airbox CAN be seperated in halves. And the maf side of the Z airbox does house the filter fine and fits the other side of the G airbox. But there are some problems:
1) To make it work, you'd have to unclamp the bottom portion of the G airbox resonator. Not a big deal.
2) When you put the two halves together, although they do mate, the clamps that would hold them together don't match. Again, not that big of a deal but a pain.
3) The bottom portions that house the resonators don't match but it doesn't matter as it would be totally cut off anyway.
4) The little extension that features a 10mm bolt to secure the maf side of the airbox isn't long enough on the Z airbox.
Basicly, it's a waste of time. But since I had an extra Z airbox, I tore one up for giggles.
FYI. The Z airbox is an entire box (not like the G where the two halves are clamped together). But the Z airbox CAN be seperated in halves. And the maf side of the Z airbox does house the filter fine and fits the other side of the G airbox. But there are some problems:
1) To make it work, you'd have to unclamp the bottom portion of the G airbox resonator. Not a big deal.
2) When you put the two halves together, although they do mate, the clamps that would hold them together don't match. Again, not that big of a deal but a pain.
3) The bottom portions that house the resonators don't match but it doesn't matter as it would be totally cut off anyway.
4) The little extension that features a 10mm bolt to secure the maf side of the airbox isn't long enough on the Z airbox.
Basicly, it's a waste of time. But since I had an extra Z airbox, I tore one up for giggles.
Small update. After driving with it for a few days, it's still difficult to tell. I recently swapped my coupe 19s back on. I usually feel the car get slightly more sluggish when I swap to my oem 19s as the old set had rock heavy RE050s. I put new michelins on and saved a 2-3 lbs up front and 5-6 lbs out back. Now when I swapped again, I could still feel a slight difference in throttle response. As the rears are 255s vs 215 and still a few lbs heavier than my oem 17s on 215 blizzaks.
When I added the Z RU v-stack (same as the G RU stack), I could tell it was different (or at least that was my impression). If I was pressed to quantify it, I would say whatever slight throttle response I lost when swapping back to my coupe 19s, I got back with this little v-stack mod. Maybe that and a tiny bit more?
Either way, it was interesting to fiddle with it anyway. I got it pretty inexpensively anyway.
Question is, what if a longer one was added? This RU unit is about 1". The non RU is probably 1/4". One could in theory add another 0.25" or so w/o getting it too close the filter.
When I added the Z RU v-stack (same as the G RU stack), I could tell it was different (or at least that was my impression). If I was pressed to quantify it, I would say whatever slight throttle response I lost when swapping back to my coupe 19s, I got back with this little v-stack mod. Maybe that and a tiny bit more?
Either way, it was interesting to fiddle with it anyway. I got it pretty inexpensively anyway.
Question is, what if a longer one was added? This RU unit is about 1". The non RU is probably 1/4". One could in theory add another 0.25" or so w/o getting it too close the filter.
The revised stack sits within an 1" or less of the filter. Obviously Nissan saw some sort of advantage going with it and saw no need to increase the depth of the airbox to exceed the distance between the stack and filter.
I'm now pretty sure the purpose of the stack was to improve throttle response of the revup since it uses the higher flow intake manifold which deadens low rpm throttle response. By lengthening the intact tract about 1.5" would improve the throttle response and in many cases, low rpm torque. The trade off becomes slightly reduced high rpm performance. I don't feel a loss of high rpm power (it actually feels better). Maybe that's where the large air horn improves things.
I'm just shocked at how much of a driveability improvement these two OEM mods have on the VQ35DE.
I'm now pretty sure the purpose of the stack was to improve throttle response of the revup since it uses the higher flow intake manifold which deadens low rpm throttle response. By lengthening the intact tract about 1.5" would improve the throttle response and in many cases, low rpm torque. The trade off becomes slightly reduced high rpm performance. I don't feel a loss of high rpm power (it actually feels better). Maybe that's where the large air horn improves things.
I'm just shocked at how much of a driveability improvement these two OEM mods have on the VQ35DE.
I've realized an increase in responsiveness across the whole power band... ESPECIALLY in the upper end... I originally noticed how just a touch of the throttle at 70 mph, the engine breathes so much easier and accelerates without any hesitation at all.. it just GOES!! 
As I've said before, with the combinations of intake and exhaust mods, mostly OEM, other than the MD spacer and drop in filter, it has really opened up the flow in this engine... short of headers and test pipes!!
As I've said before, with the combinations of intake and exhaust mods, mostly OEM, other than the MD spacer and drop in filter, it has really opened up the flow in this engine... short of headers and test pipes!!
Any difference would be so insignificant you wouldn’t “feel” it while driving… you would need dyno testing to determine… a 10 ft lbs of trq gain in low – mid rmp range is very significant and easily felt by butt dyno… however, 5hp or less in high rmps will absolutely not be felt from butt dyno. Any claims otherwise is strictly placebo.
Any difference would be so insignificant you wouldn’t “feel” it while driving… you would need dyno testing to determine… a 10 ft lbs of trq gain in low – mid rmp range is very significant and easily felt by butt dyno… however, 5hp or less in high rmps will absolutely not be felt from butt dyno. Any claims otherwise is strictly placebo.
But WOT and high rpm is different. I don't get a chance to do this that much. So, I don't get a feel on how a mod differs. Especially when I went though multiple mods in a span of 1-2 weeks.
So yeah, I agree, high rpm differences are more difficult to feel. Hopefully more will chime in with their opinions. More the better. So far my own opinion of this mod is consistent with others here (for low end at least).
Mike, what is your opinion of this little mod?
Haven’t had a chance to try it yet… still dealing with a bunch of cosmetic stuff in the engine bay… I haven’t even been able to drive the car for 2+ weeks 