Doing some valve cover on a super clean 2000 Maxima and Wow I'm really impressed with the variable intake mechanism....I have a 2003 VQ35 and I think the 2000 VI may be a better design! 6 slider type flaps versus the VQ35's one!!!!! I'm sure if the plenum chamber was a little larger it be an awesome setup for the VQ35......Has anyone ever swapped a 2000 VI intake onto a 02-03 VQ35?

 

nope but my ported im does the job real nicely

 

I've been saying this for a long time. The 00vi has an awsome plenum design. But it chokes up the 3.5 because it doesnt have enough volume to keep up with how much air the 3.5 pumps. Just take the throttle bodies for example, you can swallow the dek throttle body with the 3.5 unit.

We went from a 3.5 + 00VI setup to a 3.5 + 02IM on a 3.5 swapped 4th gen locally and the difference in power was very noticable.

 

It has been done on a swapped 4th gen, but the ports didn't line up between the 00VI and 3.5 in the first place. That IM design/flaps is a lot like the one on the QR25s with the butterfly valves, neat design.

+1... Volume and TB/elbow size make a large difference.

 

[quote=sparks03max;7902076]It has been done on a swapped 4th gen, but the ports didn't line up between the 00VI and 3.5 in the first place. That IM design/flaps is a lot like the one on the QR25s with the butterfly valves, neat design.



not when those screws come loose and destroy ur motor...happens to alottt of qr's

 

All it takes is a little loctite. Mine were loctited before the first oil change (about 500 miles on it) when I bought my spec V...

 

Dynamic supercharging.

 

Resonance ftw...

 

this thread FTL!

 

Reminds me of the old MEVI vs 00VI threads.

 

After grey99 finishes his 07+ plastic manifold swap, it will be that vs the 02VI.... As usual, there will be no conclusive testing and arguments will be a bunch of e-professionals arguing theory and physics.

 

So you have ran the 00VI on a VQ35?

 

Did the same to my spec as well.

 

[quote=maxima dude;7902309] Which ports are you referring too? The inlet ports of the LIM on the 3.5 and 3.0 are different but I believe the outlet ports of the LIM have identical bolt pattern with the 3.0 having wider oval ports and the 3.5 having more circular outlet ports that a little grinding could fix or just using 3.0 heads on the 3.5 block would cure the problem.....the 3.0 ports are bigger!

 

Matching a more circular port to a more oval port would require grinding on both ports, making it a good deal larger. Porting isn't always a good thing, especially when removing large amounts of material and making the head port cross sectional area higher than the intake runner.

There has been a flowbench test of maxima 3.5 heads vs 3.0 heads vs pathfinder 3.5 heads floating around on these forums for years that proves the "bigger ports" don't mean jack. The maxima 3.5 heads outflow the 3.0s by a large margin. I have the feeling that such a head swap may also entail losing intake VTC.

edit: also, the VQ35 heads, even stock, flow amazingly well. SGM has made 350whp NA on stock heads and actually got rid of their ported heads because they lost power.








The head swap I am more curious about is revup heads. They have the same intake/exhaust ports as us, and a Vmanage could be used to control the VTCs...

 

Hrmm, this calls for a few pics out of my personal collection...





I can't find my 3.5 LIM... It's around here somewhere... I'll need it sooner or later...


Sidenote

2,000th post FTMFW

 

Yeah... those look really easy to line up with a little porting.

 

Post whoreo

 

No. I have a full dek. A local had a 3.5 swap with 3.0 heads and 00vi. He switched to a 3.5 IM and gained a bunch of power.

 

Anyone remember what krismax had? Pretty sure he had a full 3.5 swap (sans ECU) and a 00VI, and his powerband was impressive at the time, (gutted 00VI).

Low 13's @ 103-104 I want to think, but his car was lighter than catwalk model.

 

I remember his setup. He also reved that car to the moon at one point in time. And if I'm not mistaken, he also went to an 02IM and ran close times to the 00vi setup without the JWT tune. I could be wrong though.

 

^^^ this!!!

 

Either way, I highly doubt that the 07+ IM "swap" will catch on if any at all. There is way too much custom machine work to be done to the lower IM for it to bolt to the heads.

Also, I think that even if grey99 (or anyone else) eventually gets it to work on a 1st gen style VQ head, it will not make that much more (if any at all) power over a 02IM with BOP, NWP spacers and/or SSIM.

What people overlook when they pop the hood on the A35 is that the IM is not the only change nissan made to the engine. And I'm pretty positive that the extra horses nissan claims to have extracted from this motor mostly comes from the improved head design. (and everything accosiated with the head such as cams, etc) Also, the way the ECU controls all of these "variable functions" plays a HUGE roll in the claimed 290chp. Take the swapped 4th gen with static cam timing we have down here. Even after A/F tuning, it's still not as impressive as a "290hp" car is supposed to be.

 

To bad you did post one of the intake which is the subject....anyway mid range lift of the 3.5 appears to be superior bad the more lift the more the 2000-01 appear to out flow the 3.5....I'm sure the intake will flow more on the 00VI that's why they have the highest flowing injectors....installed on a 3.5 should be impressive.....too say the least! I'll have to compare the head intake tract angles, but these definitely will be the deal if I ever do a 4th gen w/VQ35 swap...

 

Been hangin w/MIKE much lately? Cripes...

Your comprehend-able statement is slightly misleading.

The DEK injectors flow 290cc from the factory(3.0 Bar), and the VQ35(FWD, @3.5bar) flow 315cc from the factory.

The reason I mention from the factory is because I'm sure Nissan engineers weren't concerned with fuel starvation, since they designed them to run @ 3.0 bar (stock FP), which flow less than the VQ35 at their designated fuel pressure.

 

You were saying how the 3.0 has bigger ports (insinuating that it would flow better), so I posted flow bench results that disagree with you. The 3.0 heads flow 20-30CC less than the maxima 3.5 heads at pretty much any lift # on the intake side and are also behind on the exhaust side until .4ish lift. You do realize our stock cams are .378" at max lift, right?

Smaller plenum volume when it's been well proven the VQ35 loves a big plenum, smaller TB (much smaller) when it's already restrictive at 70MM (A 90MM TB and intake got SG 25-30whp gains). Just a couple of reasons that the 00VI is not likely to outperform the 02VI. Hey, maybe it will make more power in the 1000-3000RPM range where you like to live on the wild side.

+1.... I wanted to make that reply nmex! The DE-K injectors only flow more than the stock 3.5 injectors when they are installed on a 3.5 with a higher base fuel pressure.

 

I was hoping I wouldn't butcher it and confuse anyone, and simpler seemed to be better in this case.

I was actually going to sit back for a few because I knew you would probably do it better.

 

Haha NP, I wouldn't have thought to pull out the Mike comment. That was brutal, and awesome.

 

I've been saying this since before (I found out) SG did there plenum with the LS TB.

 

^^^^ Needs write up on this

 

my350z 350z NA build subforum

 

One thing I love about a cable TB is, going to a bigger TB is (for the most part) as simple as finding a way to bolt it to the manifold and attatching the throttle cable.

 

Very true, as long as the elbow supports it or can be easily modified to the bigger size.

However, you can't get a sprint booster for a cable throttle....

 

i love this forum

 

Thanks for reminding me.

 

yeah it sucks that no one makes a bigger tb for the 3.5

 

I wonder if it's feasible to mount our electronic TB components on a q45 TB...
B/c we can't control a GM 90mm electronic TB. Worthless *** ECUs of ours.

 

How much fuel pressure does a VQ35 injector make @ VQ30 base fuel pressure?

 

Does it matter? Off the top of my head it should be around 270CCs. Regardless, your theory about the DEK having higher flow stock to make up for a better intake manifold is still wrong. Stock injectors on the DEK flow 290CCs. Stock injectors on the VQ35 flow 315CCs. The DEK injectors flow more at the same pressure, but the 2 engines do not operate at the same base fuel pressure so that fact is inconsequential aside from the DEK injectors being a nice, easy upgrade to get a little more flow on a 3.5 (I am using DEK injectors, for example).

Take another look at those graphs, I posted them for both intake AND exhaust. On the intake side, the 3.5 heads outflows the 3.0 consistently by a large margin all the way up to .6"+ lift. On the exhaust side, the 3.0 heads barely pass the 3.5 at .4" lift, while being beaten handily at all lift #s below that. Even my aftermarket cams are only .458" of lift. Cams do not instantly reach max lift, and only stay at max lift for a short time. The majority of the valve opening includes the cam being somewhere lower than that so the lower lift flow is very important. The 3.5 heads clearly outflow the 3.0s...

 

Ok I didn't see the intake graph you posted yesterday, maybe the intake tract angle is the difference? I'm sure bigger isn't always better, but I just know the Intake having a VI flap for each runner seems more effective than that VQ35 single flap VI configuration, and it would be nice to have a larger plenum'd setup with the 00VI confiqured flaps instead of that single unit design....I don't think the 00V1 exhibit a big drop/dip(like the VQ35) once the VI is switched to the high flow config.....Anyway I was curious about the subtle differences in the head designs and impressed with the 00VI intake manifold flap setup that's basically it....I'm not presently working on a project to swap over anything just thought it was a bit interesting.....