I'm hoping you guys can point me in the right direction on this. As noted in my signature, I have a VQ40 08 Frontier. I have done about all the bolt-ons available to me, including cams. While I'm doing OK, I feel something is still holding me back(besides a heavy truck ). My numbers are OK-262whp & 283ftllbs, but should be better I think. I am thinking the problem is my VQ40 intake manifold/plenum. The VQ40 has the variable intake plenum with valves opening at about 3500K. I think my Brian Crower cams are needing better flow than my stock intake is giving me.
I have started looking at two choices-the VQ35de lower intake, upper plenum, with a 1/2" spacer, or the Vg35HR lower intake, motordyne plenum, and 1/2" spacer.
If I understand correctly the VQ40 has the same heads as VQ35's. But I'm NOT sure if this applies to the DE or HR motors or both. Thats were I need the most help. I would hate to buy either of these lower intakes and find out they wont bolt up to my heads properly.
I'm thinking that the DE single throttle body setup(if the lower bolts) would be a fairly easy bolt on for my VQ40. Being a single TB, I'm pretty sure I could still even use my Volant CAI. and electronically I'm sure it would be much easier. However the dual TB setup on the HR would be really cool on a Frontier. Does my slightly larger displacement need the extra air volume from the HR motor or does the DE offer more than enough.
So guys, I would gladly like any constuctive suggestions or opinions on this matter. Sorry if something like this has been posted before, but I doubt any cammed VQ40 Frontiers have been on here looking for a better intake manifold system. Also, I do have Uprev, so getting retuned for a new intake is not an issue.

 

This is the VQ40 upper plenum.

 

vq40 has a higher deck height and therfore the heads are further apart... making the vq35 lower intake manifolds not work... have not tried the HR lower plenum... maybe it will fit... doubt it... have seen VK56 in a frontier though... maybe a better route to go... use V8 pathfinder mounts and you are on your way

 

Thanks for the input. The vk56 doesn't really interest me. My truck is still being paid for so I don't want to go that extreme. So i guess I need to research more into the HR lower plenum. I have heard that the vq40 is closer to the HR motor before also, it's just hard to find more detailed info on either of them.

 

similar in the sense that they both have a bed plate... there is ALOT of differences between the heads though... next time I have a VQ40 apart I will check the measurements... i am pretty sure the deck is still taller the the HR... the rod is like 20mm longer!!!