Those two intakes go into a throttle body on each side, just like the manifold on the right. You can't have two intakes going into a single throttle body its just not possible. The manifold on the left is from a DE 350z from years 03-06 and the one on the right is from a HR 350z years 07-09 which all had dual throttle bodies.

So whats the upgrade doing? Shorter runners? Boring it out?

Shorter runners making it have more mid range hp and tq which in my opinion is what this car needs more of. Up top it loses like 2-4hp or something like than and your really not going to feel much of a loss, if any. If your REALLY interested in getting it done, PM DEpointFive0

actualy the HR intake manifold has longer runner than the VHR
it make more torque down below and this came from the longer runner alone.
http://www.the370z.com/diy-section-d...take-swap.html


I modified one about 2-3 year ago and a tune is not needed but it would be best to actualy retune the ECU. I also confirmed the gain that HR intake manifold provided , definatly not for the top end since the slightly longer runner moved the peak lower by about 750rpm

back to back dyno testing , same day within 2 hours of each test. (tuned)
http://www.the370z.com/members/megan...e-manifold.jpg