Got my 5/16" Plenum Spacer installed today in a record breaking 1Hr 20 min. Haha, yeah right, but I wanted to double check all my bolts to make sure they were all the same Torque. I ended up using a hand ratchet to finally Torque the bolts completely. Thought it worked best.

Overall thoughts, I notice a little more pep in the middle gears. Before, I wouldn't notice the pick up until I hit around 3-4 thousand RPMs. A lot sooner now. Thanks go out to TTrank and others for the idea.

i just put mine last week and i love it. just installed a stillen intake last night. car sounds sweet

Very nice. Infiniti should have a TSB to add the spacer since it helps so much!

Im kinda slow on the engine mods, what does the spacer do?

It goes below your Plenum and allows more breathing room.

more HP to the wheels and a better sound Im guessing

Not so much as it is more power. I believe it is 10-12 extra at the flywheel, so about 2-3 to the wheels.

Spacers are the best bang for the buck IMO (and many others' opinions). To expand on what G'd Out said, the purpose of a plenum spacer is to raise the upper plenum to alleviate an airflow restriction that exists above the first two intake inlets. From the factory, the upper plenum is very close to the lower plenum runner inlets...there is only about 1/8" gap between the first two inlets and the upper plenum. This creates a significant air flow restriction that reduces engine breathing and power output; imagine the amount of air that first two intake inlets need being sucked through a gap of only 1/8"!! A spacer frees up the airflow restriction so the engine can perform to its potential.

5/16 ISO spacer is on my list for sure. I was worried that it would effect power at lower RPM and it sounds like it does but for the better huh?? I just want some more down lower in the RPM range.

What do you recommend?
5/16 or 1/2 spacers???

5/16 has a better power over the rpm range. The 1/2 spacer will giver you 2-3more horsepower at the higher rpm range. So this is what I read.

What is the the general idea about adding a throttle body spacer? Is there any gain?

Sorry to post here, but no-one on the '07 forum seemed to know. Any idea if this would also help a V35HR in an '07?

Lol I asked Kinetix and motordyne and they said there are no parts available for our car yet maybe a couple months or so.