Okay so last night I had trouble sleeping & decided to channel surf till I fell asleep. Around 2am this show called Tricked Out was on & the guy on there was adding something called a Plenum spacer to a Nissan 350z.
In short here is the definition to a Plenum spacer:

"You will definitely feel this one. The stock plenum slopes down towards the front of the engine. Nissan designed this in order to clear the stock strut bar and hood on the 350Z (function after form). This sloping design restricts the airflow to the front cylinders, but an aftermarket plenum can help the front cylinders breathe. Aftermarket plenum spacers either increase the overall height or remove the downward slope in the design, allowing more volume and greater airflow to all cylinders. Higher airflow is needed to achieve more power."

My question is do they make something like this for the G8 and if so would it be worth it?

the plenum spacer is one of the most common mods for 350z and g35 with vq35 engines.... i havent heard of any plenum spacers for other vehicles so i assume no?

I take it because of the way the plenum slopes to clear the strur bar on the 350z. That being said if a spacer was to be created for the G8 would it be worth it?

So did they need a new hood for this spacer since it re-angles the TB? If not then why does Nissan put it there in the first place for hood clearance issues? I'm confused. :confused:


But with our cars not sure if it'd do anything or not. I know my buddy Matt put a spacer on his F150 and it'll bark the rear tires with it on, take it off and nothing. Slap it back on and CHIRP. So its gotta be making a difference.

So did they need a new hood for this spacer since it re-angles the TB? If not then why does Nissan put it there in the first place for hood clearance issues? I'm confused. :confused:


But with our cars not sure if it'd do anything or not. I know my buddy Matt put a spacer on his F150 and it'll bark the rear tires with it on, take it off and nothing. Slap it back on and CHIRP. So its gotta be making a difference.
The only thing that they had to do was replace the strut bar with one that runs in front of the plenum as oppossed to running on top of it. The hood remained the same.
Seems like a really simple cost effective bolt on if you ask me.

There used to be lots of talk about Phenolic Spacers a few years ago. Don't know if there are applications for V8's or not.

As a current 350Z owner (along with my G8 of course) I have a plenum spacer on mine along with a CAI and exhaust. I added my Motordyne 5/16" plenum spacer after the other breathing mods and a tune. After a retune, post adding the plenum spacer, it does make quite a bit of difference and with a 5/16" space I didn't have to replace my strut bar (it's a pretty tight fit). If you go 3/8" or higher you do have to modify the strut bar.

I'm pretty sure the VQ is the only engine that has the plenum spacer capability that I've heard of. If they did make one for the G8, I'd definitely be the first person in line to purchase one as they do make a pretty big difference for such a simple mod. It added 10-15 whp on a V6 so I can only imagine what it could do for the L76.

The L31 engine from the 96-99 Chevrolet 5.7L also can use a plenum spacer which the those guys with them say its worth about 12rwhp for them in the trucks.

Heard about this a lot too when I had my G35. The VQ engine is not very mod-friendly, but the spacer was the main one people talked about. Intakes didn't make big gains, tunes either. I just don't think there's much left on the table in terms of increasing the power on that particular V6. I've never heard it mentioned for other applications either.

they make spacers for the honda k series its a machined box you bolt under the manifold.

they also make it for the v6 honda motors also.
some honda v6 had one from factory right under the runners to improve low end torque.

but i dont really see where they can put one on our motors. a throttle body spacer but nothing under the manifold it would only increase the runner lengths not plenum volume