Plenum spacing plate

Saw this online

https://www.ebay.com.au/itm/Spacing-Plate-10mm-to-suit-Nissan-Pulsar-GTIR-Plenum/233054115822?hash=item36431b97ee:g:7kMAAOSwmXpcGMg~:rk:10

So whats the deal, I see don't why the standard volume of the plenum is less than ideal for most 1800/2000cc applications?, plenty of R's are just fine. Thought I would share for conversation....

Rule of thumb it needs to be the same or greater than the volume of the engine other wise the plenum restricts the flow of air for an N/A engine.

I imagine it's less so for a turbo being a pressured plenum, but mabe reducing the air speed in the plenum by having a greater volume will slow air across the top of the tb's meaning better flow into the engine?

Spacers can also be made out of a thermal insulating material to help reduce inlet temps by reducing heat soak through the plenum.

All interesting stuff and on my list of things to look into and potentially get some made!

I dont see how this could be fitted unless the entire engine is removed.
There's barely a hairs width to remove the existing inlet manifold which would then foul the bulkhead?

Reading the description, it looks like this spacer is designed to be fitted with one of our plenums onto a different 4cyl engine; unless im having a senior moment??

^ I did think the same. I can’t remember but pretty sure some group commonly uses our plenum on their na’s

Nissan put fair bit of effort in our intake plenum and exhaust manifold .
Main reason on smaller capacity is throttle response and better wide rpm range support over gains in just one rpm area . They done good on throttle response and power delivery and a decent tune R still pretty chirpy compared to modern advancements .
Is one of those things with massive amount of maths, accoustics and resonance magic with varying opinions on what exactly best and none of them potentially wrong or right .
you see much bigger benefits from pre plenum intake design and intake flow work on standard quads and plenum over volume spacers .
Gets used as a cheap graft a lot, easy make custom covers as well change shape and plenum feed position .

I thought about a custom cover at one point because Im running a single throttle body couldn't be arsed in the end. I always thought the standard was alright, but never researched or put math behind that decision lol