What's the difference between buynig a plenum or a spacer besides $50?? I don't see the difference and would rather have a new plenum for looks then the stocker with the spacer. Thoughts?

 

If your referring to the MREV lower plenum then you will not be seeing it once it is installed, the spacer is actually more visilbe. If you are refering to an upper plenum then yes you it is a visual upgrade as well as a performance.

I suggest visiting motordynengineering.com and see for yourself, as well as doing a quick search as to which is more popular for what reasons. In either case you can't go wrong.

 

if you're planning other upgrades in the future, like a new exhaust, it's better to go with the new plenum (i think a lot of people recommend crawford, but kinetix is an option too).

the spacer keeps the stock look somewhat (because the oem engine cover fits -- at least when it's 5/16), which comes in handy if you have to bring it into the dealer to get something warranty-related fixed.

i think you have to cut the cover or get a new cover if you get a new plenum. (if you *want* a cover, that is...)

performance gain is probably about the same for both...maybe marginally better for a new plenum?

 

less more area = more "stored ready to use air" = better throttle response and top end..

whats the difference between plenum & plenum spacers vs manifolds (mrev).. spacers increase area... manifolds modifies the runners.

 

kintex plenums look like they have an area to fit in the sways for the z. Wouldn't this sacrifice the volume gained by replacing the plenum. Afterall, the reason to replace the stock was to increase the volume.