Hey anyone with the Motordyne spacer I want to ask you to do a test to see if anyone else has the same problem I had with mine. I added a oil catch can to my car so I removed the upper plenum to clean out all the pools of oil that collect in the lower half. I installed new plastic spacers that get installed on the six center bolts. After going through the correct torquing sequence I started the car and immediately could hear air being sucked past the six center bolts. After that I could no longer hear air leaking but found that if I pressed my palm against the pocket of each bolt, I could feel a vacuum pulling on my skin. I ended up purchasing bonded washers Like the Z1 spacer kit uses to solve the problem.
Here is the test . Take a cup of water and fill the six fastener pockets at the center of the intake, then start the car and see if the water disappears. If it does you have a small vacuum leak you didn't know about.

 

So you're asking to put water in there with the expectation that it will be sucked in ? Let me get right on that.

 

 

How about seafoam. Why would you use water?!

 

 

water? How about some brake cleaner instead

 

 

When i ran the 5/16 MD spacer years ago, i put a small amount of RTV underneath the washer that was with the six middle long 10mm bolts to maintain an airtight seal. I even put rtv in between the spacer and top/bottom plenum for safe measure. Way too many spots for a vaccum/boost leak with the oem plenum.

 

I welded mine shut after I cut the 6 towers out...

 

 

 

Its good that you shared your experience. Because i bet my kidney that folks are driving around right now with a plenum spacer they installed themselves and have a vacuum leak they are unaware of.

 

I'm thinking of tapping mine for threads and installing short bolts with sealant just to plug the holes.

 

Hmm, ive never thought of this.