Installing ceiling rack between joists

I have a bit of an unfortunate situation. I have odd spacing of the joists in the ceiling of the garage and it impacts how I can install the ceiling rack. I created a simple diagram that shows the ceiling structure from top down view and included the points where I plan to install the rack supports/brackets.


So the problem can be seen on the M1 and M2 mounting points, they are located between the J1 and J2 joist. I was considering putting some form of support that can connect perpendicular to these two joists. I'm having trouble deciding what to put in there. Any suggestions or solutions regarding this?

 

Lay 2x4s flat on the ceiling, perpendicular to the joists, spanning from J1 to J4, or a little bit past so that the ends dont split. Drill pilot holes for your fasteners and be sure you hit the very center of each joist. Omit the blocking at m1 and m2 in favor of the surface mounted 2x4 (flat).

Seems like it should have more than 4 fasteners.

 

The mounting brackets (purple) have (2) lag bolts each, so (8) in total to fasten to the joists. My red X mark is only to note where the vertical support connects to the bracket.
If I ran a 2x4 from the J1 to J4, wouldn't that create issues for trying to fasten to the 2x4 near J4? Since the mounting bracket was positioned right where the 2x4 would be fastening into the joist, wouldn't the fasteners interfere with each other?

 

Doubtful. A 2x4 is 3 1/2" wide so there is plenty of room for multiple fasteners. The reason I suggested predrilling is so that the end doesn't split when you put multiple fasteners in close proximity.

Your flat 2x4 is fastened to the joists... Your rack only needs to be fastened to the 2x4s so you can also move those fasteners off to the side if needed.

 

I was able to get a few photos from above. Not sure if this changes anything with regards to the advice, but thought I should add them here.

 

If I were doing this, I would put two short 2x8 nailed together using joist hangers between J1 and J2 where ever they are needed ( total of 4) then pre drill and use 2 1/2 " or 3" lags through the sheet rock. That way there is no exposed 2x4 .

 

If you have access above then adding blocking between joists would be a good idea.