I picked up one of the purple topped Greddy style bovs on ebay. Same exact https://www.miataturbo.net/forum/sho...ght=greddy+bov

And, I have a few questions: It did not come with intructions, so what are the functions of the two vac nipples on the back of it? I know it needs vaccuum signal, but I expected there to only by one nipple, and the two nipples are not the same diameter - the bottom one is the normal diameter for vac lines and the top one is larger. What do I connect these to for it to work properly?

Second question - I also purchased a weld-in flange for the bov, and welded that into my intake piping just before the TB. But my problem is in finding a fitting to put into the intake piping pre-turbo that is large enough in diameter to fit in a tube coming from the bov - the bov's outlet tube is like an inch in diameter. Too large for something like a brass hose barb that I could drill and tap into the intake tube. Any suggestions?

Thanks
-Ryan

 

Top one gets vac source from after TB, so off of the Intake.

Bottom one is optional, but by putting it PRE TB, you will find it responds a hair faster.

So TOP = after TB vac source
Bottom = PRE TB vac source (optional)

Take a picture of yours and show the fittings, I'm curious about the size variation. Typically they are identical sizes.

 

top = vac/boost source
bottom = boost source only