Tim,
The ports give you the ability to fine tune your blow off valve to your set up. Everyone has different mods and different boost levels. With the Synapse BOV you can set it up for your driving style, mods or boost levels

reference this thread for some useful info about the ports and how they worked out for a fellow EvoM Member:
https://www.evolutionm.net/forums/ev...installed.html

 

I would go with the APS dual vent.

 

aps ftw

 

APS. Simple, adjustable, works flawlessly for me @~30 psi.

 

aps dual vent ftw

 

the aps is adjustable?

 

I have the synapse bov and it holds better than my crushed Evo 9 bov did. I was actually hitting more load and boost. I had to turn my boost controller down.

 

who sells aps bov's? im seeing that its out of stock on most vender sites..

 

from what I heard they stopped making them and you need to find used ones

 

I've had my Forge RS bov to 46psi. Held like a champ with no leaking.