and went to dinner in the miata... and the ******* BOV didn't vent at all, even at 16 psi. It was working fine when I parked it this afternoon.

What do you use to lube the piston? I gave it a light coating of Mobil1 10-30 last week.

 

Seems like you're having a similar problem with the GFB as I had with the older-style FM BOV. I've just really come to dislike piston type BOVs in general. My el-cheepo Greddy knockoff has served me very well so far.

BTW, I found the picture of the adapter I made. From left to right are the original horn that came with my BOV, the adapter I lathed to accept the K&N filter, and the big hunk of solid aluminum that I made the adapter from. What a pain that was...

 

Hmm. Let me explain a bit more to see that we are on the same page. Two lines going to the intake manifold with check valves, the check valves facing different ways. So one line will allow boost to reach the top of the valve and one allowing vacuum. But both from the same source... Is that how you did it or do you have the vac line run to a constant vac source?

 

Also, you mentioned getting a boost leak when you soften the spring tension. Are you testing just by pressurizing the charge pipes or are you getting boost pressure to the top of the valve as well? You need to do the second if you aren't...

 

testing by going out and putting my foot down

 

lol