Pretty much exactly what I was thinking. I don't trust that vacuum source based on what you are experiencing.

Something is not right. At idle, my single piston opens with the blue spring, which is actually the one I'm staying with. Closes at part throttle on accel, but opens correctly on throttle lift.

Oh, and don't anneal the spring. It will loose its properties and will either not have spring action, will break with use, or both. Cut and re-grind if you must, but better, find the problem.

Do you have one of those quarter sized spacers in there or something? Something you can try just for the hell of it is to remove the small plastic piston temporarily and see if you get surges.

It's also possible that your line might be getting pinched or even closed shut from the vacuum.

3/16 line is fine. That's not a problem.

I talked to Forge this morning. They said what I'm hearing is not compressor surge but BOV flutter at lower PSI's. I am a bit skeptical because I have been warned many times that lots of people think they have "cool" BOV flutter but its really compressor surge, so I took a quick video (give the link a try, not sure if it will work).

http://i745.photobucket.com/albums/x...1A1141B0F3.mp4

Link works.

Listening to it.. and it does come off as a surge and not bov flutter.

Your vac source may not be strong enough to hold it open. Also if you're shifting with part throttle you could be taking away vac from your source and the bov never fully opens. And this bov is not adjustable is it?

Are you able to snap a pic of the engine bay? I'd like to see your vac source and where the hose is connected.


And per forge's site on this bov...
AT MOST, even my Greddy FV holds enough at 'very' low < 5psi to create compressor surge. But when I'm on the throttle or do partial throttle shifts I still get no more than 2 choos and then release PSSSHH!

Will do. Nope, not adjustable. If you listen closely in the video, you can hear it open on the second shift for a split second, as I was trying to explain.

One of my friends is coming over later, I'll try revving the car and having him listen closely under the hood.

As a test, try disconnecting BOV from vaccuum source and see if it changes the way it works at all. (when your friend comes over)

Btw, you realize you can rev the car from under the hood right? Just twist the throttle at the intake...

Ohh thats not a bad idea. I will have to find something to plug the line so I don't have a huge vacuum leak.

Don't worry I'm not THAT noob ;) Its just tough to tell because my BOV is on the turbo side of my system.

Wait, what?

While you CAN place your BOV there, it is by no means a good spot. Move it to about 6-10 inches from your throttle plate if/when you can. The exact distance may be off but you have it on the right side.

^^ This

I want to see what the setup is under the hood :dealwithit:

I bought the IC and piping used and thats where the PO placed it, but have been having too much fun driving the car to want to move it yet.

Pics tomorrow!

there is nothing, at all, wrong with having it on the hotside.

at all.

It appears you are correct... but this is from the Turbosmart installation instructions:
https://www.miataturbo.net/attachmen...1&d=1412917726

It sounds like surge is coming from the compressor for sure. Here is something odd. The valve looks to be functioning just fine...

http://s745.photobucket.com/user/Bamfunkified/media/99E31828-8CF2-4120-818F-1C5F589251FE.mp4.html

Here are under good pics. Notice the T from the boost gauge line.

https://www.miataturbo.net/attachmen...ine=1413073454
https://www.miataturbo.net/attachmen...ine=1413073454

https://www.miataturbo.net/attachmen...ine=1413073454

https://www.miataturbo.net/attachmen...ine=1413073454

https://www.miataturbo.net/attachmen...ine=1413073454

Picture is supposed to show where the Vac/boost line is connected at the manifold, as well as the BOV. Also some reasonable level of photo quality is preferred. People want to help, but you're not cooperating.

*edit* you slipped. Some more pics in. I'm still trying to follow the hoses with some lack of success.

either I'm seeing things, or you literally routed the vacuum lines around the whole bay. how long is the line in total from the manifold to the bov? I'm just curious

T off this red hose here, cut the extra and report.

https://www.miataturbo.net/attachmen...ine=1413073454

Also how stiff is this hose?

Good catch. Is the clear hose collapsing?