Just got my setup up and running (pretty much a bb kit with 370's and a calum ecu) and have a few questions. I am running blowthrough and have a problem with compressor surge. I am using a greddy type-s and it is at a pretty soft setting. I can hear the compressor surge sometimes for an instant and then the bov works. Could this be because of vacuum issues not letting the bov open soon enough. Still gotta get all of the lines hooked up correctly (vacuum is at 10 when cold). Any input appreciated(besides haters :D )

there are 2 springs in the bov try taking the smaller one out

yeah sounds like a vaccum leak to me. solve it and you should be fine, my bov on my old Mazdaspeed protege did that same thing when i had the wastegate and bov t'd into the same vac source, well then my wg diaphram cracked and it did the same thing your mentioning, would work and then not and cause a little bit of compressor surge, not too bad but still. i just seperated the source for the wg and the bov to seperate sources and everything was back to normal except the fact it was running 11psi instead of 7 but that was fine with me, the car loved it. haha

Rent a vacuum pump from a parts store to adjust the BOV.

ur not supposed to get 10in hg at idle..it should be more like 20..pressure test the system

I'm well aware of that fact t-bags and was just wondering if it was a contributing factor. She boosts 7lbs no problem. I just need a little insight on how to hook up the vacuum lines as ***** has provided information for lowport de's.

even when my car has vac leaks she would hit full boost..ur not going to get the power 100% until u solve the low vac issue.just go over all of the vac line connections and zip tie them

v8killer2001
Can we make this a sticky please? This comes up often, so I thought it would be useful to refer to the following procedure. Here is how you adjust the GReddy Type for recirculation mode:

1. disassemble the BOV by removing the allen screws that secure the purple portion of the BOV.

2. Inside, you will find an inner spring and an outer spring. Remove the outer spring and put it aside.

3. Reassemble the BOV using only the inner spring inside. As you reassemble the the valve, be sure that the adjusting screw is in place and sticking down about 1/4". This helps align the upper spring perch.

4. Once assembled, unscrew the adjusting screw and remove the locking nut from the adjusting screw. Wrap the lower half of the threads of the adjusting screw with plenty of Teflon tape.

5. Screw the newly wrapped adjusting screw back into the BOV. Screw it in only a few turns.

6. Get a hand held vacuum pump with built in vacuum gauge. These can be rented or purchased from an auto parts store.

7. Attach the hose from the pump to the upper nipple of the BOV. Apply vacuum to the BOV by squeezing the pump. Continue pumping until you see the plunger of the valve BEGIN to lift off its seat. Note at what vacuum level this occurs by looking at the reading on the gauge built into the pump.

8. Our goal here is to have the valve BEGIN to lift off its seat at around 10 inHg of vacuum. For example, if it BEGINS to lift at 18 inHg, you will need to loosen the adjusting screw. If it lifts at 5 inHg, then you will need to tighten the adjusting screw.

9. If you cannot get the valve to BEGIN lifting at 10 inHg, don't worry......anywhere from 7 inHg to 15 Hg will be fine. 10 inHg is the target reading here.

10. Once you have adjusted the BOV and gotten the readings you want, tighten down the locknut. One last time, squeeze the pump several times and look at the gauge. It should hold vacuum for a long time and not leak down. The Teflon tape here is necessary. Without it, the valve WILL leak down every time.

11. This method is only valid for recirculated BOV applications, as the valve will be open at idle. If you are using your Type S as an atmospheric BOV, then you will need to tighten up the valve to be closed at idle. This means that the valve would BEGIN to open at about 23 inHG, depending on how much vacuum your engine creates.

Good luck to all,