Well, I finnaly installed my intercooler and BOV. The intercooler is a Greddy frount mount with piping, and I am using a mitsubishi 1G BOV.
Well here is my problem/question:
I took it out for a run and it pulls good, but when I let off the throttle after building boost, I can here the BOV open, but the turbo still vibrates. and it does it in a steady pulsing rythm. So I checked my vacuum lines ect…everything seems good, but it seems like it’s not opening up enough to let all the air out, or is opening and closing rapidly.
And, when I am in a high gear and hit full boost and hold it, the air starts pulsing. Like the boost pressure is fluctuating up and down. It’s sound like the boost is not steady, like it’s quickly building and falling. But I can’t re-create this while it’s parked so I can’t see if my BOV is venting pressure off.
I have never heard of the second problem, but I know the first is bad for the turbo. So what do I need to do to stop this??
Thanks for the help guys!
There is a ghetto way of checking to see if your BOV is working under load.
Duct tape a whistle, duck call, turkey call, whatever. Something you can hear clearly under the noise of the car and engine. Go for a run, sound silly, you know your BOV is working, don’t hear anything, start at the BOV. btw, if you try this, make sure it’s taped securely on.
What happened to me when I had this situation was the my plugs were gapped too large. The car stumbled slightly when I was WOT, thought hte BOV was blowing open.
Perhaps try checking your silicone hoses for small leaks and stuff?.
Well, I can tell the BOV is opening, I just don’t know if it’s opening up enough to let out all the pressure.
Also, I am running a stock T25 at 13psi with an apexi AVCR.
How do you guys route your vacuum lines? I have SO many lines that needed hooked up I wasn’t sure how to do it. I figured the BOV was the most important so I hooked that straight onto the large vacuum nipple on the throttle body. and everything else is split off of the small nipple. And I tried using the nipple on the bottom of the throttle body, but it didn’t work…what’s it for??
your problem is that your running more boost then the BOV can handle, I heard those BOV’s can only handel 10PSI before they start to open on there own. i would dial the boost down untill you can get a more reliable BOV like a Greddy, HKS or TurboSmart
That’s what I was told, so that’s why I am using it. 1G talons boost past 10psi stock don’t they?!! it wouldn’t leak that low! Sport compact car magazine did a comparison of a bunch of BOV’s and found the 1G BOV to be better than alot of high end expensive ones.
But I would like to try something else in good condition just to compare and see if the problem goes away or not.
Well, I just installed a greddy type-S BOV. it’s adjustable so I figured I could solve the problem. It is the kind that has 2 vacuum nipples, one for opening up the BOV with vacuum from the intake manifold, and one for helping open the BOV by connecting to your intercooler pipe to provide pressure on the under side of the internal BOV seal. helping it open, but also pushing it open if the spring is too loose.
Well, first I just hooked it up to the vacuum, and I have to set the spring really loose for it to open preperly and relieve the pressure. however with the spring that loose, it opens up at high RPM’s. so I stiffen up the spring and then it doesn’t open up enough when I let off the throttle. So I figured I need to hook up the second line to help the BOV open. well then when I pass 6000RPM it opens and the engine looses intake pressure and stumbles really bad. so I stiffen up the spring, but then it doesn’t open up when I let off the throttle very much. And I can’t find a happy medium where it will do both properly. so I am wondering what I need to do?? is it normal for it to open at high RPM’s, is the BOV not working properly, am I forgetting something? I replaced a bunch of vacuum lines just to make sure, and checked for leaks of vacuum and intake pressure. I took apart the BOV and cleaned it to make sure the seals weren’t clogged or something. I am just at a complete loss as to what to do now??
Please offer any suggestions.
Thanks
Hows ure idle when u set it soft, I had to recirc mine because it fucked with my MAF and ECU. Did simular things to what ures is doing right now, except it would hunt at idle and when id hit like 3400 rpm it would stumble(too much fuel im assuming). Once i recirculated it it ran wonderful, but it still doesn’t blow off at low boost. I was told on here that it should crack open at about 1-2 psi, but i don’t have a boost guage so im just guessing where to set it. Mine only has the one sense line as well, its an ARC unit.
On a side note, those brakes you sold me are S14’s not sr20’s. I brought the pads into Nissan to match them up and maxima’s are slightly bigger. So i just hope s14 4 bolt hubs are the same bolt pattern as s13’s.(if anyone can confirm this pls let me know)
for one, if you’re running a 1g mitsu BOV you should definitely re-circ, as its not a dual chamber, its more of a bypass valve. It should be opening fine at 10psi, they have been known to leak at 25psi + until you crush them.
the reason you’re stumbling when it is forced open is not-re-circing… you’re losing metered air and running pig rich. why its opening prematurely i have no idea!
yeah, i know about the re-circ thing. thanks. I was just wondering why it was opening and letting out my boost, not why it’s idling bad and stumbling when the BOV opens. I will be recircing it right away, I just needed something welded up first.
thanks though.
on another note:
I think i figured it out, it seems to be running good now. I’ll have to wait untill I recirc it before I will know for sure, but I think it’s OK now.
THanks for all the help