BOV problem?

[mazdaspeed32007]

probably from about early december whenever i creap into boost from -2 vac into low psi range i get what sounds like a whistle. the gauge reads very unsteady boost and all of a sudden if i creap the gas in just enough it snaps into about 5 psi boost. all my numbers according to my ap are fine and WOT the s*** flys with no problem. im assuming it was the bov leaking like it didnt close all the way and then somehow the right amount of pressure was enough the close it allowing for boost to build. ive ripped it all apart and it seems alright. seals are fine, regreased it and everything. im going to move to VTA soon because the positioning of the BOV for the FMIC is kinking the recirculation hose....not totally, but about half the volume of air isnt getting through. any ideas? ive also taken apart the whole intake system and FMIC and rebuilt it thiniking i had a small leak somewhere but no such luck.

 

[mazdaspeed32007]

so ima post a video of the sounds. its a cellphone video so it kinda sucks but u can hear it.

http://www.youtube.com/watch?v=qqL3D60DNyc

 

[MSMS3]

im going to move to VTA soon because the positioning of the BOV for the FMIC is kinking the recirculation hose....not totally, but about half the volume of air isnt getting through. any ideas?

Going VTA will just make your problem worse. Try this: Put your stock BPV back on and see if your problem is solved. If it is, as I suspect, either adjust the positioning of your aftermarket BPV and hose so they fit correctly, or get another more flexible hose, or better yet, just run the stock BPV. It holds boost well and lets the engine make great power. I'm spiking to 21 and quickly returning to and holding 17-18 psi right up to the shift point. Whatever you do, run full recirc. With your mods you should know that.

VTA is not good for this engine. Period. It will just run worse, your AFR will be wrong, your ECU will be driving itself crazy trying to yo-yo to compensate and eventually detune. AP wants you to run the stock BPV and to run recirc. All their maps are based on this and for good reason. You really can't custom tune around it either without moving the MAF sensor. All the while you will be farting already metered oxygen to air that your engine thinks and knows it should be matching with fuel to produce power. This is a MAF engine. It needs to keep the air it has already metered and matched fuel with going back into the manifold so it can get where the ECU is telling it to go - out of the manifold into the engine to match the corresponding fuel charge from your injectors.

Whatever your problem is, VTA is not gonna make your engine run better. Test with your stock BPV to see if the BPV is really the problem and go from there.

 

[mazdaspeed32007]

sounds good msm. i have some numbers written up in a-tuner that tune out recirc but as you ststed you cant really do it without repositioning the MAF. besides that, im not sure if i could locate my stock bpv but i already have a friend coming next week with his greddy so we can swap it out from his speed6 to see if the problem is solved. if thats the case i think im either going to be buying a new bpv or see if someone else can figure the thing out. iv tried an endless spring and shim combo to try to fix it and it has been dismantled and regreased 3 times to attempt to fix it. all of the o-rings seem in working order...i clean and regrease it several times a year and its bolted nice and solid to that throttle body pipe. idk...i guess one step at a time. ill repost next weekend when we swap it out. until then, no boost.

the car, before the problem, had no spike issues at all. i had a few custom tweaks in atr where boost would shoot to 19 and not budge. i just cant remember if i ever heard this as soon as i switched to the front mount. if thats the case it very wellcould just be the recirc hose right? im going to buy another hose tomorrow sometime so the fitment it correct. thanks again for now msm.