i can change the sound of my greddy type s by the vacuum hose that connects to it...just wonder if anyone else has done it?? kinda cool

 

what boost range can that BOV handle?

 

i dunno..i have put my boost over 20 psi before but i think the bov leaked when i put it that high and made my ic piping come off. so i dunno and it has nothin to do with the screw on top either

 

OMG....OK the screw on top adjust the BOV. There are two springs in there that sit under a large washer that, when you tighten the screw, smashes the springs making it harder for the valve to open and vent the extra pressure. As far as the amount of boost, I've heard of people running 25psi on the Greddy Type-S...I wouldn't push it much more than that though.

And what vacuum line are you talking about, I have a Greddy and you hook the intake line up to the top nipple and that's it. What are you talking about????

 

i've heard, seen, and witnessed people running well over 25 psi on a greddy type s, with no problems AT ALL....that is all

 

the Type-S is a great CBV.. great sound, dischages plent of air, and easily adjustable.. just dont TURN THE NUT to adjust it... ive seen too many ill-informed people who turn the nut trying to adjust the spring tension only strip out the threads on the housing that hold the stud. the nut is the lock nut, you back it off. then turn the stud w/ an allen wrench in the direction you desire, according to the sticker on the top. harder means it puts more tension on the spring, and itll stay closed longer under higher boost. you can even adjust the CBV to stay closed at idle, like a H-K-Dollar sign SSQV. It also changes the sound.

itll hold more boost than your engine can safely run... lets leave it at that

oh, btw, the top nipple is the one you use for the Vaccum signal, it places a vaccum on the top side of the diphragm. since the Type-S is a pull-type valve, when the vaccum is high enough to overcome the spring pressure, it sucks the diaphragm up, and then the rod, and the valve attached to the end of it. this opens the CBV and allows air to discharge back into the intake. the BOTTOM nipple is not supposed to be used, since its BELOW the diphraghm. when your engine is not boosting, it would create a vaccum BELOW the diaphragm, and try to pull it down, which would force the rod connected to the valve down, and hold it shut under vaccum, which is BAD. when you shift, your engine sees Peak vaccum, and if the CBV sees it, the valve will stay closed and youll surge. The bottom nipple is SUPPOSED to just be a vent, so the air under the diaphragm can circulate in and out as the Diaphragm moves up and down when you shift. if it was sealed, the diaphragm wouldnt be able to move, just like if you leave the cap on your 20oz Dew bottle, you cant squeeze it, but if you take the cap off, you can squeeze it cuz the air is able to vent out the top. know what i mean?

 

The problem with setting it lick this is compresor surge. I know that on a t-25 if it doesn't vent at idle you will get mad surge at low boost levels. I have hooked up a boost gauge to the vacuum line and when you are on the throttle it actually puts pressure on the diaphram. So the way mine is set up right now, is that it's open at idle, as soon as I step on the gas it slams shut ans holds the boost until I let off the gas and the pressure changes to a vacuum and opens the valve....did that make sence to anyone but me???

 

that sounds retarded... are you saying that if your CBV doesnt vent at Idle and low boost levels, youll get surge??? tahts 100% wrong. see, the nature of a CBV/BOV is to open when under vaccum. At idle, your engine produces vaccum, which normally would make the CBV open. But, you dont need/want it to vent at idle. its not something you should be Shooting for or get all upset like "Godammit, why isnt my BOV venting at idle?! mother fucker!". The amount of vaccum at idle is ALWAYS less than the amount of vaccum during engine decerlation (during a shift, engine RPM's dropping when clutching, or deceleration in gear). If you are good/smart, youd fine tune your CBV to be open at maximum vaccum, but be closed at idle vaccum. a WELL tuned CBV will be closed at idle and open during max vaccum, IE: shifting, coasting in gear, clutching. the reason why MOST CBV's do vent at idle as it stands now, is because every motor has a different vaccum level at idle... some cars, its 20 in/hg, other cars its only 18in/hg. so a car that has a CBV that vents at 18 in/hg, and IDLES at 18 in/hg will be venting... id suggest tuning the spring tension a little tigheter so its closed at 18 in/hg, but opens @ 19-20 in/hg. that way, anytime the throttle is closed and the engine RPM's are anywhere above idle-speed, the CBV will be open cuz the vaccum is greater than normal Idle vaccum.

thats just my impression.

 

dang this is shitty for me then cus my idle vac. press. is at like 12 and my screw nut thingy on top of my bov busted off leaving me with a leaking broken bov....i didnt do this.. seriously... so anyhow.. i jammed a screw in the and it isnt even the right size. It is oversized but stays in at 20+ psi levels anyway is this bad if vac is that low pleae help me

 

what did you jam a screw into? the vaccum hose or what?

what is at 12? the vaccum or the boost?