whteteg8901

the bov fluttered in almost any driving condition now i adjusted it so its as loose as possible. Now you can hear slight fluttering under low boost. At 7-8psi it doesnt. Is this typical for a type-s bov?

tia

splitime

Simple way to soften it is to pop it open and remove one of the springs. For higher boost... you'll want to keep that spring though.

I almost forgot! Run a boost source to the 2ndary input... that helps a bunch on bov reaction time.


Modified by splitime at 2:52 PM 2/8/2006

igo4bmx

i've taken mine apart and cleaned it, then gave it a strong source of vacuum which helps.

boostincoupe

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by igo4bmx &raquo;</TD></TR><TR><TD CLASS="quote">i've taken mine apart and cleaned it, then gave it a strong source of vacuum which helps.</TD></TR></TABLE>

Now let's discuss this.

Most of the threads I've read tell people to leave the lower nipple exposed to the atmosphere.

You're saying that it's BETTER for the BOV's lower nipple to be connected to a vacuum source?

splitime

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by boostincoupe &raquo;</TD></TR><TR><TD CLASS="quote">Now let's discuss this.

Most of the threads I've read tell people to leave the lower nipple exposed to the atmosphere.

You're saying that it's BETTER for the BOV's lower nipple to be connected to a vacuum source? </TD></TR></TABLE>

Put the top to a source AFTER TB... and the bottom a source between turbo and TB.

tallyturbo

if you not planning on running high boost upen it up and take out on of the springs and then try adjusting the screw

Rufus523

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by igo4bmx &raquo;</TD></TR><TR><TD CLASS="quote">i've taken mine apart and cleaned it, then gave it a strong source of vacuum which helps.</TD></TR></TABLE>

Sounds right.

Mine started to flutter a while ago. I just took it apart, cleaned it, put it back together, and gave it a dedicated vacuum source (front of the intake mani, big nipple ).

It works fine now. I never bothered to route the other vac source. Just left it open.....

igo4bmx

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rufus523 &raquo;</TD></TR><TR><TD CLASS="quote">Sounds right.

Mine started to flutter a while ago. I just took it apart, cleaned it, put it back together, and gave it a dedicated vacuum source (front of the intake mani, big nipple ).

It works fine now. I never bothered to route the other vac source. Just left it open..... </TD></TR></TABLE>

i tied it into the brake booster line and that helped

rioninja

Be careful hooking the bottom port to a boost source. The valve is not sealed on the bottom, so you will end up with a tiny boost leak by running a line to it.

redzcstandardhatch

i never noticed any problem doing that. didnt loose any boost or anything. . it is a VERY smalle hole.

its purpose is to assist in opening the valve quicker. it works well. i have mine this way, works great. pops open IMMEDIATELY now.. really quick, loud, and sharp. pretty cool.

Stylinhonda

Hmm I might have too hook up both on my type S. My friend said something about the diaphrams on type s going bad? Know anything about this?

whteteg8901

i opened up the bov yesterday to see whats the problem and one section of the rubber thing inside (i guess the diaphram) looks like its melted together . ill take it off again to take pics.

Silverbullet86

bottom nipple does nothing. I dont even know why its there. Do not hook it up to a vac source, not that it would do anything. The bottom nipple does not goto the same chamber as the top nipple. The top nipple leads to the pressure chamber that actuates the piston. The bottom nipple is in the same chamber were the air is vented... so basicly if u hook it up, it will not do anything at all.

I've never heard of a Type-S fluttering. I did not think it was possible and i still dont from it's design. It's acutally a really poor design. I think what your hearing is compressor stall from the turbo. You either have the BOV adjusted way too tight, or your not getting a good vac source.

Hybrid96EK

I'm beginning to wonder if having the bottom port hooked up on my Type S is the reason why boost seems to fall off slowly until around 3psi at redline..

Silverbullet86

nah, not likely... sure ur gauge is accurate?

Small turbos drop boost pressure when it gets close to red line, but until 3psi... jesus.

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Silverbullet86 &raquo;</TD></TR><TR><TD CLASS="quote">nah, not likely... sure ur gauge is accurate?

Small turbos drop boost pressure when it gets close to red line, but until 3psi... jesus.</TD></TR></TABLE>

I'm running the 19T turbo, its not a behemoth or anything, but not THAT small either that it should be dropping that much. Gauge should be accurate, its consistant with what I show in the datalogs.

HiProfile

You don't hear of the type-s seal going bad much around here, mainly because most people run under 15psi. Older supras/etc that would run these apparently have problems when they keep the boost cranked for a while, gets to be tough on that rubber.

I'm going to guess this will be the main issue that the type-s copies will run into in the future, and IIRC the rubber costs $60 from greddy alone.


As for the upper/lower nipple: they act upon opposite sides of the rubber seal inside. Vacuum sucks the valve up, and if you push it open at the same time from below, it opens faster. While the TB is open, both sides see the same boost pressue, and the spring is what keeps the valve closed. When the TB slaps shut, the top turns into a vacuum while the lower half stays pressurized - until the charge pipes depressurize.

Hybrid96EK

Well, I went out to test things and disconnected the lower hose on the BOV (hooked directly up to the top charge pipe) and left the top hose hooked up to manifold vac. Amazingly, no more boost falling off. I still have an issue with the boost controller of spiking and then it levels off, but I am no longer loosing boost. After thinking about it, it actually makes sense. I mean, the bottom port with boost would tend to try to push the diaphram open. The top port obviously under boost would try to push the diaphram closed, so you would THINK they would cancel each other out, right? Well, think of this too. You also have the pressure pushing on the piston of the BOV trying to open it. I am assuming this is the reason why it was causing a boost leak in my sistuation. I had tried previously to adjust the BOV with no success.. once that line was off, problem was resolved. Just thought I would update.

splitime

Interesting.

I know that when I ran both sources for the first time, I also put my 2nd spring back in. I don't get any boost drop off... and the reaction time for the BOV (with both ports hooked up properly) was MUCH faster than before... and wouldn't have issues opening at lower PSI.

My problem was that at lower psi I would get compressor surge with the 2 springs in, despite adjusting... 1 spring fixed that... but with higher boost, I found that 1 spring wasn't enough... so I ran both sources, put 2nd spring back in and boom... bov functions at low/hi boost and reaction time was vastly different.

You guys have real Greddy bovs right? Not e-bay specials, I'm just wondering if there is something different in the setups to be causing different results.

Hybrid96EK

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by splitime &raquo;</TD></TR><TR><TD CLASS="quote">Interesting.

I know that when I ran both sources for the first time, I also put my 2nd spring back in. I don't get any boost drop off... and the reaction time for the BOV (with both ports hooked up properly) was MUCH faster than before... and wouldn't have issues opening at lower PSI.

My problem was that at lower psi I would get compressor surge with the 2 springs in, despite adjusting... 1 spring fixed that... but with higher boost, I found that 1 spring wasn't enough... so I ran both sources, put 2nd spring back in and boom... bov functions at low/hi boost and reaction time was vastly different.

You guys have real Greddy bovs right? Not e-bay specials, I'm just wondering if there is something different in the setups to be causing different results.</TD></TR></TABLE>

It is without a doubt a genuine Greddy Type S BOV. I got it brand new, in the box.

rioninja

The reason the bottom port leaks, is because the valve is not sealed.
the air pushes against the diaphram on the bottom, but at the same time it leaks past the valve "stem" inside the bov. If you put a hose on it and blow, you can hear how much is leaking past.