Greddy Type-S FYI...

[RuBiCaNT5X]

I hooked up the lower nipple of the Greddy Type-S bov to the (usually capped if you have a MBC) nipple off the compressor housing of the T25 and I have eliminated my BOV flutter at all boost levels... If you already know, sorry for wasting your time..

 

[KRAZYKOREAN]

The flutter is because its set to tight...all your doing is giving it more vacuum to it..which means its like your just adjusting the bov to softer...if you remove that line which you don't need and set your greddy softer you will not get flutter..thats why there that adjustment on top..

 

[RuBiCaNT5X]

Try again.. I had it as loose as can be and it does not help at all... Pressurizing the lower nipple is the only thing that helped...

 

[KRAZYKOREAN]

Try Again? I had the greddy type s and so did like 5 of my friends and if they fluttered they just adjusted softer and it was fine...but whatever..maybe yours is just wierd...

 

[igs]

That just means you needed it looser (take out one of the springs). You might be leaking boost now.

 

[candela]

IMO, I would have left it fluttering...
You should not ever unhook the upper nipple, nor hook up the lower nipple. Its not bad, its just that you are most likely leaking boost now and you dont even know it. I don;'t know whats wrong with a little fluttering... taking out one of the springs is also a bad idea as it definetly will leak at pretty much anything higher than 14psi.

this is from a reply of mine about 5 month's ago

In a nutshell, hardening/softening increase spring pressure to hold more/less boost without leaking. Your goal should be to not have compressor surge (which isnt very likely on most aftermarket BOV's) and to have NO leaks. I would not recommend taking out the spring o the greddy unit, if thats what you want then sell yours and buy a stock 1G bov.... Most aftermarket BOV's are capapble of holding 20+ psi pretty easily, but may a be a little to hard to haev the best of both worlds and let off 3psi of boost without surging a bit.... you can adapt to the way you drive so you dont surge

and this is directly from the greddy website

The lower fitting is a vent for the internal diaphragm. The lower nipple should be left open and not be connected to anything. Do not plug up this opening.

Trust me on this one...

 

[RuBiCaNT5X]

First off, I don't mean to piss in anyone's cereal. The fluttering was causing my TPS to go off with error P0120 as you may have seen on previous posts of mine, begging for help. Second of all, I do have a boost leak somewhere and I am 80% sure I have found the culprit. The valve cover is leaking in two spots on the left side in which case I need a new gasket. I did a leakdown test and that was it so far. Their might be more

There has been some talk on other threads on DSM Talk and on the Tuners about providing pressure on each nipple of the Greddy to eliminate fluttering. Some people have tapped the IC piping, another dood used the compressor housing nipple that usually gets blocked off. I tired it out and it worked. Dejon Tool sells a similar device for the 1G BOV as well as for the Greddy that pressurizes the top and bottom of the BOV upper membrane to prevent compressor surge and fluttering. I called them up on the phone and asked them if it worked the same with the lower nipple of the Greddy than with the 1G and they said the very same. Not to say that Dejon tool is the place to get all your info from and they are never wrong, but they know a helluva lot more bout this stuff than I do so why not.. What I did is similar to the product they sell, but I wanted to give it a shot with the same principle and see if it worked before I drop $50 on something I am not sure about. Again, say what you will, I'm keeping it on rather than chase phantom CEL for the rest of my DSM days.

Here is a pic.

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Here is a snippet off their site

"To seal we want no boost pressure under the BOV diaphragm until the TB closes - then we want full boost to open the valve. The solution is:
1-drill and tap a hole in the side of the BOV flange to intersect the small hole in the valve's flange bottom (which goes vertically to the underside of the diaphragm), insert a 1/8" hose fitting and seal the hole in the flange bottom with a 10-32 set screw.
2- now we have to switch the pressure to this fitting between atmospheric pressure when manifold pressure = boost, and boost pressure when manifold pressure drops. We do this with a small 3-way - pilot pressure operated valve, using the manifold pressure to operate the pilot. (activate the valve) It requires 15psi to switch. So with pilot (manifold) pressure less than 15psi the valve sends boost pressure (from a tap in the intercooler piping) to the underside of the diaphragm to operate it normally, and at boost over 15psi the valve switches, venting the diaphragm's underside and sealing the BOV. Leakage almost completely seals!"

 

[Bd1000Eclipse]

i tried it both ways and didnt notice a difference either way, so i did what greddy said, since they made the BOV and left it uncovered.. if it works better with pressure then do it.

 

[Lord Khan]

Here's my post from that other Greddy thread on the first page of this forum:

"I have mine connected and it works perfectly. With it hooked up, it helps to open the valve faster, and makes more of a louder sound. Although the Greddy Type-S gets rerouted back into the system, on my car it is extremely loud. I ran it with, and without the bottom nipple, and I found that with it hooked up, it was easier to adjust it and reduce the BOV sputter since this valve is very tight...even when it's adjusted to be loose. I'm running a stock T25 at about 14-15 PSI, and the Type-S is running perfectly. BTW, I have the bottom nipple hooked to the nipple that comes from the turbo.

After hooking up the MBC, my friend and I had blocked off the turbo nipple, but it even says in the Greddy Type-S instructions to route the lower nipple to the turbo nipple for faster/louder BOV response. Why it says it in the directions, but says otherwise on their website is beyond me. So I hooked mine up to it, and it works perfectly.

(Now if your running a bigger turbo, with higher boost, this connection is probably less necessary since more boost is going to open the valve faster anyway.)"


I'm starting to think that the reason there are so many conflicting views about this issue is cause people are running different turbos, and boost preassures which is causing confusion on the general hookup of the Type-S.

Bottom line, if your running a T25 on a second gen., hook up the bottom nipple cause the valve is too tight for low boost and needs the extra preassure, if your running either a 1st gen with a 14B, or a 1st or 2nd gen with bigger turbo's and higher boost, then the valve is already getting more preasure and doesn't need the bottom nipple. But like I said above, it says in the Type-S instructions to hook up the bottom nipple if you want quicker, louder BOV response.

Now this is just a theory, but I think I probably hit it right on the nose why there are conflicting information about that bottom nipple.

 

[candela]

Well you are sorta right...

You are however wrong about the t25, 14b thing. I dont want to get into this but a boost setting is still a boost setting regardless of turbo size. However the only reason I argue attaching the lower nipple is because in my experience (since Im sure we all will have different results ) with a few greddy units, attching the lower nipple will cause it to leak. Now yes it will react quicker and open a bit quicker as well causing a little bit louder vent, but there is a downside.

If you know what hooking up the lower nipple does then you should see how it can leak. It get rid of the flutter IMO, not from opening quicker, but from leaking a little bit. As soon as boost would go above about 4psi it would leak from the main vent and it was coming from the pressurizing of the lower part of the diaphragm from the lower nipple. For max performance, forget a little flutter, its taken to seriously....its not gonna hurt nothing, and you also want NO leaks period. Leaks kill efficiency of the turbo and combustion. So basically what im saying is that I still think Im right

 

[KRAZYKOREAN]

 

[RuBiCaNT5X]

Originally posted by candela
Well you are sorta right...

I can see how it makes the BOV leak because that nipple off the compressor housing is pushing out pressure all the time and thus forcing the BOV open sooner than one would want, however at lower boost 12 - 15 psi I'm not worried about leaking just yet. I was more happy with the fact that my CEL was not going off every other day. The ass dyno didn't pick up any difference in performance.. :laugh:

 

[SPEEDY]

Originally posted by candela
Well you are sorta right...

You are however wrong about the t25, 14b thing. I dont want to get into this but a boost setting is still a boost setting regardless of turbo size. However the only reason I argue attaching the lower nipple is because in my experience (since Im sure we all will have different results ) with a few greddy units, attching the lower nipple will cause it to leak. Now yes it will react quicker and open a bit quicker as well causing a little bit louder vent, but there is a downside.

If you know what hooking up the lower nipple does then you should see how it can leak. It get rid of the flutter IMO, not from opening quicker, but from leaking a little bit. As soon as boost would go above about 4psi it would leak from the main vent and it was coming from the pressurizing of the lower part of the diaphragm from the lower nipple. For max performance, forget a little flutter, its taken to seriously....its not gonna hurt nothing, and you also want NO leaks period. Leaks kill efficiency of the turbo and combustion. So basically what im saying is that I still think Im right

I agree 100% with candela. I get a little flutter between shifts. It's not much but some is noticeable. I have my GReddy Type-S set on the hard side with about three threads showing on the adjuster, and with the lower nipple unhooked. If your going to run high boost you are going to have to suffer with a little bit of flutter, or your going to leak, and lose performance. If I'm not mistaken.. I beleive the GReddy Type-S is suppose to have a little flutter anyways. I know there are many many more threads on this subject because I was wondering the same thing about 4 months ago and came to the conclusion that that's just the way it is. Feel free to Correct me if I'm wrong anywhere candela.