Alwright, getting a little frustrated with the Greddy Type-S on my new Turbo.

[Lord Khan]

I've already done the search, and I know people have talked about this before, but I still haven't seen a definate answer. I have been using the bottom nipple of the Type-S to the bottom nipple of my T-25 since I got it to make the BOV open easier. But their is still a big debate of whether this causes a boost leak or not.

So I've had my FP-BigT28 for a couple of weeks now, and decided to take that bottom connection off the nipple since this is a stronger Turbo, and shouldn't need help to push the valve open. Well, let me say first of all that as soon as I did this, my boost guage started going a pound higher from 15 to 16. Maybe it was causing a leak? Anyway, the main problem is that I can't get this thing to stop compressor surging the turbo when I ease my foot off the gas in normal driving. I keep loosening the BOV but it doesn't seem to help much. If I take my foot off quickly, it makes the famous "chirp", then blowoff sound normally, but when I ease off the gas if I just want to slow down, or ease of the throttle, you hear violent compressor surge stutter from the BOV. It sounds a bit like "cha-cha-cha-cha-cha" with no blowoff at all.

Is this damaging the turbo? Sometimes it happens at low boost which is expected, but when I'm boosting to 10-12 lbs, and just ease my foot off a bit, it stutters completely.

Should I put that bottom hose back on? I'd rather have a slight boost leak, than destroy my BRAND NEW Big-T28 from some lousy compressor surge over an extended period of time.

 

[Red97Eclipseboy]

http://www.dsmtuners.com/forums/showthread.php?t=125894&highlight=greddy+type This should help.

 

[Lord Khan]

Yeah, I've read through that thread, and a bunch of other ones before. I was just wondering if anyone has any proof of the valve leaking when the bottom nipple is connected. The BOV works perfectly when I have it connected and I don't get any surging whatsoever. It even says in the intructions of the type-S to hook up that nipple to help the valve open faster, but then people posted the link to Greddy's website here stating to keep it off. I'm starting to think that it all depends on what kind of car you have, turbo, and setup. Cause it seems everyone on here has issues with this thing when the bottom nipple is left open.

 

[TD05HTalon]

The small nipple on the BOV does not cause it to leak boost. I have my Type S venting to the atmosphere because i'm using the MAFT in blow through. The valve definitely does not leak boost. The small nipple just helps the valve open faster by preloading it with pressure so when you let off the throttle the spring opens faster. This is a good thing because it prevents the air bouncing off your throttle body from traveling as far backwards in the pipes. I have the small nipple sourced from my lower ICP with my big 16g and no problems. I say that if there's a 2nd nipple on the BOV it was put there for a reason so use it - the Greddy engineers probably know what they are doing.

 

[Red97Eclipseboy]

I guess you're supposed to leave it unhooked for your application. If you're worried about it, just go buy some of those little nipple covers at the hardware store and call it a day. I had to use one on my budsdies SRT-4 when we put his RFL on. You have to cut inot the intercooler pipes along the bottom of the car to put the new BOV in. Then, plug the old BOV with the fittings I mentioned. They work.

 

[Lord Khan]

I'm about to go to lunch now, and I'm going to put it back on. I've never had any problems with it connected, and it blows off properly when it is set that way. Only reason I thought otherwise is from the massive debates on this forum about it. Thanks for the help guys.

 

[hostile]

First thing first, boost doesnt open the valve, vaccume does.

If you have a lot of volume in the intercooler pipes, but vaccume on the other side of the manifold the valve is going to open and close. This isn't compressor surge. It is BOV flutter. It wont hurt anything.

Just hook up the top nipple, then leave the bottom one disconnected. Then adjust it towards the middle of hard and soft.

 

[anumeric]

I only skimmed through what you wall said but you should NOT leave the bottom vacuum nipple unhooked. It assists the bov in opening faster and at lower psi's which means you can have a harder setting without the flutter. harder setting=less leak...no worries

 

[Lord Khan]

I put it back on the other day, and tightened down the BOV to about 5 or 6 threads high. No boost leaks, and no stutter at all. Well mabey an occasional stutter at 1 psi but thats about it. This BOV makes substantially different blow offs depending on how it is hooked up.

 

[anumeric]

back off on the screw a 1/2 turn

 

[RAVAGER576]

I have tried both ways with mine also and I have to say that I DO get a major boost leak with the lower hooked up ... But I also do get the surge associated problem too without it hooked up ... But my question is ... Is it REALLY doing that much bad with the ch-ch-ch at low rpms? I mean think about it the turbo is not even spooling that strong so its not like even if it was causing surge it would be doing any harm ... Correct me if Im wrong but the only harm seems to be the spooling would be a tiny bit slower into next gear but if you shift quick that probably wouldn't even happen. Am I wrong??

 

[anumeric]

I have tried both ways with mine also and I have to say that I DO get a major boost leak with the lower hooked up ... But I also do get the surge associated problem too without it hooked up ... But my question is ... Is it REALLY doing that much bad with the ch-ch-ch at low rpms? I mean think about it the turbo is not even spooling that strong so its not like even if it was causing surge it would be doing any harm ... Correct me if Im wrong but the only harm seems to be the spooling would be a tiny bit slower into next gear but if you shift quick that probably wouldn't even happen. Am I wrong??

ch ch ch=flutter? or do u hear the bov sound off multiple times? if it has the hight pitched noise a bunch of times your setting is too soft...i would assume that a little flutter isn't that bad since the hks ssq will always flutter no matter what...i don't know how you are getting major boost leak with the second vacuum hooked up.

 

[McGruffAWD]

The small nipple on the BOV does not cause it to leak boost. I have my Type S venting to the atmosphere because i'm using the MAFT in blow through. The valve definitely does not leak boost. The small nipple just helps the valve open faster by preloading it with pressure so when you let off the throttle the spring opens faster. This is a good thing because it prevents the air bouncing off your throttle body from traveling as far backwards in the pipes. I have the small nipple sourced from my lower ICP with my big 16g and no problems. I say that if there's a 2nd nipple on the BOV it was put there for a reason so use it - the Greddy engineers probably know what they are doing.

Right...that is why in the manual when it tells you how to hook it up..it says leave the bottom nipple unpluged...

 

[Lord Khan]

"Right...that is why in the manual when it tells you how to hook it up..it says leave the bottom nipple unpluged..."


The manual mine came with said to hook it up if you want the BOV to open easier. It said nothing about leaving it unplugged. But apparently there was something on their website at one time saying to leave it unplugged which contradicts the instructions which = confusion. But from personal experience, the valve doesn't seem to blow off properly in normal driving (ease your foot off the pedal in traffic) without causing serious stutter, even at the softest setting. Yet when you hook up the bottom nipple, you get a smooth blow off when you adjust the screw accordingly.

 

[anumeric]

"Right...that is why in the manual when it tells you how to hook it up..it says leave the bottom nipple unpluged..."


The manual mine came with said to hook it up if you want the BOV to open easier. It said nothing about leaving it unplugged. But apparently there was something on their website at one time saying to leave it unplugged which contradicts the instructions which = confusion. But from personal experience, the valve doesn't seem to blow off properly in normal driving (ease your foot off the pedal in traffic) without causing serious stutter, even at the softest setting. Yet when you hook up the bottom nipple, you get a smooth blow off when you adjust the screw accordingly.

if you have an understanding of how it works...we can safely say ^%$#@ the manual and burn that %$#@ to hell =)

 

[anumeric]

don't take MY word for it...

http://www.dsmlink.com/forums/showthread.php?s=&threadid=786

 

[anumeric]

in fact...do a boost leak test w/ out the bottom nipple open and the screw set so it doesn't flutter...it will leak from the screw...do the same w/ the nipple hooked up!

 

[WSU99GSX]

Hmm so it really depends on your vehicle huh, sorry to bring this back from the dead, but I have been ready alot about this subject. Seems that with the lower nipple hooked up the BOV opens faster for people but they seem to loose a pound of boost, with it open people get back surging and bucking. Any new ideas from all of you who have posted on this one?

 

[DSMeclipse4G63]

if you need help hooking it up Ill show you my setup, and I have no surge at all. Let me know
Andrew

 

[Lord Khan]

Hmm so it really depends on your vehicle huh, sorry to bring this back from the dead, but I have been ready alot about this subject. Seems that with the lower nipple hooked up the BOV opens faster for people but they seem to loose a pound of boost, with it open people get back surging and bucking. Any new ideas from all of you who have posted on this one?

This is definately the case with my car. But the loss of the pound of boost is fixed by just turning up the boost by the boost controller. I guess they just make it so you can hook it up how you like. To me though, it works like a bov is supposed to work with the bottom nipple hooked up. From everything I've read, a bov is supposed to make a smooth blow off, and not stutter what so ever (maybe at extremely low boost, but that is all). Like I said, I put it back on, with it running to that bottom nipple on my T28 and it works fine. No leaks.

Had a few nice races on the way back from Nopi Race Wars here in Maryland this weekend. Car drives fine with the thing on.

 

[WSU99GSX]

Okay thanks, I am going to be hooking up mine soon, just wanted to make sure I had the facts straight.

 

[anumeric]

that's funny...w/ the lower nipple hooked up i got 4 psi more (9 to 13) but originally my piping for the 16g had no boost source so a nipple was tapped into the licp and i'm my stock boost controller is still capped off

 

[GSXeclipsePSI]

Ok... I'm buying a Big16G today online. So I should cap off my nipple on my greddy? or should I connect it to my 16G? ... Give me a picture... or something.. I'm confused on what the GENRAL answer is!

 

[Lord Khan]

Ok... I'm buying a Big16G today online. So I should cap off my nipple on my greddy? or should I connect it to my 16G? ... Give me a picture... or something.. I'm confused on what the GENRAL answer is!

No, no, you don't want to cap off the Greddy. Either leave it open, or plug it to a nipple on your 16G (can't tell you which one as I'm not familiar with the 16G). I have a T28 that is the same housing as the T25, and I hooked it to the nipple that is under the wastegate actuators nipple. I have the wastegate actuators nipple hooked to my boost controller.

 

[bTIDDY]

All you have to do is hook up the top fitting and cap the lower nipple. Pull the screw all the way out and it will hold as much boost as you give it.