Is your bov a tial by any chance ? If so I used to get this on the Z when I ran to heavy of a spring. If I remember correctly Tial suggest spring sizes based on what vacuum you are pulling not psi of boost. Its been a while since I researched it but needless to say I lowered to a 7 psi spring and it worked perfect.

Only other issue I ran into was to light of a spring and it would leave the bov open all the time.

The springs are cheap so its worth a shot.

 

The BOV is a Tial. I'll have to order another spring then and see if that solves the problem. When I got the car, the Tial was already on there and someone had put 2 springs inside the BOV. One is the Tial 10lb spring, but the other one is a little wider of a coil and a touch shorter. I ran that one by itself, but the BOV was open at idle, so its significantly weaker. I'll try a 7psi spring. Thanks for the help.

 

The BOV is a Tial. I'll have to order another spring then and see if that solves the problem. When I got the car, the Tial was already on there and someone had put 2 springs inside the BOV. One is the Tial 10lb spring, but the other one is a little wider of a coil and a touch shorter. I ran that one by itself, but the BOV was open at idle, so its significantly weaker. I'll try a 7psi spring. Thanks for the help.

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Thats how I have mine set. Just barely cracked open at idle. As soon as I touch gas peddle, it closes. You get better response with it like that.

The flutter on decel isn't really hard on the turbo, plus it sounds kinda nice.

 

Try the next spring down. I had the same issue, the "proper" spring based on my idle vac was too strong, so I used the next one down. Its cracked at idle.

Also, make sure that the BOV is the only line T'd in to where ever you are T'ing in (dont run your BOV and Boost gauge off the same line). I guess the reason the recommended spring doesn't work properly is because we are not tapping directly into the manifold for a dedicated line, but I don't think anyone has tapped a new port into their manifold yet.

 

So I swapped the lighter spring in, BOV is open about halfway under idle as before. I drove it around the block and it opens incredibly easy, a little too easy I think, but its very quiet. The surge is still there, just as prevalent as it is with the stiffer spring. I update the original post with a couple of (not so great) videos and some images on my routing. I am running the boost gauge off the same line as the BOV, but this was all in place when I bought the car, unfortunately.

I have an empty port on the IM that is nippled off and the moment. Should I run the boost gauge directly off the IM?

EDIT: or better yet, run the BOV off that port, as a dedicated line, and leave the existing line to run between the manifold and the MBC with the boost gauge T'd off?

 

Post pictures of your setup please. There was a huge reaction time difference when I removed the BOV and gauge line sharing bit.

 

pictures and video added to the original post. I just made another couple of videos that exemplify the sound way better. Uploading them now.

 

From all of my research, it sounds like I'm getting "compressor stall" not compressor surge. Like Rpecwhite mentioned, most people seem to be of the opinion that this doesnt really hurt the turbo. Its really freaking loud though, and I'd like to tone it down some. The gt3071r I just put in the car has a much larger compressor housing than the exhaust housing, so I wonder if that could have something to do with it? Maybe I need to examine the wastegate again? I'm at a loss here. I've got some hose coming in the mail to dress up the engine bay, so when I get that, I'll probably put the BOV on a dedicated line off the IM and see how that works out.

 

Wait, do you have the green and white check valve going first to your boost gauge, then to your BOV, and then to your MBC? Thats a horrible setup.

For your boost gauge, t into the old green and white check valve, and have it run back into where it usually would.

For your BOV, tap into the bigger line which is next to the brake booster, like this:

For your MBC, for boost reference tap into the nipple off of the turbo's compressor housing, if it doesn't have one probably better to add it to your intercooler piping right after the turbo.

 

You. Yeah, you. If you lived near me, I'd buy you a beer. I hadnt had the chance to try teeing off the line you suggested yet, as I couldnt find a damn tee that would work. Found one today, tee'd in to the hose, took her for a spin, zero compressor stall. Thanks man, you were a huge help.

 

The check valve was removed. In reference to the picture you posted, the right side of the check valve is capped off with a nipple. The left side is what the boost gauge, BOV, and MBC are all connected to.

Do you know offhand what size that larger hose is? I'll have some time this evening to work on it, so I'll swing by the parts store and pick up a T for it to route the BOV.

 

Thumbs what spring did you have?..ive tried unpainted and white, T into that same thick line and still get some flutter

 

I actually still get surge, a lot of it. I thought I had cured it, but I didn't. I've isolated my problem down to rev hang and the fact that our cars just don't have an awesome, dedicated vacuum source. Once I get tuned at the end of April, I think I'll see much better performance. If not, I'll probably buy a synapse BOV.

Edit: also, I have tried the plain and white springs. White is too weak. I'm running 19-20 lbs of vac at idle.

 

Well in some other thread about this issue, i saw a guy who bought a p2r throttle body spacer, which essentially adds teo direct vacuum sources from the manifold. Im gona look into it and most likely get it, im tired of this ****

 

Do you have a reflash that eliminates rev hang?

 

As soon as I saw your pictures, I thought to myself...where is his check valve and why is there nothing connected to that side of the vacuum... But its been covered.

 

Prw stage2 , which im pretty sure does. I only have minor flutter but at almost all psi's . I sure if i go with the -6 spring it will go away, but if the throttle spacer is not too expensive ill probably go eith that

 

Hmm, prw tunes should eliminate the rev hang. I spoke to Bill and he did mention that. What is your idle vac? I feel like this is such a common issue with the TiAL BOVs on our cars. I've read more than a few threads here with people complaining about surge. I just picked up some metal tees for all of my lines, so I'm going to swap those in tomorrow and I might throw the white spring back in and take the car for an extended drive to see how it runs. I have already boost leak tested the system, and all is good there.

With the plain spring (rated for my vac pressure), the BOV sounds fantastic. It opens just fine, just a tad late, causing the flutterdump back to the turbo. My turbo is a Garrett ball bearing, and I have heard that ball bearing turbos should be able to handle that deceleration surge way better than journal bearing turbos, because you don't have to worry about the bearing coming in contact with the compressor housing when the surge hits it.

When I drive the car, if I slowly let off the throttle a bit before fully releasing it, I can usually get rid of the surge. Also, if I am in full boost, above about 4500 rpms, I can let off quickly with little to no surge.

Let me know if you manage to eliminate the surge with the spacer. The surge makes the car sound so much more aggressive, but at the same time, I feel like it'll cause long term damage. I don't feel like rebuilding the damn turbo.

 

Let me know how that goes for you. Yes i have read that flutter on descceleration isnot that bad but ill rather have a fully functional bov with no flutter, and anyways with stock turbo im sure it hurts it over time. I can eliminate the flutter as well if i lift my foot off the throttle a bit. Anyways il let you know what i do man

 

White spring in. I drove it for about 10 minutes and was really able to open it up, do a few pulls, etc. the surge is almost non existent, so long as I let off the throttle quickly and don't feather it. I still get a little bit though, but it doesnt last as long before the blow off. The BOV is a bit quieter now too. Previously, it would have these very nice, beautiful sounding blow offs that lasted longer than they do now with the white spring. It went from a "psshhhh" at times to an "ush" sound, kinda like a sigh more than anything. I don't like it nearly as much, but most of the surge is gone, so I'll leave it in and continue to pay attention to it.

 

op your hose setup makes for a sad panda.

 

lol

 

you bought the car modded like that?

 

I bought the car with most of the mods you see in my sig, only there was a gt2871 in the car. The turbo turned out to have a damaged impeller, so I put the 3071 in. The car was purchased at auction, so I knew nothing about the mods aside from what I could see. I took a gamble and it bit me a little. Still, after the new turbo, the total I paid is about what a stock car with my mileage runs. I have had to do several little things, and the Exedy feels like its slipping in 4th, so I have more work to do.

 

I seriously hope whom ever did the original hose hookups isn't on this forum because I would have words for them.

Your stock solenoids all have to be correctly hooked up, only the outputs can have caps on them. In your first picture the vacuum tank has been taken out of the equation, meaning most likely the solenoid isn't getting the right signal and it can play havoc with your timing.
You don't have to use the stock solenoid to run your BOV, but have it at least bypassed correctly.
Unless, are you using a Haltech or stock ecu?

 

to add:
on the stock setup, it's made to "store" vacuum. that is why there is that green and white check valve on top of the intake manifold, which goes to a tank thats integrated with the IM and then from the tank, goes to the solenoids.
If you just bypass the solenoid, the bov won't open properly, because there won't as much vacuum to open it. the take store somewhere like 15~25 psi of vacuum regularly.

No haltech. I'm actually planning on hooking up the stock solenoid to because the MBC just brings on the boost too fast. I want to track the car in August on a road course, so I need something that's no so on/off with the boost. I haven't looked at how to route the hoses yet, but I should probably do that.

losen up the tension on the wastegate.

 

No haltech. I'm actually planning on hooking up the stock solenoid to because the MBC just brings on the boost too fast. I want to track the car in August on a road course, so I need something that's no so on/off with the boost. I haven't looked at how to route the hoses yet, but I should probably do that.

 

+1 to AKGC

 

I'm running an EWG, so no adjustments to be done. As far as the hose routing for the stock solenoid goes, do you guys have a reference picture by chance or can you give me a quick explanation about which ports are which on the solenoid?

I don't have the green and white check valve, as the previous owner removed it and capped off the IM port without vacuum. The other end is used to run my boost gauge and MBC. Should I look in to getting one, and just tee in to the line or does it not really matter?

 

Ok, so I connected the stock wastegate solenoid, and I'm playing with the boost duty cycles on the CMD. When I set the duty cycles to 20 or 25 at 90 and 100% throttle, I only get 7lbs of boost. If I crank the duty cycles up to 50, I get about 10lbs of boost, but I also get this incredibly annoying and very prevalent wastegate flutter as the boost builds, and my boost gauge looks like Michael J Fox is moving the needle. It literally sounds like the wastegate is stuttering open and closed as the car builds boost. I made a video, but its kinda hard to hear the noise. It started raining, so I went ahead and called it a day. Also, just for shits and giggles, I upped the duty cycle to 100 and the car overboosted up to about 25 PSI (before I let the throttle off to stop it) with the same crazy wastegate stutter.

For the connection to the WG solenoid, I connected the vac line from my TiAL EWG to the to top port on the left most solenoid, then I ran a hose from the back of the solenoid to the vac rail that runs in front of then engine. That vac rail gets its source from the location that the green check valve was originally. Before you ask, yes, I an running it on the side with the vac, not the side closest to the firewall. I also have my boost gauge teed in to that line.

Any suggestions?

Also, do I need to do anything in particular to bypass the BPV solenoid? Right now, it just simply not connected to anything, as far as vac lines.


Here are a couple pics of the current routing:

Solenoids. Again, only the left one is connected. View the second image larger so you can see the labels.

 

move the vacuum source line, from the tube to the front of the second solenoid.

take off the other end and put a T on it.

put one end of the T on the back of the first solenoid.

the last end of the T goes to the boost source, on the compressor housing.

Top of the second solenoid goes to the BOV.

Back of the second solenoid, goes to the vacuum source, the tube.

you're still going to need a check valve or sorts on the intake manifold.

 

The only problem there is that I am running a gt3071r with nowhere on the compressor housing for a line. Any alternative without adding a bung to my hot side pipe?

EDIT: That, and I am already running my BOV off of one of the bigger vac hoses that run above the fuel injectors.

Should I just nipple off some of the ports?

 

connect boost source to where the bov vacuum source is in the pic?

but it should be a source before the throttle body

 

I'll have a look at that. I think I'm starting to understand how the system works, so I'm gonna run out and pick up some extra hose in a little bit and try to run a few configurations and see if I can find something that works.