HKS BOV Not Blowing Off! comp surge! ARGH! <<<------------------------

[wearurpjs]

ok, now before I get bombarded, Ive searched and searched and I havent found a problem similar to mine, let alone close. Although I could be wrong.

allow me to clarify...I put on an HKS SSQV on my car earlier this week, started her up, and I was shocked when it sounded just like my old one(crushed 1G BOV). upon further inspection, I realized, I had never been blowing out the BOV at all, rather it sounds like its coming out of my intake..!? Im out of ideas...spent the weekend looking for a vaccuum leak, removed my manual boost controller and reconnected the stock boost solenoid and all lines...so the vaccuum line from the manifold is going straight to the bov...and still the same. the sound changed though, its not as loud/long...still comin from the same spot. and no, nothing is coming out of the BOV, I put my hand in front of it, nothing comes out. at all.

some pics...here we go...

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stock boost solenoid

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one line of the tee going to the comp. pipe...

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other tee to the wastegate...

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source from the intake manifold going directly to the BOV...

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in. mani. vac source going directly to the BOV

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these 2 lines, there not pulling vac. at least I dont think. I pulled them off with the engine running, didnt really notice a hesitation or change in idle.

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engine bay shot

and there it is...still cant find any problems with the lines i have hooked up, theyre all where they should be...any help would be much appreciated my fellow DSMtuners.

 

[Mackzero]

I am wondering how you felt the BOV blow the boost off, when while the car is in neutral, sitting, you could rev it to 8,000 rpms normally and it will NOT make any boost. You have to be driving, and put the car under a load, or have launch control. Do you have launch control on your car? IF you have the line from the manifold going to the BOV, and connected properly, then it should work just fine...

 

[larsrya8]

I can do that with my T-25. I only tried this once... just wanted to see if it would work. I floored it until it got close to redline, then let off and quickly floored it again. When I let off I got the BOV salute. I could keep doing that for a while before I got bored and stopped. The initial rev gets the turbo spinning, and the next ones build boost. I haven't tried this now that I have the RS on though... I already had my noobish fun You can probably do the same with the 14b... it isn't that much bigger than the T-25.

Is the HKS adjusted too tight? How much vacuum are you pulling at idle? Have you tried this on the street or just idling? Any of the lines clogged?

Why isn't it recirculated!?!?!

 

[FullthrottleGST]

not sure what the problem is here, but recirculated or not it should blow off a lot of air even from neutral on a 14 because ive done it before.

 

[wearurpjs]

I can do that with my T-25. I only tried this once... just wanted to see if it would work. I floored it until it got close to redline, then let off and quickly floored it again. When I let off I got the BOV salute. I could keep doing that for a while before I got bored and stopped. The initial rev gets the turbo spinning, and the next ones build boost. I haven't tried this now that I have the RS on though... I already had my noobish fun You can probably do the same with the 14b... it isn't that much bigger than the T-25.

Is the HKS adjusted too tight? How much vacuum are you pulling at idle? Have you tried this on the street or just idling? Any of the lines clogged?

Why isn't it recirculated!?!?!

what is too tight? Ive read to adjust the screw until the fluttering stops (tighten screw down, starting from out most thread) vacuum I dont know, havent had access to a vacuum pump/gauge. I dont believe any of the lines are clogged, although thats something I hadnt thought of before. Ill replace the vac lines and see what happens.
Ive tried this only at idle. now that I think about it, I think under load it makes a different sounding flutter...but its still not sposed to be coming out of the intake?right?

and yes I know...I have the recirc fitting Im just trying to get this working correctly.
and I should be able to blow off from idle, everyone else I know that has this on their car can as well.

 

[iNEEDspeed]

I have a comment about that recirculation fitting you have on the valve. Where did you get it from? I ask because once upon a time, many moons ago, I had the SSQV valve with the recirculation fitting and it looked completely different. Mine was more of the outer shell with a fitting to connect the recirculation hose. The one you have looks sunk into the valve. If it's not a factory HKS part it could be causing the diaphragm inside to bind.

Just a theory, take it at face value.

 

[Mackzero]

Well, I suppose if you rev'd it a few times quickly it would produce boost, not very much though. I have a HKS Race BOV that is fairly large, vented to atmosphere, and the only time I have ever heard it blow off in neutral is with the launch function. I have never tried reving the motor a few times as stated above. Either way, you need to go out on the street and adjust that thing until it blows off correctly. You probably do have the spring too tight...

 

[xad_theman]

I have a comment about that recirculation fitting you have on the valve. Where did you get it from? I ask because once upon a time, many moons ago, I had the SSQV valve with the recirculation fitting and it looked completely different. Mine was more of the outer shell with a fitting to connect the recirculation hose. The one you have looks sunk into the valve. If it's not a factory HKS part it could be causing the diaphragm inside to bind.

Just a theory, take it at face value.

The thing he has in there now is not the recirc fitting, he stated that he had it and wanted to get it working right first =) thats the purple one which has different fins to change the sound of the BOV when the air comes out. If you get the gold one or have the gold one, the sound will be louder, and mroe noticeable compared to the purple one.

 

[milz]

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these 2 lines, there not pulling vac. at least I dont think. I pulled them off with the engine running, didnt really notice a hesitation or change in idle.

the two lines on top and the two lines on the side of the throttle body are emission lines. what you need to do is get some vacuum caps and put them on.. if you run without vacuum caps or the emissions lines you do have a boost leak and you should have a higher idle.
so go buy some vacuum caps!!! so you can remove the emission lines

 

[ivanr4g63]

I had a similar problem when I first installed my HKS SSQV, the trick here are the vacuum lines, I had the MBC and BOV hocked up from the same vacuum lines, and incidently I was using long vacuum lines, I had Compressor surge and all kinds of fluttering coming from the BOV, also I placed my hand on the air filter and you could clearly feel and here air coming off from there... my fix was simple:

Shortened the vacuum line (from intake to BOV) as much as I could, leaving only necesary vacuum hose and nothing more. also relocated the MBC to the Fuel Pressure Regulator vacuum source, that way the BOV will have its own un-interrumpted vaccum source.

Try that and see if it helps.

Also, you DON'T need to go for a run, or put load in the motor to build boost to hear the BOV (like stated above), you can rev at idle and it should vent properly, as a matter of fact, if you're just testing the BOV it'll be dumb to go for a run and actually put load on the motor, as you would be building higher pressure and blow intake pipes and such if the BOV doesn't work fine...

 

[Mackzero]

You need to put a load on the motor to make the boost needed to SET UP THE BOV. As I stated above. You can not set it at idle. That is the point I am trying to convey. The BOV will flutter when not set correctly.

 

[97gstnick]

what you need to do is make sure that the vaccuum line thats is connected to the turbo is coming from a source after the throttle plate.

 

[highintenzity4]

you can have the mbc hose teed into bov vaccuum line... do others install on the turbo compressor housing or what?

 

[oldman]

you can have the mbc hose teed into bov vaccuum line... do others install on the turbo compressor housing or what?

Tap your pressure source for the mbc from the compressor/j-pipe, the bov line isn't a good place for tapping your mbc for both boost control and BOV's sake.

 

[highintenzity4]

where is the compressor/j pipe? at first i had it connected to where the factory boost solenoid went which is on turbo compressor but I had it cranked all the way and it barely hit 20...

 

[oldman]

where is the compressor/j pipe? at first i had it connected to where the factory boost solenoid went which is on turbo compressor but I had it cranked all the way and it barely hit 20...

The compressor nipple is where you want to tap. Are you saying you turn the mbc all the way up and it only goes up to 20psi or are you saying you turn it all the way down and it still boost to 20psi?

 

[highintenzity4]

i was researching and now I know i think i know what to do... i would crank it all the way up and only went up to 20, I think I had it on backwards(mbc)... Anyways reason I tapped into bov vacuum was because I saw it on vfaq for the hallman mbc install... It even had a red x in installing it to the compressor nipple.. So does it matter that mine is a hallman or same thing as others?

 

[oldman]

i was researching and now I know i think i know what to do... i would crank it all the way up and only went up to 20, I think I had it on backwards(mbc)... Anyways reason I tapped into bov vacuum was because I saw it on vfaq for the hallman mbc install... It even had a red x in installing it to the compressor nipple.. So does it matter that mine is a hallman or same thing as others?

My Hallman is mounted on my radiator mount, the nipple opposite but inline with the adjustment knob goes to the compressor and the other nipple with the tiny bleeder hole goes to the actuator.

I'm well aware that vfaq, some tech articles on this site and majority of mbc instructions suggests tapping off the BOV line but I respectfully disagree with them. There many reasons why the compressor/licp source is better than the bov/intake source.

1. The main argument for using the intake/BOV source is that it's controlling the manifold poressure (what goes into the engine) so it's more accurate when in reality it doesn't matter because the boost level you see on the boost gauge is always tapped into the manifold anyway, the only difference is a slight adjustment with the mbc due to pressure drop after IC.

2. The accuracy of vacuum and boost signal to the BOV is very crucial to the proper functioning of the BOV. Most mbc will vent to the atmosphere one way or another either through a bleeder type mbc like the TurboXS Standard mbc or through the wastegate relief hole on a ball and spring type when you go WOT. This will change the pressure level on the BOV line and cause the BOV to either open too late when letting off or open too early during boosting.

3. Tapping off the compressor/licp will greatly reduce the chances of boost spike due to short route pipping.

4. In the case of serious boost leaks, it will help preventing over spinning the turbo.

5. If you own a bleeder type mbc (TurboXS) or a poorly designed ball and spring type mbc where the ball does not fit tightly with the housing allowing air to flow around the ball, tapping off the BOV/intake lines will create a vacuum leak.

 

[highintenzity4]

so thats why you have about 6 squares in ## reputation.hehe... yea i think im going to try going with it tee'd to the compressor housing... Do you recommend that eventhough I have the blowthrough setup? I see you still have the stock 2g mas... Dont know if that matters any... Thanks for your help...

 

[oldman]

yea i think im going to try going with it tee'd to the compressor housing...

Just make sure the bcs is out of the picture, many make the mistake of teeing into the original line that goes from the compressor to the bcs instead of removing that line and everything else connected to the bcs (except for the electrical plug) then run a fresh line directly from the compressor to the mbc, remember the shorter the hose the better.

Do you recommend that eventhough I have the blowthrough setup? I see you still have the stock 2g mas... Dont know if that matters any... Thanks for your help...

Does not matter, you're welcome.

 

[ivanr4g63]

You need to put a load on the motor to make the boost needed to SET UP THE BOV. As I stated above. You can not set it at idle. That is the point I am trying to convey. The BOV will flutter when not set correctly.

You're point is good, but... If you read carefully the very first post you can see that he mentioned that the BOV doesn't vent AT ALL, now, you're right when you say that you need to put load on the motor to build full boost in order to set you BOV right... you're correct, BUT you'll agree with me that even at idle and by reving the engine your BOV should do pressure relief right? but if the BOV doesn't work AT ALL like he stated first will you still recomend someone to go for a run? of course not, first you check your vacuum or even the BOV itself and once it start working, THEN you go for a run and set it preperly right... Good now we have an understanding.

Also you gotta take in consideration that not all BOV's need adjusting, i.e. the stock 1st gen BOV, the NEW style HKS SSQV (wich came with no adjusting screw) among others.

 

[wearurpjs]

my HKS is the older one (there is a screw on the back)

so if read those posts correctly...for the MBC the compressor line goes to the side of the MBC and the intake manifold line goes to the bottom of the MBC? not that any of this matters, Im running off the BCS at the moment, cause I think I had the MBC hooked up the wrong way before. As soon as I get my boost gauge on, Ill reconnect it.

As for the BOV...any ideas as to why I cant get it to blow off even in neutral? Im going to replace the intake manifold vac line this weekend...any other suggestions?

 

[Mackzero]

You're point is good, but... If you read carefully the very first post you can see that he mentioned that the BOV doesn't vent AT ALL, now, you're right when you say that you need to put load on the motor to build full boost in order to set you BOV right... you're correct, BUT you'll agree with me that even at idle and by reving the engine your BOV should do pressure relief right? but if the BOV doesn't work AT ALL like he stated first will you still recomend someone to go for a run? of course not, first you check your vacuum or even the BOV itself and once it start working, THEN you go for a run and set it preperly right... Good now we have an understanding.

Also you gotta take in consideration that not all BOV's need adjusting, i.e. the stock 1st gen BOV, the NEW style HKS SSQV (wich came with no adjusting screw) among others.

I hear ya there, my point is to adjust the BOV. If the screw is very tight, then it will not blow off unless you make sufficient boost, know what I mean? How bout this....

Make sure you have a good vac source from the manifold as stated above.

Loosen up the screw on the BOV

Rev it a few times quickly and see if any pressure is released what so ever

IF you can hear it working somewhat, THEN take it for a drive and build 7-8 psi of boost then let off, you should be able to hear the BOV.

 

[oldman]

so if read those posts correctly...for the MBC the compressor line goes to the side of the MBC and the intake manifold line goes to the bottom of the MBC? not that any of this matters, Im running off the BCS at the moment, cause I think I had the MBC hooked up the wrong way before. As soon as I get my boost gauge on, Ill reconnect it.

No, that would be wrong. Which brand and type of mbc do you have? Different types of mbc requires different hook ups. In any case, it should not involve the BOV line, the BOV line should go straight from BOV to the intake manifold and no where else.

2. The accuracy of vacuum and boost signal to the BOV is very crucial to the proper functioning of the BOV. Most mbc will vent to the atmosphere one way or another either through a bleeder type mbc like the TurboXS Standard mbc or through the wastegate relief hole on a ball and spring type when you go WOT. This will change the pressure level on the BOV line and cause the BOV to either open too late when letting off or open too early during boosting.

As for the BOV...any ideas as to why I cant get it to blow off even in neutral? Im going to replace the intake manifold vac line this weekend...any other suggestions?

If you don't even have a aftermarket boost gauge, how are you able to tell if you're building enough boost to blow off in the first place? Most of us including my BB turbo are not able to build any boost during free revving without using my stutterbox function on the eprom, not to mention it's really bad for your motor trying to build boost by free revving to redline in neutral. I think you're blowing off during normal driving/boosting conditions or else your turbo would have been dead in no time. My suggestion is to hookup you mbc and boost gauge correctly, recirculate your BOV and stop worrying about the ability to do a BOV salute in neutral.

 

[Mackzero]

Exactly.