# HKS SSQV BOV bad for 2.0T FSI?



## bwzimmerman (Jun 16, 2007)

So after searching I am even more confused.. I want to replace my DV, but not sure if I should go with just a mechanical Forge DV... or if I could use a HKS SSQV BOV. I love the sound.. dont say its ricey cause its not.. a fat can is ricey.
Anyway, someone mind educating me on the issues with a BOV and DV.


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## bwzimmerman (Jun 16, 2007)

hmm found a good bit of info on google.. so the DV deverts the air back into the intake.. but a BOV lets in into the atmosphere (no $h*t, lol) which can cause the engine to run rich since the vented air has been calculated into the Air/Fuel ratio seen by the ECU. So what about the Forge Spacer.. does it cause same problem as BOV?


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## Forge US (Jul 31, 2002)

*Re: (bwzimmerman)*

The distinction with our spacer is that it still retains the ECU's electronic control over valve actuation.
The use of a valve like the HKS is problematic because the ECU cannot control the valve's function preventing the residual pressure from being discharged when the ECU sees fit.
This application is not nearly as suceptible to fuel trim issues with the use of an atmospheric setup as other MAF-based turbocharged applications, so it's not the atmospheric function that causes a problem, but the need for specific control over the valve and how it operates.
We would not offer the spacer with an unlimited lifetime warranty and money back guarantee if it caused any issues. We spent ample time testing it as thoroughly as possible prior to putting it into production and making it available. We've sold multiple thousand units since we first introduced them 2 years ago and there have been no issues with them thus far.


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## bwzimmerman (Jun 16, 2007)

Nice, well I cant wait to get a Forge DV.. but it will come soon.


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## RedBull_MkV (Feb 5, 2007)

I had the HKS BOV settup. I noticed no problems whatsoever. It was pretty good IMO.


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## MKV2nV (Oct 20, 2007)

I fabricated my own HKS BOV kit and it works excellent. Theirs more to it then just putting the bov on but I have had it on my car for the last two months and no problems. I have also done some logging to check for any issues but all is good.


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## RedBull_MkV (Feb 5, 2007)

*Re: (MKV2nV)*


_Quote, originally posted by *MKV2nV* »_I fabricated my own HKS BOV kit and it works excellent. Theirs more to it then just putting the bov on but I have had it on my car for the last two months and no problems. I have also done some logging to check for any issues but all is good.


I had it in for 4 months with no problems whatsoever... Maybe the only problem was everyone breaking their necks watch my GTI roll on by.


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## wunderman4 (Apr 27, 2006)

what about the s3 throttle body pipe with the hks ssqv bov mounted on it and the noise pipe is used as a recirculate thing into the intake. I here this is a good setup to prevent " compressor surge"


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## bwzimmerman (Jun 16, 2007)

hmm, anyone with experience with this?


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## brandon0221 (Mar 7, 2007)

*Re: (bwzimmerman)*


_Quote, originally posted by *bwzimmerman* »_hmm, anyone with experience with this?

No, but I have had the HKS SSQ BOV for about a year now and no problems whatsoever so I don't know what they are talking about when they say "problematic".


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## bwzimmerman (Jun 16, 2007)

are there any DIYs on the HKS SSQV BOV?
I understand what they are saying.. the ECU is designed to think the air is being deverted back to the intake system and not vented out of the system. With that being said the ECU in theory could increase fuel expecting that air to be in the intake, when its not.. causing the engine to run rich.


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## RedBull_MkV (Feb 5, 2007)

i dont think there are any written FYI's. but it's very easy to install (as long as u have a vac line). U just fit the silicone pipe attached to the BOV to the noise pipe and you're good to go!


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## bwzimmerman (Jun 16, 2007)

maybe i need to look around more.. but where is the noise pipe? behind the engine? I heard it goes into the firewall.. but where passenger side?
Also does the EJ EA pipe replace the noise pipe? I want to streamline my air intake system.. ill ask it in another thread though.


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## RedBull_MkV (Feb 5, 2007)

your noise pipe is on the left side of the motor. it comes out of the fire wall then loops downward in the front right corner of the motor. at the area is where you would put the BOV.


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## umidku (Nov 26, 2007)

*Re: (RedBull_MkV)*

there is plastic pipe and rubber hose connected to noise box hidden somewhere close to passenger compartment. i did cut the rubber hose and install there T-piece (plastic one). I groove plastic in such manner, that I had edges (5 mm or so) with more diameter than the rest in order to let clamp to fasten the hose on T-piece securely.
BOV valves are 2 diff. design: pure blow-off or recirculation. For recirculation valve there is pipe outlet on the valve body, so you can connect rubber hose from it to you intake of turbo. Distance is quite short there. Just blowing was ok for me, but some people mentioned about engine running reach which is not good, but acceptable.


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## forcefedvegas (Aug 10, 2007)

I still havnt heard a good argument as to why a mechanical BOV is soooo inferior to a forge. Granted I bought one but have yet to insall it. The one that is installed right on the factory dv mounting point still recurculates like the stock and forge.


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## prodigymb (Mar 9, 2004)

mmm considering 2.0t recirculates after the maf you should be able to run a BOV without problems as a lot of people do here. hks ssqv is a great piece, i def recommend it from previous experience


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## Arin (Jun 27, 2002)

*Re: (prodigymb)*


_Quote, originally posted by *prodigymb* »_mmm considering 2.0t recirculates after the maf you should be able to run a BOV without problems as a lot of people do here. hks ssqv is a great piece, i def recommend it from previous experience

I was under the impression the MAF meters the air coming into the system, then upon DV activation, calculates the amount ingested by the engine, and then subtracts the amount that passes back though the MAF upon recirculation. So at that point it would know how much air is currently beyond the MAF for correctly calculating the air fuel when you get back on it. If this is true, wouldn't blowing off the air make the ecu assume there is more air in the system, throw in more fuel to meet the specified air fuel ratio, and cause a rich environment before the o2 sensor detects the car is running rich and trims fuel?


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## prodigymb (Mar 9, 2004)

if it does take that into calculation than what you said is correct, however i dont think it works like that. the maf measure the air that comes through it, that is why we were able to run forge spacers iwthout problems and most who run the hks dont have problems either. hks is on my list but for now move to bigger and better things


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## syntrix (Aug 20, 2000)

*Re: (prodigymb)*

Front wideband O2 sensor is your primary snitch to the ecu.


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## Arin (Jun 27, 2002)

*Re: (prodigymb)*

I just looked up some more information not related to our engine specifically but may apply since we have a MAP sensor, which would support what you said:

_Quote »_Engines with a manifold absolute pressure regulated ECU or where the blowoff is mounted upstream of the MAF sensor are not affected.


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## prodigymb (Mar 9, 2004)

*Re: (syntrix)*


_Quote, originally posted by *syntrix* »_Front wideband O2 sensor is your primary snitch to the ecu.
yup


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## umidku (Nov 26, 2007)

*Re: (prodigymb)*

right. MAF measures air moving in both directions and doesn't subtract air which is moving back....
in case of BOV controlled by original DV coil, which opens valve when pressure tends to raise, you will have more leakage and so, difference in a/f ratio.
if BOV holds pressure and opens only when you depress throttle, comparing to air mass in total, leakage is lower and difference is quite small, not really affecting to operation of engine.
but such a valves cause having soon problem with PCV due to spikes of pressure.


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## forcefedvegas (Aug 10, 2007)

*Re: (umidku)*

Here is that valve adaptor that I posted abput earlier.
http://www.atpturbo.com/Mercha...e=FSI
It still recurculates just doesnt allow the ecu to dump boost for traction control or other situations


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## bwzimmerman (Jun 16, 2007)

time to bring back a dead post.. i made a new one when i couldnt find this one.
So, I still have a few questions for those of you with the recirc BOV setup... does it have any blow off sound at all?
Also can anyone confirm that the ECU can calculate how much air is in the intake even if the air have been blown off into the atmosphere?
I am just guessing, but I think the BOV system isnt inferior to a DV system, I just think VW wanted the 2.0T to be mild for the average joe who just wants a car and not a modified or sporty car. So the DV system returns the air and doesnt make a "ricey" or "Too Fast, Too Furious" sound... cause the average business man or familly guy doesnt want that. Just my guess... especially since most car manufactures design a car to be quiet and comfortable even if it restricts power and performance. ie. most stock exhaust systems and intake systems are designed with resinators and baffles to restrict noise.
Anyway have problems with a BOV setup yet? I see someone has theirs up for sale...


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## brandon0221 (Mar 7, 2007)

*Re: (bwzimmerman)*

Still no problems here with my HKS!


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## x9t (Sep 19, 2005)

Dont all German cars use DVs.. i know audi does.. 
Have you looked into BSH kit? 
I have had my Forge DV with no Issues. 
JT


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## bwzimmerman (Jun 16, 2007)

I know the DV will be no problem, I am just debating if I can do the BOV without issues. I am trying to understand if the 2.0T ECU can calculate the air/fuel ratio correctly when the air is vented into the atmosphere. I am also wondering if the HKS DV (BOV with Recirc kit, which makes it a DV) makes the BOV sound.
Yes, I am doing all this to make a "cool" sound. I want to turn heads.. the BOV sound is impressive in my opinion.


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## [email protected] USA (May 17, 2007)

*Re: (prodigymb)*


_Quote, originally posted by *prodigymb* »_if it does take that into calculation than what you said is correct, however i dont think it works like that. the maf measure the air that comes through it, that is why we were able to run forge spacers iwthout problems and most who run the hks dont have problems either. hks is on my list but for now move to bigger and better things









Our MAFs are capable of reading in two directions, even the 1.8ts could do this.


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## [email protected] USA (May 17, 2007)

*Re: (Arin)*


_Quote, originally posted by *Arin* »_I just looked up some more information not related to our engine specifically but may apply since we have a MAP sensor, which would support what you said:



Actually we don't have a map sensor, people call it that even I am guilty because its just easier but is not a map sensor. The pure name of it proves we don't have is as its manifold absolute pressure sensor and ours is mounted before the manifold. It is simply a boost reference sensor used to control boost and trigger safety measures in the ecm if spec boost is exceeded or even not reached. Yes it does other things but a map in regards to what that quote is referring to would be used for fuel control, which ours is not.


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## JaxACR (Dec 6, 2007)

*Re: (bwzimmerman)*

So what was the outcome? I see in your sig that you've got the HKS installed. Is it working out ok for ya? Are you running the recirc adapter or blowing off to atmosphere? Did you mount it to the stock DV location or use a relocating kit? Any CEL or driveability issues? Have you done any logging to check A/F ratio and requested vs. actual boost?
Oh, and last but not least, how's it sound?


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## Boosted_Bunny (Apr 23, 2003)

*Re: (MKV2nV)*

I had an HKS set up and removed it. I've always really liked HKS, but here's the thread TRYING to explain what symptoms I was feeling...
http://forums.vwvortex.com/zerothread?id=2963667
I think the BOV wasn't staying open long enough to let out ALLLL the boost (even at chipped levels) so I was getting the lurky jerky's I describe.
Has anyone else noticed this AT ALL with this set up? I miss the part, I like the part, but couldnt' deal with this side affect.... Anyone do anything (change springs in the HKS valve, build a boost resevoir like we had on the 1.8T, etc) to deal with such a symptom?
I have the Forge unit now and am working through some things on it currently and am still very interested in seeing the HKS work to it's full potential (if that's possible) on our cars.


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## bwzimmerman (Jun 16, 2007)

To answer Jax. Yes, I do have it installed.. I originally bought a throttle body pipe with a noise pipe bung (Stock GLI/GTI pipe)... and then hooked up the vac line to control it. I used an ATP block off valve to block off the stock DV. That allows the computer to think it still has control and makes it look like its still hooked up for the dealer.
I now have an Eurojet FMIC and had them weld a noise pipe bung on it, I must say the HKS is alot louder and not annoyingly so. If you like turbo car with a BOV then you will love this. It fixes all the "problems" i had with the stock DV and spacer. (the long hiss of the DV staying open when low RPMs)
Anyway, I love it and dont plan on changing it. I do have the part needed to turn it into a full relocated DV setup when I get my turbo kit.


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## fastconti (Jul 25, 2007)

*Re: (bwzimmerman)*

I thought the idea behind the diverter valve was to recirc air back for quicker spool when the throttle closes. Rather than simply blow off the air already in the system, the diverter valve feeds it back to the intake, supplementing the air supply or allowing air mass for the turbocharger to continue speed. Boosted air entering the system at turbo intake would decrease lag time for the turbo's spool by maintaining momentum of the turbine.
Could this also be why intakes do not have a large effect on diverter valve setups? The demand for more air is already met through the recirculated air.


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## bwzimmerman (Jun 16, 2007)

well that is beyond my realm of knowledge. It make perfect sence that a BOV is not best for our cars. Logs from most major car tuners on here say that its 100% safe. I had my car on the dyno with a spacer/bov and it didnt preform an diffrent when the air was blow off.
I am sure the DV setup is best its how the car was designed and it recycles the air so it would make since that it helps spool faster.
I would say its best to move the DV from the stock location. [email protected] is currently running the S3 stock setup. ALL aftermarket DV and BOV use vac lines. The Forge replacement valve has a plug for the stock harness but it doesnt accually control the DV it just makes the ECU happy.
I would say the best setup for this car is the stock DV mounted in the S3 location (its where most relocation setups for the MKV are)
reasons:
- ECU maintains control of the DV (cause its a stock DV)
- The relocation off the turbo reduces the surge and spike that people notice (due to it being directly on the turbo)
- It will make it easier to check the stock DV for tears and damage.

Anyway, I still love my HKS and dont plan on changing.


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## Boosted_Bunny (Apr 23, 2003)

*Re: ([email protected])*

bw.... i PM'ed JC for info on that S3 relocation... that's QUITE interesting.


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## JaxACR (Dec 6, 2007)

*Re: (GotHerFast)*

*bwzimmerman-* Thanks for your comments. I actually bought my SSQV from JC http://****************.com/smile/emthup.gif Are you sure the electrical harness on the Forge DV doesn't do anything? From the looks of it, I would think that it uses the ECU signal to operate a solenoid that lets vacuum reach the DV. Therefore, it retains the ECU control over the DV, yet it is a vacuum-operated, mecahnical DV. Which leads me to my next theory (which I was about to post in GotHerFast's thread







)
*GotHerFast-* I read your thread, it got me thinking: There has to be some way to retain ECU control of the SSQV (see Forge DV). Do you think it would be possible to use an N75 or some other electrical valve (??) that would act as a vacuum switch to control the SSQV? That should solve your problem and keep the ECU happy... If you have any thoughts on this, good or bad, please let me know. I don't know much about the N75, but from what I understand, it seems like it is just an electrical solenoid controlling vacuum on/off. I think the N75 (as well as Forge's adapter) has three vacuum leads though... I assume one is vacuum from the engine, one actuates the wastegate (N75) / DV (Forge), but what is the third one? I just ordered my DV block-off plate, so I'm going to try the SSQV when the plate gets here next week. I've got a friend who is going to let me borrow an N75 to test out this theory, but if you have any insight please let me know.
Cheers!








*EDIT:* I almost forgot to mention, I did look into the S3 setup. It looks like all you need is the throttle pipe w/ bung (or a stock GTI/GLI pipe), the elbow hose w/ bung that goes from the stock airbox/engine cover to the turbo, the pipe to connect the two, and maybe a silicone coupler and a few clamps. I called World Impex and they can source the parts, but there is a 3-4 week lead time








Cost for the two parts (already got a throttle pipe) was ~$150. I can find the part numbers if anyone's interested...


_Modified by JaxACR at 12:30 PM 3-13-2008_


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## Boosted_Bunny (Apr 23, 2003)

*Re: (JaxACR)*

The three vacuum lines (from what I understand) go from the vacuum tap into the controller module, then from the module into the bottom of the valve and another into the top. One feed provides a constant vacuum supply that keeps the valve closed under boost conditions, the other actuates the valve based upon the instructions received from the controller module. 
I'm sure Mike can correct me.








I was thinking about this too, (electronically actuating the HKS), but since there is a third vacuum portion that makes the Forge controller work, I'm not sure how it would translate... but I'm starting to wonder if maybe I had gotten a bum valve, since no one else has any clue what problem I'm talking about...!


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## JaxACR (Dec 6, 2007)

*Re: (GotHerFast)*

Hmmm... So if one could get a hold of the vacuum switch that Forge uses with their DV, couldn't you just cap off the constant vacuum feed and hook up the 'switched' vacuum to the SSQV? Since the SSQV is a push type valve, it doesn't require vacuum to keep the valve shut, right?


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## Boosted_Bunny (Apr 23, 2003)

*Re: (JaxACR)*

I'd love to think that's the case (though I doubt it--my luck really)... if I do go back with the HKS, I will try that, I've thought of trying that just for laughs since I have the Forge unit right now.
I'm no where close to trying it at the moment just because I've gotta get a way to re-locate the wire to the front of the engine bay to plug in the Forge controller.


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## JaxACR (Dec 6, 2007)

*Re: (GotHerFast)*

I've got another idea kicking around in my head for ECU control of the BOV. When I get my parts and get the SSQV on I'll let you know how it turns out. May just be half-baked


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## teeOHkay (Feb 22, 2008)

i just installed an hks blow off valve yesterday in my 07 gti and it doesnt have that many problems. once and a while you will feel a fuel cut when you hit the gas so the engine feels like it lags for a second before it wants to get going. and also occasionallly the car will stall when your stopped for no reason. but other than that, no codes and it sounds amazing


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## bwzimmerman (Jun 16, 2007)

i have had fuel cut or stalling. It does have minor querks, but nothing that would make me think it is bad. If you get the boost up and blow off and then get it up again, then you will notice some "lag" an a "stall" feeling. I imagine that can be bad cause the ECU was expecting the air to stay there, and 24 PSI is alot of air to blow off and have the ECU expect it to be their fuel wise.


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## Carfreak226 (Feb 6, 2008)

*Re: (bwzimmerman)*

quick question, are you guys using the manual tranny, or is this problem also occurring in the DSG? 
Also, I know you guys are talking about this HKS BOV valve, but the one I have been looking at the GReddy RS BOV says that it actually improves boost response, and reduces lag. Any thoughts? I'm looking to buying this, but i'm still in debate over whether I should have the BOV or the DV. I want power, and a cool noise, but not the illusion of power with a cool noise. If I could use an aftermarket BOV, but keep it the stock feel of power and response from the turbo I'll be happy.


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## bwzimmerman (Jun 16, 2007)

*Re: (bwzimmerman)*


_Quote, originally posted by *bwzimmerman* »_i have had fuel cut or stalling. It does have minor querks, but nothing that would make me think it is bad. If you get the boost up and blow off and then get it up again, then you will notice some "lag" an a "stall" feeling. I imagine that can be bad cause the ECU was expecting the air to stay there, and 24 PSI is alot of air to blow off and have the ECU expect it to be their fuel wise.

Well it turns out my problems were from a boost leak.. i hit a large pothole and one of my crappy worm clamps broke, which caused all my issues. I assumed it was the HKS. I do the DV setup on the HKS and running it off of the vac instead of ECU control. No problems with the cars operation at all. I am going back to the OEM DV due to the fact I have the A cam and will be trying to get it replaced by VW when it fails and I dont want them to have any reason to blame my mods for bad engineering on their cam design.
Anyway, I can make it where I can swap back my HKS when I want that HKS BOV sound


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