Blow off Valve yes or no

[Int3grity]

What would be the real benefits of having a blow off valve
would I notice a spike in performance? or is it in our cars just for noise attention.

Should I get one or not?

[Kansei]

You wouldn't notice anything aside from the sound. Unless you have turned up the boost enough that your stock bypass valve is leaking boost, it won't help anything, aside from making a lot of noise.

Plus there's the huge downside of venting to atmosphere (with a BOV) on a car that uses a MAF system, basically the MAF measures air as it comes in and you'd be letting air that has already been metered escape to the atmosphere, causing the direct injection system to inject much more fuel than it needs to, making the car run rich for a little bit during and just after the BOV releases.

[spike blue]

so you saying that is not a good idea to put a bov in the ms3. ms6 and cx-7 engines???

[Int3grity]

I was looking at a youtube video of someone from these forums that installed bov and prototype down pipe the released air that you are talking about looks like it will never re enter the engine the bov is mounted on the side next to the enormous plastic engine cover

http://youtube.com/watch?v=rrYJrzb-FRQ

[knowledge007]

As stated you will not see any spike in performance. I have changed my BPV to a BOV due to the fact that the ByPass Vavle might rupture during boost. Kansei is talking about a BOV that vents to atmoshpere. You can also get a BOV that will do the same thing that your BPV is doing which is Recirculate the air back into the engine as I have mine. But that will only change the sound. You will here the BOV operating when you release boost. I personally like this mod but if you don't want to hear it recirc or you don't want be noticed on the street, or if your not boosting the car enough to rupture the BPV then just leave the car stock.

In the youtube video above, that is the BOV I have installed, but as I said I am recirculating. On the vid this demonstrates the sounds of the Vent to Atmosphere.

[SuperStretch18]

Read this:

http://en.wikipedia.org/wiki/Blowoff_valve

[knowledge007]

Their is nothing their that I didn't mention Super except the legality aspect of it. If you want the sound Int3grity to change then get a BOV that recirculates. Cannot vent to atmoshpere until you get a chip to program the ecu.

[SuperStretch18]

Their is nothing their that I didn't mention Super except the legality aspect of it. If you want the sound Int3grity to change then get a BOV that recirculates. Cannot vent to atmoshpere until you get a chip to program the ecu.

Sorry, that response wasn't directed at you, just some general knowledge for the group. I agree with you 100%!!

[spike blue]

got it i will get one but it will recirculate

[knowledge007]

Sorry, that response wasn't directed at you, just some general knowledge for the group. I agree with you 100%!!


Sweet, I know I love it...lol Can't wait to get the chip so I can get the nice whistle by venting to atmosphere.

[knowledge007]

got it i will get one but it will recirculate

If you ever want to vent to atmosphere purchase a bov that can be setup on either recirc or v to a (of course v to a is only when you reprogram your ecu with a chip) just in case you want to purchase a chip. The HKS SSQ which I have and is shown on the vid is capable of doing so. But there are others.

[Quickie]

So the cx-7 is using a diverter valve instead of a bov? I was wondering if i could use the race vavle from hks, it also recirculates when not driving so it would do the same a ssq, but its a diffrent sound. I have a vw gti running ssq, but if i didn't buy it i wanted to buy the race vavle from hks instead.

[knowledge007]

Really don't know what a race valve is. I thought that a BOV was a BOV that can either recirc or v to a depending on which one you get.

[Quickie]

Really don't know what a race valve is. I thought that a BOV was a BOV that can either recirc or v to a depending on which one you get.

http://www.hksusa.com/products/?id=759 this is the vavle i'm talking about

Also here is a link to the new ssq, they produce looks alittle diffrent

http://www.hksusa.com/products/?id=3261

[knowledge007]

Their is no difference in the two except for the psi limits. Yes the SSQ is a looks a little different but does the same thing as the other. If you look at both of them they both can be used on either RECIRC and or V to A.

[Int3grity]

http://www.hksusa.com/products/?id=759 this is the vavle i'm talking about

Also here is a link to the new ssq, they produce looks alittle diffrent

http://www.hksusa.com/products/?id=3261


that was the one I was looking at but now that someone posted the wiki definition I understand what was said about blowing off to the atmosphere. I supposed I read to quick.

some serious performance parts are in due for this car it almost makes it pointless to be a turbo @244 they shouldve slapped a v6 instead of 4cyl turbo. car still needs more power is not that fast other cars smoke my ass
but hey i bought the car because I love the style how it drives but no sports cars crossover here.

[knowledge007]

lol...its all the excess weight int3grity unless when you mention cars you are talking about suv's. But cars you don't stand chance if they have turbos unless you put some serious money into that beautiful suv.

[Quickie]

lol...its all the excess weight int3grity unless when you mention cars you are talking about suv's. But cars you don't stand chance if they have turbos unless you put some serious money into that beautiful suv.

Thanks for answering my question! i just want to put the race valve instead, because it sounds mean, also lets say they decided to dedicate to make a chip or even turbo that would surpass the limit of the old on ssq which is around 30. I
would be able to handle it anways. I say if your going for it, go for gold haha!!(drunk)

[knowledge007]

Thanks for answering my question! i just want to put the race valve instead, because it sounds mean, also lets say they decided to dedicate to make a chip or even turbo that would surpass the limit of the old on ssq which is around 30. I
would be able to handle it anways. I say if your going for it, go for gold haha!!(drunk)

Well in that aspect, the stock turbo I don't thinkn will even reach over 20 psi. With that being said I am pretty sure our mani's will not be able take anything more. Running over 40 psi is quite an experience and requires major modifications to the engine.

[lisevolution]

Coming from someone with an MSP that is running a Greddy Type-RS V2A and had to relocate my MAF to get the car not to stall, yeah the sound is cool but not worth it. You actually lose performance by not recirculating your air back into the intake tract. By recirculating the air, it helps the turbo spool quicker and more efficiently. Just upgrade your BPV to something like the boostsciences diverter valve or just by a BOV and recirculate it. If you are 100% trying to V2A you can look into the 50/50 valves from Turbosmart. They allow half the air to recirc and half to v2a...

[Quickie]

Coming from someone with an MSP that is running a Greddy Type-RS V2A and had to relocate my MAF to get the car not to stall, yeah the sound is cool but not worth it. You actually lose performance by not recirculating your air back into the intake tract. By recirculating the air, it helps the turbo spool quicker and more efficiently. Just upgrade your BPV to something like the boostsciences diverter valve or just by a BOV and recirculate it. If you are 100% trying to V2A you can look into the 50/50 valves from Turbosmart. They allow half the air to recirc and half to v2a...

So these cx-7 actually run Dv's because i have the same problem with my vdub, but i'm running v2a with ssqv. Still i'm going to buy the race valve from hks. I tried to use gfb half recirculate and half vent, it threw codes like crazy so i had to sell it. maybe i'll try a forge dv. It might work pretty well.

[mikey1981]

car still needs more power is not that fast other cars smoke my ass but hey i bought the car because I love the style how it drives but no sports cars crossover here.

i agree it may need more power in the high rev range, but completely 100% disagree about the no sports car crossover. This is the best driving suv/cross on the road. yea, it is. it drives better than most vehicles ive ever driven. The only thing i actually like driving better is my buddies BMW 5 series and his SLK AMG. Every other car i get into sucks, wether its pathetic breaks like my Hondas or the Mazda6 V6 loaner i had, or too much body lean in the 4runner w/V8 or my CRV. the list can go on n on. im talking overall driving experience here - breaks, acceleration, handling, grip, smoothness. this thing does just about everything better than whats on the road in its class/type. If it cant accelerate faster than the X3 or the RDX, it accells in other areas such as ride quality and midrange power and breaking etc etc.

now if they could only fix the check engine light.

just my 2 cents. and i cant believe im still defending this car after everything ive gone thru with it.

[Ms3Xeoc]

Plus there's the huge downside of venting to atmosphere (with a BOV) on a car that uses a MAF system, basically the MAF measures air as it comes in and you'd be letting air that has already been metered escape to the atmosphere, causing the direct injection system to inject much more fuel than it needs to, making the car run rich for a little bit during and just after the BOV releases.

Good Info there and it makes sence! Thank you for that. I am currently running a HKS SSQ BoV in V to A on an otherwise stock MS3. I have not noticed any lack of preformance or stalling/backfiring yet.... I have noticed me being a prick with it and sounding it off in ricer/domestic tuner ears though (upyours)

I keep reading about how V to A isnt great for our cars and thats the first explination I have seen about why it isnt good. Any more info would be great.

I think when I purchase my CAI I will also get them to add in the recirculation fittings for it and switch over... I'd rather not hurt my brand new baby!

I almost forgot to ask!! Anyone know who sells the chip to reprogram the ECU? and will it void a warranty?

[Quickie]

Good Info there and it makes sence! Thank you for that. I am currently running a HKS SSQ BoV in V to A on an otherwise stock MS3. I have not noticed any lack of preformance or stalling/backfiring yet.... I have noticed me being a prick with it and sounding it off in ricer/domestic tuner ears though (upyours)

I keep reading about how V to A isnt great for our cars and thats the first explination I have seen about why it isnt good. Any more info would be great.

I think when I purchase my CAI I will also get them to add in the recirculation fittings for it and switch over... I'd rather not hurt my brand new baby!

I almost forgot to ask!! Anyone know who sells the chip to reprogram the ECU? and will it void a warranty?

The reason why v to A is bad for recircuilating car's is that, some car's need the recircuilating air to hold your boost longer.

V to A would make the air leave the chamber so you lose some air that has to be made back up by your turbo.

Reason why high boost car's need to vent to A is because it has to release the air in the chamber so it does not cause vibrations or back pressure to hurt the fin's of the turbo.

but yea i'm still trying to decide what to run on the car myself so don't mind me haha!!

[9Hooker]

The reason why v to A is bad for recircuilating car's is that, some car's need the recircuilating air to hold your boost longer.

V to A would make the air leave the chamber so you lose some air that has to be made back up by your turbo.

Reason why high boost car's need to vent to A is because it has to release the air in the chamber so it does not cause vibrations or back pressure to hurt the fin's of the turbo.

but yea i'm still trying to decide what to run on the car myself so don't mind me haha!!


that's totally incorrect. read the previous replies and see why MAF cars recirculate and MAP cars vent to atmo.

[jdm_gadget]

So would the Apexi SAFC or AEM wide band air/fuel controller help to run a VTA BOV on a MAF engine? instead of chipping the ecu? Cause I really love the sound of VTA BOV and I think recirculating it won't sound as loud.

[9Hooker]

:sigh:

No. Unfortunately it's the wrong methodology. An SAFC doesn't work with the DISI/Mazda ECU. But more importantly with a VTA system EVERY time you trip the blow off valve you are running your motor very rich. In the simpleist terms, that's a bad thing. NO amount of computer chipping or fuel management standalones/piggybacks will prevent that.
And no it won't sound as loud when it's recirc.


Suggestion, just get one of these and leave the rest of the car alone

http://www.takakaira.co.jp/accessories/nightpager/nightpager.html
http://www.takakaira.co.jp/accessories/nightpager/na_blowoff.jpg

[CJS525]

:sigh:

No. Unfortunately it's the wrong methodology. An SAFC doesn't work with the DISI/Mazda ECU. But more importantly with a VTA system EVERY time you trip the blow off valve you are running your motor very rich. In the simpleist terms, that's a bad thing. NO amount of computer chipping or fuel management standalones/piggybacks will prevent that.
And no it won't sound as loud when it's recirc.


Suggestion, just get one of these and leave the rest of the car alone

http://www.takakaira.co.jp/accessories/nightpager/nightpager.html
http://www.takakaira.co.jp/accessories/nightpager/na_blowoff.jpg

Haha, one of the lamer add-ons I've ever seen...
Looks like something I'd hear on a 2002 audi a4 in a high school parking lot..

Wait till your CX-7 goes out of warranty and go with the HKS BOV.

[9Hooker]

Wait till your CX-7 goes out of warranty and go with the HKS BOV.


just promise me you'll recirculate it!

[Int3grity]

:sigh:

No. Unfortunately it's the wrong methodology. An SAFC doesn't work with the DISI/Mazda ECU. But more importantly with a VTA system EVERY time you trip the blow off valve you are running your motor very rich. In the simpleist terms, that's a bad thing. NO amount of computer chipping or fuel management standalones/piggybacks will prevent that.
And no it won't sound as loud when it's recirc.


Suggestion, just get one of these and leave the rest of the car alone

http://www.takakaira.co.jp/accessories/nightpager/nightpager.html
http://www.takakaira.co.jp/accessories/nightpager/na_blowoff.jpg


That is some funny Sh*t now we have sound effects what is next a muffler that sounds like you are riding a mean ass ride oh wait that's already out I see them everyday on mom & pop cars Toyota camry with huge aftermarkt spoiler,Spinning hub cabs that spin counter clockwise, Fake wannabe muffler Vrroooommm better watch out they might race us out LOL(five-0) (five-0)

[jdm_gadget]

Thanks for the info 9hooker. I guess i'm just gonna leave it stock for now. About that NA BOV, I dont think I can ever forgive my self if I was gonna install that.

[Ms3Xeoc]

:sigh:

No. Unfortunately it's the wrong methodology. An SAFC doesn't work with the DISI/Mazda ECU. But more importantly with a VTA system EVERY time you trip the blow off valve you are running your motor very rich. In the simpleist terms, that's a bad thing. NO amount of computer chipping or fuel management standalones/piggybacks will prevent that.
And no it won't sound as loud when it's recirc.


Suggestion, just get one of these and leave the rest of the car alone

http://www.takakaira.co.jp/accessories/nightpager/nightpager.html
http://www.takakaira.co.jp/accessories/nightpager/na_blowoff.jpg

(rlaugh) (rlaugh) (rlaugh)

I dont think that was seriously a suggestion!

I'll take the loss in noise recirculating before I gay up my ride ><

[Killer]

(rofl2) (rofl2) (rofl2)

[cricket1977]

http://www.takakaira.co.jp/accessories/nightpager/nightpager.html[/url]
http://www.takakaira.co.jp/accessories/nightpager/na_blowoff.jpg

oh that is freaking awesome, I am so putting that on my -7 (moon)

good info. that kit they have out for the disi engine has the option for recirc or v to a. i believe it's just a minor charge for the recirc kit for the hks.

[AWmustang]

Did you listen to the clips??? They don't sound anything like a blowoff valve. Not that I really expected them to. But they could have at least recorded an actual BOV.

[cdesigns]

You will notice a change on how the tranny shift as soon you disconect the recirculating hose, I didn't like it. the tranny shifts hard sometimes

[JGTO05]

Sorry, I really hate to do this...But this is an SUV/Crossover...Not a sports car. What need do you have to put a BOV on an SUV? That is just as bad as putting the BOV box on it. You are essentially doing EXACTLY the same thing as that electronic box. You are paying money and installing something on your car purley for the sound of it. There are NO positive gains from a BOV valve on this car, unless you are leaking boost. Even then, you need a DV instead of the BOV due to the MAF. I cannot understand sacrificing something for a noise. Not only that, but even if you did get the vent to astmos. to work, why would you do it? I apprecieate that this can be a fun SUV to drive, but it will never be a quick car, let alone fast. It handles great...for an SUV, brakes great...for an SUV, and goes reasonably fast...for an SUV. If you want a BOV that bad, go buy a cheap 240 with a swap, or an SRT-4. Not to be an a$$hole, but this does absolutly not make sense to me, debating if someone should get a BOV for an SUV. That is like debating which lowering springs to get for your minivan, or which exhaust to get for your hybrid.

[07LiquidCX7]

Sorry, I really hate to do this...But this is an SUV/Crossover...Not a sports car. What need do you have to put a BOV on an SUV? That is just as bad as putting the BOV box on it. You are essentially doing EXACTLY the same thing as that electronic box. You are paying money and installing something on your car purley for the sound of it. There are NO positive gains from a BOV valve on this car, unless you are leaking boost. Even then, you need a DV instead of the BOV due to the MAF. I cannot understand sacrificing something for a noise. Not only that, but even if you did get the vent to astmos. to work, why would you do it? I apprecieate that this can be a fun SUV to drive, but it will never be a quick car, let alone fast. It handles great...for an SUV, brakes great...for an SUV, and goes reasonably fast...for an SUV. If you want a BOV that bad, go buy a cheap 240 with a swap, or an SRT-4. Not to be an a$$hole, but this does absolutly not make sense to me, debating if someone should get a BOV for an SUV. That is like debating which lowering springs to get for your minivan, or which exhaust to get for your hybrid.

I agree with your position, but not necessarily your argument. I agree having a BOV "sound" should not be the primary concern in modding this particular vehicle. But from what I have read here and elsewhere... options like the Forge MS BPV do prevent boost leakage by replacing the factory one. So, there is a performance, if not just fixing a problem aspect to the mod.

But I wonder what kind of power this would make with the bigger turbo on it (from the spd3 or spd6? I forget). IMO this thing with 280 hp at the motor would be perfect. What is that on a FWD vehicle... like 240 FWHP? That would be a fun little SUV.

[Killer]

(hand)

[blkcherimika]

Killer... you kill me!

[JGTO05]

I agree with your position, but not necessarily your argument. I agree having a BOV "sound" should not be the primary concern in modding this particular vehicle. But from what I have read here and elsewhere... options like the Forge MS BPV do prevent boost leakage by replacing the factory one. So, there is a performance, if not just fixing a problem aspect to the mod.

But I wonder what kind of power this would make with the bigger turbo on it (from the spd3 or spd6? I forget). IMO this thing with 280 hp at the motor would be perfect. What is that on a FWD vehicle... like 240 FWHP? That would be a fun little SUV.

I agree that if it is leaking, by all means plug it up. If the Forge works better than the leaky stocker, then I would consider it. I had horrible experiences on my last turbo car with Forge products, but then again, I have a lot of VW/Audi friends that use them on their car. Some of them turn them backwards, which again rises my question of why? Your car runs like crap, and all you got was a "better" sound.

[rocketr2]

All CX-7 are automatic transmission, so you wouldnt get the bov "whooosh" sound when it shifts, only when reving.

[Alpha Wolf]

Well yes it is a Cross over SUV.

Yes it is not a race car.

But if something is leaking boost then correcting that is something that should be done.

More power = more fun driving (drive2) and possibly better mileage

But, due to low bang for buck, I see this as something to do only after doing those things that will boost performance more for the money.

Larger TMIC
CAI
Better Exhaust

Then BOV..

[satz]

i've read that the Cx7's stock BOV leaks.

Was wondering how we know that for sure, and also whether or not the leak is designed to protect the engine/transmission from too much instantaneous power?

What are people's long term experiences with the various aftermarket BOVs on the CX7?

Any failures? Any real benefits?

cheers

Satz

[RiP 8/23/07]

Ihave a HKS SQV and I have it vta but it isn't as annoying as a manual and if I drive like a sissy I can make it so it only blows off the preliminary valve and you cant hear it... so there is minimal loss of air in the intake... no CEL after driveing it for 1000 miles already... I have the stuff for the recirc fitting but its small and I need to make an adapter for it... gas milage sucked for 2 tanks now its gotten better once the computer adjusted to it... its all worth it to pass a ricer and let off the gas and see the look on their face... I got it used for 200 with the adapter dont think I would have paid much more for it... forge may be the way to go for the money but I'm happy with mine

[SuperStretch18]

Had the forge valve since september. No issues, MUCH stronger throttle response. I absolutely recommend the upgrade! The link below shows that even the stock MS3 valves are leaking:

Bypass Valve Tested (http://www.mazdas247.com/forum/showthread.php?t=123692617&highlight=bipass)

Regarding whether the stock valve is meant to leak; the ecu on this car has control over EVERYTHING. There are other ways that it could control throttle, boost, fuel, etc, that are repeatable and measurable. A boost leak is not really the best way to control power in this system...

[satz]

Is the difference in throttle response only felt at high boost conditions?

I guess if the stock valve leaks at high boost then that would be the case, right?

Or does it really help at lower boost as well?

cheers

Satz

[patty AT forge]

The bulk of the problem is that the stock valve leaks at boost onset. But it also leaks at higher boost levels..

[satz]

hi all

was wondering if there is any modification that can be done to the stock BOV to reduce/prevent the leak?

Perhaps stronger spring or something like that?


cheers

S

[SuperStretch18]

You could do this:

"FREE BOV's FOR EVERYONE" (http://www.mazdas247.com/forum/showthread.php?t=123694682)

I would never do it or recommend it to anyone, but since you asked...