What do u think of a blow-off valve on your B8??

[BlkB8Audi]

I was driving to school, when a white B8 next to me drove off with a blow off valve. I am not going to lie it sounded like a beast. Would you put one on, does it help the engine with power? Its my first Audi so bear with me, I know it may be a little ricer for some.

[tekieru]

I was driving to school, when a white B8 next to me drove off with a blow off valve. I am not going to lie it sounded like a beast. Would you put one on, does it help the engine with power? Its my first Audi so bear with me, I know it may be a little ricer for some.

I was told BOV isn't good on A4s and are you sure its not a cold air intake?

[BlkB8Audi]

it was a BOV!! really why is that??

[durrmcdanks]

The BOV tends to cause the car to run too lean, if I remember correctly.

[sevenstarz]

Thought I left this subject in the B5 forum.

Peace

[james12]

whats the difference between a blow off valve and a DV valve???

[Toecutter]

I was driving to school, when a white B8 next to me drove off with a blow off valve. I am not going to lie it sounded like a beast. Would you put one on, does it help the engine with power? Its my first Audi so bear with me, I know it may be a little ricer for some.

That is way too rice.

[xileh]

That is way too rice.

X2.
And it is not good for the engine.

If you want a litle sound in the Audi i think cold air intake/open airfilter is enought.

[A4B7GA]

whats the difference between a blow off valve and a DV valve???

Blow off means to do just that...blow off or waste...DV means diverter valve...which redirects the extra air...it sends the extra boost that the engine cant use back to the intake to recycle it. So you could assume that a BOV would cause a poor response from the engine as it is programed to expect extra boost when the engine shifts.

Thinking that through if the engine is expecting more air than it gets that would cause it to run rich...I could be wrong...but their exhaust pipes being jet black would be an indication...

[akinaboy]

Not sure about B8 but as far as I know, audi turbo engines recirculate the air back to the engine. Most of ricy cars use BOV to dump out the air that is left over basically but audi engines are not designed that way.
Correct me if I'm wrong.

[D.NGUYEN]

Not sure about B8 but as far as I know, audi turbo engines recirculate the air back to the engine. Most of ricy cars use BOV to dump out the air that is left over basically but audi engines are not designed that way.
Correct me if I'm wrong.

You are right.

[Toecutter]

Most of ricy cars use BOV to make a "psshhhht" sound to attract attention but audi owners are not designed that way.
Correct me if I'm wrong.

Fixed.

[tekieru]

Lol exactly. I was @ my local tune shop and they said B8s don't use aftermarket BOVs but a CAI will make that sound, just not as loud.

[b6onboost]

Audi's run MAF sensors and the air is metered. They use closed loop systems with a Diverter Valve, which vents boost pressure back into the intake post MAF. So if you run a BOV the air is being vented out of the system, yet the ECU still assumes its there, so it still pushes fuel. The air/fuel ratio is off and you run rich.

However, you only run lean for a second between shifts when the BOV releases. Under boost (acceleration) the BOV is closed and the car runs at the correct A/F ratio.

So it's not automatically bad, but it isn't optimal. I personally think it's ricer to have a brand new B8 and have that high pitched BOV sound. If you want sound, get an intake and the DV will make a nice 'whoosh' sound.

[Toecutter]

The only sound I want coming from my A4 is The Girl From Ipanema softly cooing out of the fourteen B&O speakers.

[KarimS3]

So if you run a BOV the air is being vented out of the system, yet the ECU still assumes its there, so it still pushes fuel. The air/fuel ratio is off and you run lean.

Which makes it run rich.
Read your own sentence, air is dumped in the atmosphere, it "pushes" fuel so a/f is rich.

[b6onboost]

good catch. dunno how i missed that. i meant to say rich.

Which makes it run rich.
Read your own sentence, air is dumped in the atmosphere, it "pushes" fuel so a/f is rich.

[1_clean_Audi]

BOV is bad for Vw/Audi

why? i put a bov on my car (jetta) and it had power but in teh end it wasnt runing teh correct way and it wuld be to rich and sometimes it woudl get into limp mode just because of teh BOV.

DV works wonders for vw/audi

why?

i whent from a bov to a dv and teh power never left and never whent into limp mode thus having teh car run the correct way and not to rich.

"Dont go for the sound Go for the power"

[Raymax_2.0t]

BOV is bad for Vw/Audi

why? i put a bov on my car (jetta) and it had power but in teh end it wasnt runing teh correct way and it wuld be to rich and sometimes it woudl get into limp mode just because of teh BOV.

DV works wonders for vw/audi

why?

i whent from a bov to a dv and teh power never left and never whent into limp mode thus having teh car run the correct way and not to rich.

"Dont go for the sound Go for the power"

Is there any possible way for you to switch 'e' and 'h' back to their normal positions? Saying 'teh' just sounds retarded.

-end rant

Oh and OP please don't put a BOV on your B8, they're such classy cars.

[Toecutter]

Is there any possible way for you to switch 'e' and 'h' back to their normal positions? Saying 'teh' just sounds retarded.

-end rant

Oh and OP please don't put a BOV on your B8, they're such classy cars.

"Teh" is ricy.

[tekieru]

B8 + cold air intake + stasis exhaust = all the sound you'll ever need.

[akaisuzu]

No company offers Cold Air Intake or Airfilters yet for B8 A4 right?

[B_Boy]

No company offers Cold Air Intake or Airfilters yet for B8 A4 right?

that correct, i heard rumors that Carbonio will be coming out with one in mid-june....keep ur fingers crossed!!!

[JMUCI]

No company offers Cold Air Intake or Airfilters yet for B8 A4 right?

I contacted EVOMS a couple weeks ago and they said their intake would be released in 2-3 months.

[fusionx]

hahahahhaha oh man, last time someone posted something about this on the b7 forum it turned into 20 pages

[jimmya4]

http://www.audizine.com/forum/showth...&highlight=bov


excuse all the off topic.

basically gays are gay and spacers (what you call bov) are your own opinion. all i can say is no problems with mine after 10k. some of the more bro girls like it alot other than that i have had no comments.

ps - no one argue with me cause im not saying its good or bad i just like mine thats all

[JMG]

The desire to use a BOV for the "psst" sound on an Audi A4 has dated back to the B5 A4, and that debate has been restarted with each new generation of driver and build. Generally the use of a BOV on a close to stock Audi has been frowned upon because the A4 has been a closed system which utilizes a DV as opposed to an atmospheric BOV. Even some BT Audis don't need it.

I suggest doing some research on what a BOV does and what types of systems they are good for. Then determine where your car's (the B8) MAF takes it's measurement, if its an open or closed system, and what kind of gains you will get as well as the risk factors for using a BOV on your car.

What does an MAF do? On the B5-B7 A4 the MAF metered the intake air mass. This measurement is used to calculate the required fuel to be injected in order to maintain a proper air/fuel ratio. Because air mass reading is taken from the intake, venting air after the intake makes this reading inaccurate.

What does a BOV do? It releases excess air when the throttle plate is closed so as not to cause excessive stress to the turbo. When a BT setup running lets say 20-30 psi, experiences pressure surges, this can significantly affect the time needed to "re-spool" the turbo, cause premature wear and tear, and even cause damage to the turbo and blowout. Thus, the BOV is used on high performance big boost cars which have been tuned to adjust for the air released by a BOV. For those that know what a BOV does and where it is needed, the sound is associated with highly modified turbo cars. For others, it just sounds cool. Or maybe it sounds cool because we have heard fast cars make that sound?

Why didn't the A4 already come with one if it works so well? I'm not too sure, but the fact that the A4 uses a "closed" system is either a result of or one of the factors of using a DV instead of a BOV. Either way, the MAF and ECU were designed with a closed system in mind.

Note that there are also "spacers" which allow for the BOV sound while still being able to use a DV. The Spacer still makes the system atmospheric, venting air that was measured by the MAF. While some spacers are adjustable, they are still venting metered air.

One such spacer is made by Forge Motorsport, who expressly state that:

We have NEVER claimed there to be any power or performance gains from this product, HOWEVER, along with everyone's (valid) concerns as to the venting of metered air, it is important for us to provide evidence that we have offered a product that does not negatively effect performance in any way.

source: http://forums.vwvortex.com/zerothread?id=2651617

To summarize, the B5-B7 A4 was not designed to use a BOV or Spacer. The Spacer, which when used in conjunction with a DV, vents metered air, thus providing BOV functionality. The spacer/BOV has not been shown to improve performance in the 2.0T FSI and the manufacturer makes no claims that it will. Thus the BOV almost purely cosmetic for the B5-B7 engines with the stock KO3 running 8-9psi.

What's wrong with a purely cosmetic mod? Nothing. But I do have the opinion that a mod should not misrepresent or give false impressions of the car it is placed on. This would include such mods as false badging (ie S4 badges on a A4, Turbo badges on a NA car) and fake BOV generators such as this:

Fake Turbo Sound Whistler

The Fake Turbo Sound Whistler does not hurt or increase performance. It's purely cosmetic and a complete misrepresentation of the car it's placed on. I wouldn't say that a BOV on a stock A4 is as much of a misrepresentation or nearly as reprehensible. But, taking into consideration that the BOV is designed for big boost turbo setups running, for example, 20-30psi, it is my opinion that the BOV would be a misrepresentation of my vehicle unless I am actually generating those kinds of numbers. There are those who think it's fine to make others think that their vehicle produces the boost levels that require the use of a BOV when they, in fact, do not, but I am not one of them. On the other hand, there are those who don't even know what a BOV truly does or when it is needed, so there is no misrepresentation at all. The sound is just "cool". IMHO that does no service to the enthusiast crowd as a whole, because the entire meaning of the mod is closer to being lost to nothing more than a cosmetic sound. I don't know about you, but that doesn't sound like the ideal way to promote the community.

In the end, you make your decision. What is important to me may not be important to you. Take as many facts you can into consideration when you make your decision, and know that not everyone is going to agree with your decision or appreciate your mods, and they may have a good reason in their own mind.