Question Regarding Blow-off Valves

[Dead_Poetic]

So the thread automatically has to be only filled with responses answering your question? Or that the community is not allowed to give their opinion?

That's quite ridiculous. Whether or not you wanted feedback on your question, you should have expected any other kind of response, esp. when you're telling the forum the only reason this guy wants a BOV is for noise.

I came in here defending buickgnx because he was misunderstood by benzo. I also said that I agreed wanting a BOV was silly. You went on the defense instantly, spouting that your friend is all about performance and what not. Then you told me to get out just because I expressed that wanting a BOV for its noise is stupid.

If you couldn't handle the criticism about why the guy wants a BOV, then you shouldn't have even brought up that fact. I'm amazed nobody has called him a ricer yet for just wanting to make noise.

I dont understand why having a blow off valve has to be considered ricer-esque. I mean if you have a blow off valve, it means your car is turbocharged, which to my knowledge actually means that your car isnt just about looks. Especially when the car is completely stock visually. They do sound cool, and he did not know of any reprecussions of putting one on. Now he does, and is not putting one on. You know, not everyone is as lucky as you and can afford expensive bmw's and acura tl type s', which can in no way be considered rice. A blow off valve sounds cool, and lets people know that you dont only have a naturally aspirated 1.8 liter engine. I really dont understand whats so wrong about this. But, I'm done. My question was answer, albeit no thanks to reventon.

 

[Azuremen]

It is ricer-ish when you haven't done anything else to a car. You could put a BOV on something like a 1.4L turbo diesel or something, and you'd be a ricer.

Its just like putting an exhaust on a Civic that is bone stock other wise. Yeah, it sounds faster, but it isn't. Same deal with the BOV. It is just there to make it sound like you've done mad tuning to your car. And if you haven't done mad tuning, its rice. In my opinion, rice is anything you do to a car to make it seem you've done more than you really have in the way performance.

You can also hear the turbo spool on a 2.0L GLI or GTI. Same with a Subaru.

And on the BMW and Acura note... he could have bought something like an E36 M3 for under 10 grand. Or a WRX for the same price, which is faster in every way, and less likely to explode. And you can have a riced BMW and Acura TL Type S, unless that was a terribly failed attempt at sarcasm because you're envy is apparent.

And an FYI. A 2004 BMW 325i and a 2004 Acura TL both are in the same price bracket as the GLI.

Funny.

 

[McLaren]

I dont understand why having a blow off valve has to be considered ricer-esque. I mean if you have a blow off valve, it means your car is turbocharged, which to my knowledge actually means that your car isnt just about looks. Especially when the car is completely stock visually.

I never said he was a ricer or that wanting a BOV was ricey. However, the if the only reason you want one is to make noise, then yeah, it does sound rice-ish. It's just like only wanting an exhaust just to make noise instead of wanting it to help the performance.

They do sound cool, and he did not know of any reprecussions of putting one on. Now he does, and is not putting one on.

That's perfectly fine, & I'm not condemning him for it. The only reason I think he's silly is the reason he wants a BOV. For noise. If he wanted a BOV for helping his performance, I wouldn't think twice about him.

You know, not everyone is as lucky as you and can afford expensive bmw's and acura tl type s', which can in no way be considered rice.

I'm sorry, but what do my cars have anything to do with this discussion? Or are you after a cheap shot?

A blow off valve sounds cool, and lets people know that you dont only have a naturally aspirated 1.8 liter engine. I really dont understand whats so wrong about this. But, I'm done. My question was answer, albeit no thanks to reventon.

But I doubt that's reason BOVs are made. Think about it. How is wanting a BOV only for its sound any different from wanting an exhaust to make your car sound like something out of FnF?

But, you're welcome....

 

[Dead_Poetic]

It is ricer-ish when you haven't done anything else to a car. You could put a BOV on something like a 1.4L turbo diesel or something, and you'd be a ricer.

Its just like putting an exhaust on a Civic that is bone stock other wise. Yeah, it sounds faster, but it isn't. Same deal with the BOV. It is just there to make it sound like you've done mad tuning to your car. And if you haven't done mad tuning, its rice. In my opinion, rice is anything you do to a car to make it seem you've done more than you really have in the way performance.

You can also hear the turbo spool on a 2.0L GLI or GTI. Same with a Subaru.

And on the BMW and Acura note... he could have bought something like an E36 M3 for under 10 grand. Or a WRX for the same price, which is faster in every way, and less likely to explode. And you can have a riced BMW and Acura TL Type S, unless that was a terribly failed attempt at sarcasm because you're envy is apparent.

And an FYI. A 2004 BMW 325i and a 2004 Acura TL both are in the same price bracket as the GLI.

Funny.

Except Reventon drives a newer than 2004 BMW 5 series. Find me one that sells for $13,000(this is what my friend paid for his GLI) and I'll agree with you. And his Acura is also newer than an 04, and is a type s. Also much much more expensive than 13 grand.

And umm, of course I'm jealous. I'll be the first one to admit that. But that isn't why I mentioned his cars.

And he doesn't want the blow off valve because it will make him sound faster. He just likes the sound of them. Its not loud, its not obnoxious. Its subtle and it sounds different. Sets his car apart in a way. He does not want it so people will think his car is fast. He knows his car isnt an sti, he knows his boundaries, and adheres to them.

I never said he was a ricer or that wanting a BOV was ricey. However, the if the only reason you want one is to make noise, then yeah, it does sound rice-ish. It's just like only wanting an exhaust just to make noise instead of wanting it to help the performance.

That's perfectly fine, & I'm not condemning him for it. The only reason I think he's silly is the reason he wants a BOV. For noise. If he wanted a BOV for helping his performance, I wouldn't think twice about him.

I'm sorry, but what do my cars have anything to do with this discussion? Or are you after a cheap shot?

But I doubt that's reason BOVs are made. Think about it. How is wanting a BOV only for its sound any different from wanting an exhaust to make your car sound like something out of FnF?

But, you're welcome....

All I meant by the statement I made regarding your cars is that, it's ridiculous that when someone buys a car such as a GLI people accuse him of being ricey when he decides to modify it. Its like his hands are tied because if he does this or he does that, people will automatically assume rice. Its not always as easy as getting a car like yours and not have to worry about that sort of thing.

And you are arguing on his simple ignorance. He did not know that it was at all detrimental to the car. Again, this is why he asked me to make a thread asking about it. Its really not that farfetched of an idea.

And I do agree with you, its pretty much the same thing as only wanting an exhaust for the sound. Which really is fine; What we find fault in is when people put these huge fart cans on the back of their civics thinking that they are cool because it makes a ridiculously loud sound that draws unnecessary attraction. I think we can all agree that a blow off valve on an otherwise stock GLI is a lot more subtle.

 

[bergauk]

We aren't deeming the modification of the car ricey. We're just simply pointing out that while he thought it would be cool to have a BOV. Is just plain silly. The use of the BOV just for sound is dumb. The use of a BOV for a performance gain in conjunction with other things however is not. I'd much rather see that car with a nice non showoff-y exhaust and a few more engine parts first, than see it with a BOV just bolted on for the like of the sound.

 

[McLaren]

And he doesn't want the blow off valve because it will make him sound faster. He just likes the sound of them. Its not loud, its not obnoxious. Its subtle and it sounds different. Sets his car apart in a way. He does not want it so people will think his car is fast. He knows his car isnt an sti, he knows his boundaries, and adheres to them.

If that is this case, then I do apologize. I still think wanting a BOV just for the noise is silly, but if what you say is true, then I can respect that he knows what people will consider stupid, and what they will consider alright/cool/etc.

All I meant by the statement I made regarding your cars is that, it's ridiculous that when someone buys a car such as a GLI people accuse him of being ricey when he decides to modify it. Its like his hands are tied because if he does this or he does that, people will automatically assume rice. Its not always as easy as getting a car like yours and not have to worry about that sort of thing.

I don't think that at all, so I think you've misunderstood me. I'm ALL for people modifying their cars. It gives their car a personal touch. I just think some mods are silly, and that your friend was a bit off the rocker for wanting a BOV for its noise. I'm perfectly fine with him wanting to add performance parts though if that's his game.

And you are arguing on his simple ignorance. He did not know that it was at all detrimental to the car. Again, this is why he asked me to make a thread asking about it. Its really not that farfetched of an idea.

That's cool and all, I just thought it was silly he why he wanted a BOV. But, if he realizes that it isn't the smartest idea, then more respect towards the guy.

And I do agree with you, its pretty much the same thing as only wanting an exhaust for the sound. Which really is fine; What we find fault in is when people put these huge fart cans on the back of their civics thinking that they are cool because it makes a ridiculously loud sound that draws unnecessary attraction. I think we can all agree that a blow off valve on an otherwise stock GLI is a lot more subtle.

I agree whole heartedly. I think it's silly for the noise itself, but I don't think it's anywhere as bad as wanting a fart can for some Civic.

But, ending, while I will always think anyone wanting a BOV for its sound is silly, I will respect anyone who realizes that maybe that isn't the best idea. I'm not calling your friend a ricer in anyway, just to set the record straight as well. If your friend really is all about his performance, that's totally cool with me. More power to the guy. 👍

 

[Violentmouse]

Okay I know this is way late.... But I had to say it.


Most of you need to go spend some time at some kind of formal training facility before you comment on any type of internal combustion engine questions....

heres how it works and WHY it works.

replacing the DV in the VW with an open atmosphere blow off valve does several things in this order. First: it opens the intake up so that all the built up pressure can exit quickly preventing the turbo from being forced to slow on the impeller side, this kind of air resistance causes wear and sucks down horsepower due to the turbo needing to rise back up to speeds at which it can actually compress air.
Second: most VW's have mass air flow sensors as well as manifold pressure sensors which means that even though there is compressed air in the intake before the valve opens the manifold pressure sensor registers the fact that it has lost pressure and and compensates anyways, but not before the obvious fact that the throttle should not be wide open when you shift, and sadly when you let off the throttle in a injected vehicle. THE INJECTORS STOP INJECTING. which causes a LEAN condition and thats a bad thing. so having that minute richness actually cools the turbo which is a good thing.

imagine an oxygen torch. you only need a small amount of fuel to start the initial cut, after that it relies only on heat and oxygen, when your turbo is very hot (a long duration wide open run in 4th gear) the exhaust side of the motor is RED hot and when you run your car lean you turn the inside of your turbo into a blow torch and it can melt your turbine side so badly that I have personally seen people with holes in the turbo housing and holes in the down pipe from the turbo.

Last: the turbo on the VW is controlled by the wastegate, this wastegate is held closed by spring pressure and forced to open by intake pressure. this waste valve is connected to a rod which actually manually manipulates the valve itself and you can adjust that rod length to set your pressures. by making the rod longer you maintain exhaust pressure longer causing higher boost, and by making it shorter you force it to open faster causing lower pressures at the exhaust preventing the turbo from spinning as fast, hence lower pressures.

I do not recommend adjusting the rod yourself unless you have a great deal of knowledge about forced induction and the types of internal damage you can cause by it, however the blow off valve is goof for several reasons. you dont really lose horsepower during a shift because the horsepower is a factor of internal motor velocity, however torque is what it multiplied by the turbo during a shift, and if you allow the turbo to spool out during a shift, you lose torque and therefore speed during a shift, which in turns causes you to spend more fuel to make up for the loss. but by having an open blow off you keep your turbo turning faster, you dump a minute amount of raw fuel down the cylinders keeping your cylinder temps down and your turbo temps down which also in turn prolongs the life of your components.

as far as the cool wooosh sound. slap a small K&N valve cover filter on the blow off valve, you'll be loud enough but not so loud its irritating, and you will also keep debris out of the blow off valve itself increasing its life as well

if you have any questions about forced induction don't be afraid to ask me, I have put turbos on almost every car I have ever owned. and yes that included my 1988 Jeep cherokee XJ =oP

 

[Azuremen]

Umm. Hi, welcome to GTPlanet.

you dont really lose horsepower during a shift because the horsepower is a factor of internal motor velocity, however torque is what it multiplied by the turbo during a shift, and if you allow the turbo to spool out during a shift, you lose torque and therefore speed during a shift, which in turns causes you to spend more fuel to make up for the loss. but by having an open blow off you keep your turbo turning faster, you dump a minute amount of raw fuel down the cylinders keeping your cylinder temps down and your turbo temps down which also in turn prolongs the life of your components.

So, despite the fact that power is a function of work over time, it has nothing to do with the work (torque) the engine is actually producing? And running rich is a good thing because we want fouled up spark plugs?

And of course, losing speed during a shift. Because your engine isn't suppose to slow down when you shift up, because, well, it just is suppose to sit at 6000 RPM constantly, despite those gear ratio things, right?

Why did all of this have to be said, more so when most of it doesn't actually make any sense at all?