blowoff valve

[Buck-O]

THis thread is one of the best laughs ive had on this whole board.

Seriously.

Mis-Information, and people that believe whatever they see in a movie, read in a ricer magazine, or what the guy down the street with the bondo and primer colored Civic DX with the 3 foot tall wing, "body kit", and 20's told them, is abso-freaking-lutly some of the best comedy gold ever found.


We should really throw this conversation out the window, and start talking about Atmospheric wastegates, anti-lag, water injection, and reading a turbo map.





I guarentee every person that has no clue WTF they are talking about will leave in 10 seconds.

 

[gman07]

It seems like kids come in this thread, read what the intelligent people say about turbocharging, and throw together random/unrelated crap to try to make themselves look knowledgeable about cars. Very good read.

That depends on your definition of "kids." I'm 15 and yes, I knew what a wastegate did before reading this thread (I live on a farm and many of our turbodiesel powered tractors and combines use them). I also knew what a blowoff valve did prior to reading this. It should read "people with no knowledge of cars prior to their viewing of F&F." I do find it funny how people who have no clue what they are talking about are so willing to forget that it is better to look like an idiot than open your mouth and prove it tho.

Oh, and funny post, Greyout.

 

[Jay]

Who cares this is not a display about who knows what wastegates and bov are just let this thread die again.

 

[NamZycad3]

Actually no. If the air is released from the turbo, then it has to spin the turbine again, thus taking longer to give the engine more power. If the air is still in the turbo (with no blowoff valve) then the turbine doesn't stop spinning giving you more turbo responsiveness at a lower RPM and power when you need it.

acctually some of the blow off sound in some of the stock car is being silence ( but that doesnt mean that there is no BOV ( example like Evo, the BOV pressure will back to the intake pipe and that will make the sounds low and nearlly none ) and when you are off the pedel, the extra air will turn back into the turbo turbine and cause the turbine to slow down ( but the exaust side is still blowing gas on the turbine ) and that is very painfull, and BOV is here to prevent this from happen, but with improper setting the BOV will cause u lose power and sometime engine stall ( due to Air flow meter sense the air goes in but it already being released too much and makes the air fuel ration went too much gas side )
so if u want to get the best, one words to explain it all - BALANCE.

P/S : not everyone english is good, and i am one of the bad one haha so dont mind if i spell, or said it with the wrong way

 

[robmuzz]

hmm... so... is that a yes or no?

 

[Patrik]

hihihi

 

[Mercedes SLR]

I'm 14 and this is comedy. I hardly know anything about BOV's so I'm not going to copy a load of stuff. Take a leaf out of my book.

 

[s2000lover]

blow off valve + the back fire O_O *droools*

 

[Boost Lee]

I can think of one factory turbo car that did not come with a BOV: 1986 Dodge GLHS (IIRC). It didn't have a BOV because the throttle plate was actually before the turbo, so off-thottle the compressor inlet went to vacuum, hence no need for a BOV.

What you hear in rallying is actually compressor surge, and it's a high-pitched HEEE HEEE HEEE sound. It sorta sounds like loud brakes, but it's not.

I'm pretty familiar with the turbocharged Dodge cars / Omni's since I own one. A year ago when I made my post, I didn't even know GLH/GLHS Omni's existed. I disagree about them not needing a bov. If any car needs a bov, it's the early model turbo dodges.

And the "HEEE HEEE HEEE sound" is the wastegate chattering.

 

[shAkIeL]

You guys are hilarious!

ok, u can run ur car with no BOV i've been running mine for about 6 months, it is unsafe and really reduces the life of ur turbo. The problem is, when I race someone and i gear up to second gear or any gear going up 3rd 4th 5th, the car is pretty much constipated(or yes lagged) for a second or 2! So lets look at why this happens.. If u all can imagine ur turbo has spooled up and u are ready to change gear, so therefore boost pressure which is the air the turbo pushes once its spooled up, is going out of ur turbo to the intercooler via a pipe, then via another pipe is exits the intercooler and then goes into ur throttle body. Diagrams would explain a lot more easier..

So now going back to why a blow off valve is needed, as u can imagine it is a lot of pressure thats being pushed through into the throttle body.. now when we go to change gear and throttle butterfly closes(when letting go of the accelerator) where does all this pressure go? back to where it came from, so back through the intercooler back into the turbo, and then out of ur airfilter!! which is wat causes compressor surge! making the car temporarily constipated!!! being the turbo is trying to push out boost pressure, but there is already a load of pressure coming back at the same time.

So do we have an idea of how a blow off valve fits into all this? before the wasted pressure travels back to the turbo, the BOV(which is mounted on the piping anyplace between the throttle body to the turbo) is opened by the vacum line which begins vacuming once u release ur foot off the accelerator, which at the same time all ur boost pressure is running back to the turbo.. So blow off valve opens then psssshh lets it all out! no temporary lag. plumb back is when there is a pipe or hose that is attached to the blow off valve and to the air intake piping, just after the air filter and before the turbo. so the psssh air is circulated back to ur air intake piping, so there the air is being released(but still has not gone through the turbo) and the air is then sucked back into car..

all factory turbo cars come out with the factory blow off valves plumed back. u can usually start hearing the psssh when u add an aftermarket air filter or add boost. But its nothing compared the having it not plumed back, which i guess creates problems like we have in Australia about Noise Pollution. PSSSH! Just any excuse for the police down here to pick on imports..

 

[gmartin]

Uh yeah, when I started this thread a long time ago I really didn't have a clue about turbos. It's a little different now, thanks for the insight...

 

[TheCracker]

On a similar note to this thread - do any of the Group B cars in GT4 have audible 'wastegate chatter' like they did back in the day?

 

[cmetom]

short post is short

 

[Daddybird]

I'm a very oldskool member of Supercars.net forum, and this thread is like the most threads in there, who's got the greatest dick? You suck, I know better.

 

[kinigitt]

On a similar note to this thread - do any of the Group B cars in GT4 have audible 'wastegate chatter' like they did back in the day?

doubtful. the rally cars do not sound like rally cars in GT. never have.

real life group b car: pop hiss snort pop squeek

gt4 group b car: wrrrrrrrrrrrrrrt whimper wrrrrrrrrrrrrrrt.

rinse and repeat.

 

[Wright1331]

One thing I've noticed in gt3, which I hope they fix in gt4, is the sound of the blowoff valve. Most cars these days that come with a turbo from the factory don't have a blowoff valve. And actually, there isn't really a need for it. It's not like you're gaining any power, you're actually losing power because it's letting all the air out of the turbo so the turbine has to spin all over again. If you can't hear the blowoff valve in gt3, get a turbo'd car and get the inside view while reving it, you'll hear a sort of hissing sound. While I like the sound the blowoff valves makes, the sound in gt3 is kinda fake and should be fixed in gt4. Or, at least have an option to take it off. The sound in need for speed underground is probably the closest I've heard to a real blowoff valve in a racing game. It actually changed depending on how high the rpms were which was cool. Anyway, that's my two cents.

YOU are a DUMB @ZZ!!!! pardon my french

A blow off valve releases the pressure from the intake, and it helps the turbo to keep spinning. It releases the pressure from the Intake piping, and will pump it back into the intake or to the atmosphere. It releases pressure so that the turbo can keep spinning between shifts, so that the pressure doesnt build up too much and stop the turbo. You can only have so much pressure in the intake before it will stop the turbo dead ( literally) in its tracks.


edit below:
Sorry for the hate,lol i just read the rest of the replys and found out that someone else explained it and all is good now


shAkIeL here is your pic

 

[Wright1331]

Every factory turbocharged vehicle that I can think of, and that I have seen, has a compressor bypass valve. A cbv is plumbed back into the intake and is almost impossible to hear from outside or even inside the vehicle.

A blow off valve or relief valve is typically vented to the atmosphere. No matter what valve design you have, they all serve one purpose: Prevent compressor surge

Exhaust spins the turbine - The turbine is connected via a shaft to the compressor - The compressor brings in the air. When you let off the gas pedal the throttle plate closes and that extra air that didn't make it into the manifold slams into the plate causing it to go backwards and attack the compressor, forcing it to spin in the opposite direction = bad news. A bov-cbv prevent that air from ever reaching the compressor, and in turn keep it spinning in the right direction.

leave it to a fellow DSM'r, lol
im glad to see you know turbo's, or else i would really be dissappointed

 

[Red Six]

I disagree about them not needing a bov. If any car needs a bov, it's the early model turbo dodges.

i second that, your turbo is a hurtin unit without the sneezer on it!

 

[Taneras]

... Yea...

So how is the sound compared to GT3? Better or same?

 

[Red Six]

... Yea...

So how is the sound compared to GT3? Better or same?

so so anyone??????

 

[HKS_T51KAI]

sorryz for butting in, but to any one who actually has GT4 please tell to me and the rest of us that don't have it, are the Blow Off Valve sounds changed......
or sound the similar to GT3. RRMMM...PTSSSSHH..... We would be pleased if someone
told us turbo freaks.

 

[Jay]

sorryz for butting in, but to any one who actually has GT4 please tell to me and the rest of us that don't have it, are the Blow Off Valve sounds changed......
or sound the similar to GT3. RRMMM...PTSSSSHH..... We would be pleased if someone
told us turbo freaks.

From the HKS Genki D1 S15 Silvia GT4 drift vid I watched I didnt hear any bov, you can hear the sucking of the intake and hissing on boost but no blow off.

 

[s2000lover]

u can hear the blowoff valve sound in the option stream Z with 770+ bhp, in the inside view. Its different to Gt3's bov sound, not as loud, and hmm duno how to decribe it...

 

[Safe Speed]

Oh! Thanks for the information on BOVs, now I can forget about spending $100 on something completely worthless (except for the nifty "psshhhhhhhh" sound )

👎

 

[GT Freak!]

Here is my undestanding of blow off valves. I may be entirly wrong as i am only speculating. The hissing sound of the blow off valve is alwasy heard when the accelerator is depressed. I know that a turbo sucks air into the engine, so am i right in thinking that a blow off valve releases the pressure in the engine so no more air is forced into the engine while braking or costeing. other wise the engine would still have air forced in the engine from the turbos resulting in the engine continualy firing resulting in power still being created when you dont want it to. I hope i am making sense! If a am wrong do correct me and inform me of what the dump/blow off valve actualy does!

 

[Jay]

Here is my undestanding of blow off valves. I may be entirly wrong as i am only speculating. The hissing sound of the blow off valve is alwasy heard when the accelerator is depressed. I know that a turbo sucks air into the engine, so am i right in thinking that a blow off valve releases the pressure in the engine so no more air is forced into the engine while braking or costeing. other wise the engine would still have air forced in the engine from the turbos resulting in the engine continualy firing resulting in power still being created when you dont want it to. I hope i am making sense! If a am wrong do correct me and inform me of what the dump/blow off valve actualy does!

You are muddled up, I cant be bothered explaining it again, there is plenty of explainations on how they work like this one below

but what we are talking about now is can you hear the blow off in GT4, we've already discussed how they work

Every factory turbocharged vehicle that I can think of, and that I have seen, has a compressor bypass valve. A cbv is plumbed back into the intake and is almost impossible to hear from outside or even inside the vehicle.

A blow off valve or relief valve is typically vented to the atmosphere. No matter what valve design you have, they all serve one purpose: Prevent compressor surge

Exhaust spins the turbine - The turbine is connected via a shaft to the compressor - The compressor brings in the air. When you let off the gas pedal the throttle plate closes and that extra air that didn't make it into the manifold slams into the plate causing it to go backwards and attack the compressor, forcing it to spin in the opposite direction = bad news. A bov-cbv prevent that air from ever reaching the compressor, and in turn keep it spinning in the right direction.

 

[boostsohfast]

This thread is hilarious... 👍 It would be interesting to see what kind of "facts" about turbos, bovs, fuel management, etc. we could learn if there was a gtplanet-tech.net... I mean come on guys, a lot of us didn't know you could explode your engine without a bov .. This stuff must be known!! lol


Anyway back to the topic at hand, I liked how you could hear the bov from the outside of the car like in GT2 but I will admit at times it could be a little annoying. Buying different blow off valves in the tuning area with different sounds would be a cool option but obviously not the case in GT4...

All of us in NA only have 16 more days to find the answer to all of these questions by playing the game!

 

[Jay]

It would be interesting to see what kind of "facts" about turbos, bovs, fuel management, etc. we could learn if there was a gtplanet-tech.net.

Plenty of techincal car related things are explained in the Cars in general section of GTPlanet.