Blow off / bypass sound like this

[jkensy]

I have a supercharger on my bmw and use a VF Engineering bypass valve, was wondering if someone can use this as a sample.

http://e34.digital7.com/1.avi

http://e34.digital7.com/2.avi

[thisnameistaken]

Maybe it's just me, but after all these threads I have to ask, what is the fascination with these "pssshhht" noises?

[jkensy]

Maybe it's just me, but after all these threads I have to ask, what is the fascination with these "pssshhht" noises?

I thought LFS was a simulator?


Don't simulators model reality?

[Gunn]

LFS does model reality. Not all psssssht! noises are the same. :)

[steve]

yes but the way LFS plays the sound is unrealistic.. it doesnt play from begining to end, and itll play from wherever it left off when it stopped.

[tristancliffe]

They sound silly however you play them. Might as well replace the pssshhhhhttt with riiiiicccceeeeerrrrrrrrfooooooooolllllll everytime they lift the throttle one iota.

:razz:

[wheel4hummer]

http://video.google.com/videoplay?docid=1868742531786469733&q=blow+off

[lrdbsi]

???????????????????????????????????????????? link to a pointless pic?

[Scirocco]

???????????????????????????????????????????? link to a pointless pic?
That link (http://video.google.com/videoplay?docid=1868742531786469733&q=blow+off) shows a video with sound and not just a pointless pic....

[wheel4hummer]

I was proving that ALL turbo car's have diiferent sounding BOV's. The XRT does not have a HKS BOV, it doesnt have a nissan skyline bov, it has an XRT Bov.

[wheel4hummer]

yes but the way LFS plays the sound is unrealistic.. it doesnt play from begining to end, and itll play from wherever it left off when it stopped.

I'd say it is pretty realistic. I mean, if you let off the gas, the throttle closes and the pressure rises, making the BOV push a spring, and open. BUT, when you mash the throttle again, the throttle opens. The pressure then can go through the throttle plate, and the BOV closes. SO, a real BOV will stop letting out air when you press on the throttle again.

EDIT: I found out the difference between a BOV and a wastegate. The wastegate opens when there is too much exaust pressure, which lets it limit the boost pressure (The exaust goes to the atmosphere instead of the turbo). A BOV is after the turbo, but before the engine. If the throttle is closed, the turbo is still spinning, and is stressed (this depends on the boost level) which could screw up the turbocharger. Instead of the turbo getting screwed up, the BOV opens, venting the compressed air into the atmosphere. A BOV is unnessasary. The wastegate is pretty much needed.

[turbopuusti]

a blow off valves 'psssshh' sound, its the sexiest noice that car can do!
but u probably ment turbocharged, not supercharged? or if u did mean supercharger, do they have blow-offs in those too?:scratchch

[tristancliffe]

A blow-off valve is the silliest noise that a car can do. Why waste all that compressed air by making a pointless and power reducing noise? Why not get a silent recirculating dump valve, make less noise (and therefore look less like a complete idiot who likes 'phat carz') and actually go faster too.

This does not apply so much on a race circuit where you want to keep the turbo spinning as fast as possible, are using high engine revs and WOT most of the time, so boost build up is very rapid. Much like WRC cars. Which is why they make that silly noise, and makes the cars sound like malfunctioning toys.

[Hankstar]

I was going to ask if a BOV actually did anything performance-wise, besides sounding like Herbie sneezing, but good ol' TC answered my question already :) I don't understand why you'd put something on your expensive hot car that actually robbed it of performance. Call me an old fogey if you like, but the only things going in or on any car of mine are to make them more fun to drive and I'll leave the cosmetics to the fashion victims ;)

[hrtburnout]

........ could I please look at it because I'd like to know what a stock Honda Civic looks like.:clapclap:

[Gunn]

You need street cred to race for pink slips, then you can demand the respect.

Doof Doof Doof Pssssssshhht! Doof Doof Doof Pssssssshhht! :hyper:
Doof Doof Doof Pssssssshhht! Doof Doof Doof Pssssssshhht! :hyper:

The default sound does not annoy me at all, I kinda like that. Some cars sound like a can of Pepsi opening and others like the disembowellment of a musabi-filled Sumo Wrestler suffering from acute explosive diarrhea.
These things are always going to appeal to racers on a personal level. It's ok to like one way or the other, whatever floats your boat. Perssssshonally I prefer a lesssssh perssssshishhtent appraoachhhh. But maybe thatshhhhh jussshhhhht me?

[mrbogeyman]

like the disembowellment of a musubi-filled Sumo Wrestler suffering from acute explosive diarrhea

nice of you to paint that picture.........:x

as for the psssssssssst noise, im sure all noises in LFS will imrpove when the sounds engine becomes the next focus of the devs attention. meanwhile i think you just have to settle for 3rd party replacement sounds clips.

[Ball Bearing Turbo]

Man, come on Tristan - usually you're one of the most sensible guys around here hehe. Beauty is in the ear of the beholder my friend, there's nothing concrete about something so subjective. As you can tell I'm for BOVs, I like them.... although I like milder ones, not personally a fan of obnoxious squeeling sounds, I don't feel that someone 3 blocks away MUST know I am releasing some boost. But to each their own. How come you called it a "power reducing noise"? If the turbo stays spooled that's a good thing in my books, I'm assuming recirculating mechanisms accomplish the same task?

edit: grammar
edit2: spelling (seemingly not awake yet)

[Huru-aito]

Recirculating BOVs/bypass valves don't dump the air to atmosphere but back to the system, if there's a marginal difference in engine power output and response between them and atmospheric BOVs/blow off valves it's right there. For a short period of time after opening the throttle the recirculating version has more air flowing into the engine = more power. Other reasons for using recirculating type of BOV is that they are less noisy and don't mess up airflow metering (mixture).

Besides, a bypass valve can be audible as well if you want, just remove any unnecessary intake scoops and resonators etc. But the sound doesn't bring any performance gain :scratchch

[tristancliffe]

Man, come on Tristan - usually you're one of the most sensible guys around here hehe. Beauty is in the ear of the beholder my friend, there's nothing concrete about something so subjective. As you can tell I'm for BOVs, I like them.... although I like milder ones, not personally a fan of obnoxious squeeling sounds, I don't feel that someone 3 blocks away MUST know I am releasing some boost. But to each their own. How come you called it a "power reducing noise"? If the turbo stays spooled that's a good thing in my books, I'm assuming recirculating mechanisms accomplish the same task?

edit: grammar
edit2: spelling (seemingly not awake yet)

Thanks - people rarely call me sensible...

The "power reducing noise" I refer to is the pssssssssssshhtt. It's the sound of power being thrown away for no reason, as explained above (thanks Huru-aito). As a purist (yes, I am) I can't understand why anyone would ever in their wildest dreams want to make their car make a silly noise at the expense of dynamic ability (i.e. all noise and less go).

For messing about at car shows and events, I'm all for noisy things. Their whole point is to entertain a crowd or provide good entertainment. But for road or track use, I don't see the point. Maybe it's short sighted of me to think like this, but this is how I think, and I like thinking like it.

[Ball Bearing Turbo]

So what you guys are saying is that the recirculating system is maintaining some mainfold pressure - which I assumed to begin with. However is the net effect of the lack of pressure drop enough to offset having to spool the turbocharger up again? I would think the impeller would still be experiencing some load keeping the manifold pressurised and would therefore cause more lag when you get back on the throttle... however I am no expert.... And I definitely agree with the philosophy stated regarding "show" (notice quotes) and no go... hehe I've always considered myself a purist as well, but maybe igorance has left me unpure on this topic LOL. I still like a little "PSsshh" so to speak however if it truthfully does actually decrease performance (I assumed it had no net effect really) then I'm facing some serious ambivalence in the near future....

[tristancliffe]

Lol

Well, the normal dump valve gets rid of all the excess manifold pressure. But there is still pressure there (up to whatever the valve is rated at) slowing the turbine. With the recirculating valve, the manifold pressure is not allowed to go above the same value, but the excess air isn't 'lost'. When you get back on the throttle, the boost can be built up much more quickly from this reserve. The normal dump valve means the turbine has to do all the work of building boost itself. If that makes sense.

Of course, if anyone can prove me wrong (not by saying 'dump valves rock innit' please) then feel free, cos I like to be corrected on things if I am wrong ;)

[JTbo]

If you are running 'insane' boost level, then you probably don't won't to let boost get back into system, turbo might get damaged as it may get overrevved. Overrevving may happen also when you have too small wastegate or too small exhaust side of turbo, this makes also heat to become a problem.

I could not care less from street respect or things like that however and there is relative quiet BOVs available too, no need to get one that has silly trumpet or whistle, some even installed duck hunting whistle(word?) to BOV and put video to net, all teenagers were going crazy, me me me I wan't one, ok I may bit bit old alredy ;)

So in my opinion we could have also car's with not so insane boost levels and without BOV too.

[JTbo]

http://www.proficientperformance.com/tech_bypass_valves_explained.php

http://auto.howstuffworks.com/turbo.htm

Maybe bit of help to all

[Ball Bearing Turbo]

Lol

Well, the normal dump valve gets rid of all the excess manifold pressure. But there is still pressure there (up to whatever the valve is rated at) slowing the turbine. With the recirculating valve, the manifold pressure is not allowed to go above the same value, but the excess air isn't 'lost'. When you get back on the throttle, the boost can be built up much more quickly from this reserve. The normal dump valve means the turbine has to do all the work of building boost itself. If that makes sense.

Of course, if anyone can prove me wrong (not by saying 'dump valves rock innit' please) then feel free, cos I like to be corrected on things if I am wrong ;)

With the recirc system ... Honestly I'm not dense (at least I don't think so :scratchch ) the volume of compressed air must go somewhere, and putting it into some other piping is not going to release as much intake manifold pressure as rapidly (the key to maintaining impeller RPM right? wrong?) as venting to the atpmosphere should. Therefore the turbocharger should have LESS work to do with an atmospheric valve installed.... And also I may be wrong and I too enjoy some construcive reproof and edification. And I am obsessed with cars / physics and turbochargers so I really should know all this already :schwitz:

note: no time to check for typos please excuse any

[JTbo]

Lol

Well, the normal dump valve gets rid of all the excess manifold pressure. But there is still pressure there (up to whatever the valve is rated at) slowing the turbine. With the recirculating valve, the manifold pressure is not allowed to go above the same value, but the excess air isn't 'lost'. When you get back on the throttle, the boost can be built up much more quickly from this reserve. The normal dump valve means the turbine has to do all the work of building boost itself. If that makes sense.

Of course, if anyone can prove me wrong (not by saying 'dump valves rock innit' please) then feel free, cos I like to be corrected on things if I am wrong ;)

Only thing that I spotted is that these valves don't lose manifold pressure, only pressure between throttle body and turbo's compressor side.

Manifold pressure keeps valve closed, when you lift throttle valve is opening. Of course it is not quite this simple as there is also this pressure thing that affects when it is opened, so it won't open wrong time.

[JTbo]

With the recirc system ... Honestly I'm not dense (at least I don't think so :scratchch ) the volume of compressed air must go somewhere, and putting it into some other piping is not going to release as much intake manifold pressure as rapidly (the key to maintaining impeller RPM right? wrong?) as venting to the atpmosphere should. Therefore the turbocharger should have LESS work to do with an atmospheric valve installed.... And also I may be wrong and I too enjoy some construcive reproof and edification. And I am obsessed with cars / physics and turbochargers so I really should know all this already :schwitz:

note: no time to check for typos please excuse any

Manifold pressure is controlled with throttle plate, not with valve ;)

Compressed air will got between air filter and turbo's intake.

[Ball Bearing Turbo]

Sorry that's obviously true.... I'll be more cognizant of my terminology henceforth lol

[tristancliffe]

Yes, it's probably true that the atmospheric dump valve keeps the turbine rpms a bit higher...

As for having too much pressure when the recirc valve repressurises the system, I don't think that could happen. The efficiency of the recirc valves is low enough so that the pressure after recirc is less than it was before. But it's higher than if the pressure was just dumper to atmosphere.

So,
Atmospheric Dump Valve = higher turbine speeds maintained, but lower initial pressure
Recirculating Dump Valve = slightly lower turbine speeds, but higher initial pressure.

As far as I know, the recirc system means than when you get back on the throttle you have less lag and more power at that moment. Maybe, with modern smaller turbos and better flow in the systems the difference is minimal, but I reckon the lack of noise is worth at least a factor of two in the preference department. And I knew it wasn't the manifold pressure as such, but brain didn't engage fully :S

I love techie discussions like this - makes me go all gooey inside...

[JTbo]

As for having too much pressure when the recirc valve repressurises the system, I don't think that could happen. The efficiency of the recirc valves is low enough so that the pressure after recirc is less than it was before. But it's higher than if the pressure was just dumper to atmosphere.


Could be so, it was just what big boys has told me sometime and if not believing big boys, then who? :D

One nice thing to state is also that more Pressure does not make more power, usually jaws drop and eyes go wide, then ppl start to attack over you, how can you say such thing. Well thing is, more air = more power, so it is possible to get more power with less boost if you have bigger compression side of turbo, also less pressure is sooner available, this is often overlooked and only pressure is noted.

[Ball Bearing Turbo]

So,
Atmospheric Dump Valve = higher turbine speeds maintained, but lower initial pressure
Recirculating Dump Valve = slightly lower turbine speeds, but higher initial pressure.


Exactly what I was getting at - and as you alluded to further on in this post it probably depends on the equipment used and the total system as to whether or not there is a more effective method either way because the advantages of each offset the disadvantages of the other. Although I suspect that there is more stress on the impeller blades with a recirculating system... and more odd turbulence / wave energy interactions.... making the system inherantly unstable and subpar and likely to explode making a REALLY LOUD pshhh noise to make up for the lack of smaller ones...:schwitz: Ok OK fine that last bit is garbage....

And I knew it wasn't the manifold pressure as such, but brain didn't engage fully :S
Indeed .... I had tunnel vision about this valve discussion.

I love techie discussions like this - makes me go all gooey inside...

I must start posting more and lurking less I think I'll get a long with you guys well.... That Todd fellow makes my brain disintegrate though :razz:

[Ball Bearing Turbo]

Could be so, it was just what big boys has told me sometime and if not believing big boys, then who? :D

One nice thing to state is also that more Pressure does not make more power, usually jaws drop and eyes go wide, then ppl start to attack over you, how can you say such thing. Well thing is, more air = more power, so it is possible to get more power with less boost if you have bigger compression side of turbo, also less pressure is sooner available, this is often overlooked and only pressure is noted.

Eh? more air = more pressure = more power. Bigger compressor (big generalization without taking MANY things into account) delivers more air therefore greater pressure..... The more air you "compress" into a given volume, the greater the pressure in the volume. More air in given space = greater pressure.:tilt:

[JTbo]

Litres it is, you sure have more litres when you compress air, but you can get same amout of litres when compressing less, no need to go insane boost levels.

More air is not necessarily more pressure. However calculating this would be too difficult to me, but it is possible to calculate different cases where there is more efficent to use less boost and bigger compressor side.

Yes, there is all A/R things and such, but that will be perhaps too much to wonder in that area.

Compressed air warms up and this had something to do with this matter, can't remember all of this anymore as it is over a year when I did read story behind this all.

Anyway with 0.8bar boost two different turbos other gave more power than other, only difference was that other one had bigger compressor side/wings/chamber, eh I don't know exact term in english language, exhaust side was same, engine was same.

[wheel4hummer]

Just get a supercharger, then the boost is proportional to the RPM.

[JTbo]

Just get a supercharger, then the boost is proportional to the RPM.

Would be nice to have one in LFS, problem with suprerchargers is that they have habit of loosing efficency at higher rpm, would be bit different thing to drive :)

[Ball Bearing Turbo]

@JTbo

I'm not totally sure what you're saying......

In the example you're saying the two turbos yield the same amount of boost. And the engine with the larger compressor turbo, with the same amount of pressure, generated more power.

I would THINK that the amount of work required to create X amount of pressure (which is a function of the ambient pressure) would always be equal, so what you're saying must have something to do with the efficiency (specifically thermally) of the compressor, because (in essence of course) ENGINE X can make Y amount of power under Z intake pressure so long as the temperatures are the same, which you talked about.... SO we need to figure out why a bigger compressor creates a less heated charge. I was under the impression that the heat was due soley to compression however perhaps a smaller turbo requires more RPM to create a certain a mount of pressure and more friction is created therefore more heat.... Although a larger diameter impeller has more surface area..... SOMEONE HELP

[Ball Bearing Turbo]

Just get a supercharger, then the boost is proportional to the RPM.

I was thinking about this the other day....

It's very mountainous where I live, and even my city is very high above sea level.... Thus I can notice a sizeable difference when I go to the coast; I have more power by a wide margin that I can actually feel.

With a turbocharger, I would theoritically always have the same amount of power, since they are pressure regulated - even if it takes me a tiny bit longer to get full boost on a high mountain pass because the air is less dense. However with a supercharger boost must be proportional to the ambient pressure since it's driven directly from the engine... Correct?

[JTbo]

This is quote from one MR2 forum, where guys where thinking same thing very long time ago:
Think of it this way.
If Pam Anderson and and Arnold Schwarzenegger were both going to pick up a 50 lb weight ... who is most likely to struggle to pick it up and who could carry it further?

Also:
bigger turbo = more cfm = more air = more volume
so 15psi on a small turbo and a large turbo will put out different volumes of air which explains the power difference.

Most likely difference will come from air temp and therefore less oxygen in one unit of air, also part of thing could be that bigger turbo can carry to redline where smaller one looses more efficency at higher speed.

If I just would be able to find that article, I could link it, then it would be clear :)

[JTbo]

I did found another article, this information is against what I did read long time ago.
You can see from the formula above, at the same manifold pressure, the motor produce the same power regardless which turbos are used. That explains the misconception that at same boost, engine with bigger turbos pump out more power.

From URL:
http://cherrypicker.tripod.com/id7.html

Now I don't know what to believe anymore :shrug:

[JTbo]

I was thinking about this the other day....

It's very mountainous where I live, and even my city is very high above sea level.... Thus I can notice a sizeable difference when I go to the coast; I have more power by a wide margin that I can actually feel.

With a turbocharger, I would theoritically always have the same amount of power, since they are pressure regulated - even if it takes me a tiny bit longer to get full boost on a high mountain pass because the air is less dense. However with a supercharger boost must be proportional to the ambient pressure since it's driven directly from the engine... Correct?

You are very much right there.

I live around 100m from sealevel and I did test friends Subaru Turbo, it was suprising how much throttle it needs to go boost, even at 5000rpm it was not boosting in light acceleration, so I don't know if it helps in normal driving, 50% or more throttle would be needed with his car.

Other cars would be of course different.

I remember when some rally was placed very high on mountains and some rally drivers complained how those turbos go on like nothing and NA guys had less power, that was time when there was turbo and non turbo cars still racing together in same serie, good old times :)

[Ball Bearing Turbo]

The second one has to be right.

You may have something about them losing pressure at high engine RPM, but as the second article states - air pressure is directly related to air volume which is what I was poorly trying to explain above. The first article.... good greif:

bigger turbo = more cfm = more air = more volume
so 15psi on a small turbo and a large turbo will put out different volumes of air which explains the power difference.

that makes no sense whatsoever, it's not really a coherant statement I'm afraid.

EDIT brainwave (if I call it that - more of a relapse to think incorrectly...)
This may sound redundant - but I think that that guy was trying to say that air exits a turbo's compressor at a certain pressure (loud buzzer please) and therefore "more volume of 15psi" makes more power... I'm afraid not, pressure rises in the entire system as a gradual result of the hard work of our trusty impeller...

[tristancliffe]

A bigger turbo providing more boost (and hence more pressure) will allow the engine to generate more power, if the engine is capable of doing so. But, lag will be much much greater.

Often, it is better to use a smaller turbo, or even two smaller turbo's (either in series or parallel) with a different engine format. Most cars nowadays use relatively small turbo's for this reason.

Superchargers work in much the same way as turbos from a pressure point of view. The system is still pressure regulated (i.e. there should still be a pressure relief valve), although boost is proportional to engine RPM up to that limit. At higher revs they are indeed less efficient, and they also require more power to run - a turbo is driven by waste gas, a supercharger is driven by flywheel power....

With regards to the air heating with compression, it's a very real effect. The amount air heats up has to be seen to be appreciated. I've done some calculations in the past on a Starlet Turbo engine, and the turbo at peak boost will heat the air from ambient to about 150-200 degrees! The effect this has isn't so much on the density of air (although it is affected), but rather on the thermodynamic cycle. I'll dig out some graphs at some point over the weekend to explain what I mean, but basically it's beneficial to cool the compressed air. Hence an intercooler. But intercoolers massively increase the intake tracts, and have a massive effect on lag, so fitting a bigger intercooler for a given turbo size/engine performance will not necessarily increase power outputs.

It's a huge science, and thats why car manufacturers spend millions of pounds finding the right turbo (and ancilleries) for a given purpose. Someone who thinks they can bolt on, say, an HKS intercooler and expect it to work off the shelf is almost certainly deluded. Bigger isn't always better.

[keltern]

They sound silly however you play them. Might as well replace the pssshhhhhttt with riiiiicccceeeeerrrrrrrrfooooooooolllllll everytime they lift the throttle one iota.

:razz:

how can u adress people who like turbocharged cars ricers? ricers are jap cars, "riskokere" as we call'em in norway... :D faaaar from all of these have turbos, so how can you come with such a statement? i like a good bov-sound, cause it means POWER! ;) can't have big hp, for ex. 1000 hp, without some sort of bov! hehe!

i know, silly comment.. but don't use that RICER expression about a damn bov-sound... that's silly! :nod:

[tristancliffe]

You haven't read most of this thread have you. Do you think the Veyron goes pppsssshhhhhh when you move your right foot? No, I bet it doesn't. Does a standard Lancia Integrale go psssshhhhhhhhhhht when you twitch the loud pedal? No, it doesn't.

The thing is that the ONLY cars that gooo pssssssssssshhhhhhht are ricer cars. They might make that noise as standard, but thats because the manufacturers are trying to make them appeal to ricers. A powerful, standard road car doesn't burst your eardrums with some stupid noise every time your pulse moves the skin on your heel.

A loud ppsssssshhhhhhhhhttt DOES mean power, as you say. But it means 'listen to all this energy that I've just got rid of, so that my car goes a bit slower, cos I am a ricer and can't drive'. All the power is being wasted. Whats cool about that?

[keltern]

well, a lot of energy is dumped, i know that.. but by dumping the pressure, the turbo is still spinning when u continue after a gearchange or whatever.. if the pressure hadn't been dumped, the turbo would stop the second you let of the throttle! understand what i mean?

[tristancliffe]

Seriously, read this thread.

When you dump the energy, indeed the turbo is spinning under it's inertia. But when you open the throttle again, it has to start from scratch building the pressure, which slows the turbo anyway. Plus it takes time.

If you don't waste the energy (with a recirculating dump valve, as most manufacturers fit) then the turbo slows down a little bit more, but the boost pressure is regained much quicker (which also helps to speed up the turbo).

Really Keltern, if you ARE going to join a discussion a week late (nearly), then a) read it and b) avoid making silly comments that just show you haven't read/understood the previous posts.

[keltern]

:pillepall :D :thumb: yeye.. stop flaming! :razz:

well, i know that ALOT of the norwegian racers, and professionals involved in the bigger events, very rarely recurculates the pressure, they dump it.. and it works extremely well! :nod: you should check out this one: http://www.vsmotor.no/filmer.html

it's a bmw e39 m5, 3.8 straight six, with over 1100hp, and well over 1100 nm. awesome ride! and NOT a ricer.. :thumbsup:

download a couple of the vids, and see if you could make this car go better! :thumb:

[tristancliffe]

Again - READ THE THREAD!!!!

For motorsport it's different. You are going from 100% throttle to 0 throttle. Engine Revs are much higher, and drivability is less of a concern (i.e. it doesn't matter how smoothly the turbo kicks in). In those situations atmospheric dump valves are used to keep the turbo from stalling, knowing that in 4 secs time you'll be at full throttle again.

A road car spends only a tiny amount of time at WOT. Therefore, what little boost you have needs to be kept, and everything must happen smoothly, as the majority are car drivers don't have sufficient skills to manage.

If you'd read the thread you'd have read this already. I'm not needlessly flaming, I've told you twice before to read it, and you still keep trying to post things you think we've overlooked.

I will however download the videos. Not to see how fast they go (anyone can go fast with power - it's not a skill), but to see if the BMW's have indicators. Why don't drivers of German cars use them? Ever!

[keltern]

yeah, ok.. i'll admit that i didn't read the entire thread... but LFS is racing, not common road driving! =) so why talk about smooth driving for the common people! =)

and hey, one skill you didn't mention, was controlling power! hehe! that's what you'll see on the vids.. =) he's playing around on these ones, but i think he's a driver in gatebil extreme as well, so he knows how NOT to make the wheels spin also... ;)

[tristancliffe]

Yes, but this thread was kick started by someone saying a dump valve is the best sound a car can make. He was almost certainly referring to road car noises, so thats what this topic focussed on.

And that driver looked rubbish. Terrible lines, could barely control the oversteer when he spun the wheels. And what a pointless car - having 1000hp is stupid if you can't put in on the road. I bet that car would do quicker lap times with less than 500hp, would use less fuel (so would do better in endurance racing), and would eat less tyres. Maybe I've missed the point of stupidly powerful cars like that, but to me, a purist, it's just silly.

[keltern]

you don't like to have fun do you! hehe! he wasn't trying to get low laptimes ffs! you should know that just by looking.. btw, that's norways fastest roadgoing car.. :)

[tristancliffe]

Yes, and I bet many other road cars would get faster laptimes. Being fastest doesn't mean quickest. I'd be pretty sure that a 200hp Seven would be quicker round most tracks.

[keltern]

i wasn't saying he has the fastest car around a track.. but u only hear what you wanna hear, so.. ;) you should try looking for more norwegian streetcar vids, cause there are sooo many fast and fun cars to check out, not that i think you'd bother, but worth mentioning...

the meaning of my posts, was not to use blurp out RICER everytime someone mentions something turborelated.. :)

[tristancliffe]

I don't blurp out ricer when ever turbo is mentioned.
I do blurp out ricer when people say dump valves are the best sound ever, or if someone tries to show me a 1000hp BMW. :nod:

[keltern]

lol i tell you! ;) what's so jap (or ricer as u call it..) about a 1000hp BMW?

[tristancliffe]

Because, for all that power, it's not a quick car. It's got a powerful engine, but not enough grip. They've done it not to be fast, but to show off.

Showing if is what ricer is all about. That BMW = 100% Rice. :D

[keltern]

hehe! yeah, you're right about showing off.. but i really don't like the ricer-expression.. and it really doesn't fit the bmw! hehe! for me, a ricer is a overstyled car, most likely a jap car, not a hugely fun bmw! :)

[tristancliffe]

Clearly we're not going to agree here. I don't like rice, and I don't like stupid overdone BMW's that aren't much fun to drive. You can if you want to though.

[keltern]

hope so.. hehe! what's your definition of rice btw? ;)

[Ball Bearing Turbo]

Perhaps we need a clear definition of "rice"....

"A cereal grass (Oryza sativa) that is cultivated extensively in warm climates for its edible grain.
The starchy grain of this plant, used as a staple food throughout the world. "

Or perhaps a car referred to as "rice" has been previously "riced":To sieve (food) to the consistency of rice.

Which is somewhat fitting of cars with many small fragments glued on such as "roof scoops" (note that scoops are often employed in the portioning of rice... ironic? I think not)

Anyhow, Tristan are you saying then that you concede atmospheric style BOVs are better for pure acceleration - seeing as how they are used extensively in motorsports? And your point is simply their application in street cars is not necessary for everyday drivability (although better for "pure performance and nothing else")

[tristancliffe]

Erm, there is no FIXED definition of rice. The parameters are flexible depending on what other paramaters there are.

If a car has a silly body kit on it, regardless of if it's useful, and is used on the road = Rice
If the car has a silly body kit on it that probably wouldn't achieve anything, and is used on the track = Rice
If the car has far too much power compared to it's grip = Rice
If the car has far too much grip for it's power = Rice.
I could go on for hours. It's the thing considered as a whole for me, and my Rice 'limits' are probably a lot lower than most people (i.e. I think something is 100% rice that most people think is sound engineering or proper race technology).

[tristancliffe]

Perhaps we need a clear definition of "rice"....

"A cereal grass (Oryza sativa) that is cultivated extensively in warm climates for its edible grain.
The starchy grain of this plant, used as a staple food throughout the world. "

Or perhaps a car referred to as "rice" has been previously "riced":To sieve (food) to the consistency of rice.

Which is somewhat fitting of cars with many small fragments glued on such as "roof scoops" (note that scoops are often employed in the portioning of rice... ironic? I think not)

Anyhow, Tristan are you saying then that you concede atmospheric style BOVs are better for pure acceleration - seeing as how they are used extensively in motorsports? And your point is simply their application in street cars is not necessary for everyday drivability (although better for "pure performance and nothing else")

No - the atmospheric dump valve is better on high performance turbos (i.e. turbo's that have to do a lot of work, say on a restricted engine) when used on a track or rally stage, and a very large proportion of time is spent at either full or zero throttle.
A recirculating dump valve is better on lower stressed turbos (say a small turbo on a Huge V8 with very little restrictions on air flow), or on 99.9% of cars on the road (stock or modified) as they spend over 95% of the time at part throttle.

But as with most definitions, there are exceptions to either rule, so to anyone who subsequently posts a pic of a Bi-Turbo Fiesta 998cc, it proves nothing.

[Ball Bearing Turbo]

If a car has a silly body kit on it, regardless of if it's useful, and is used on the road = Rice
If the car has a silly body kit on it that probably wouldn't achieve anything, and is used on the track = Rice


Interesting: :scratchch
So then if one only owns one car, and he uses it on the track as well as a daily driver... then if the car has an appropriate body kit that actually helps on the track, it would be referred to as rice on the street but not on the track, making a type of "rice Jekyl & Hyde" scenario, where the car switches designations on the way into and out of the track.... :razz:

hehehe

EDIT before you post it, I know you said the parameters are flexible - I was just solidifying some of the ramifications of that philosophy....

[tristancliffe]

Yes - but who, in their right mind, drives such a car?! Most race series that would be useable on the road (unless so far off the pace) don't allow bodykits and silly things. But it would be funny - I'd chat to him happily in the paddock about his car, but as soon as he went on a public road with it, I'd point and laugh until he hit me.

[Ball Bearing Turbo]

A recirculating dump valve is better on lower stressed turbos (say a small turbo on a Huge V8 with very little restrictions on air flow), or on 99.9% of cars on the road (stock or modified) as they spend over 95% of the time at part throttle.


I am not trying to drag this out or seem dense but I still don't understand exactly why you feel this way... And if you're right I really want to understand this. Here are some things I fail to comprehend::schwitz:

A) What does does spending 95% of your time at part throttle have to do with your dump valve?:shrug:

B) How does the restrictiveness (word??) of the engine affect the dynamics of how well either method performs?

[Ball Bearing Turbo]

Yes - but who, in their right mind, drives such a car?! Most race series that would be useable on the road (unless so far off the pace) don't allow bodykits and silly things. But it would be funny - I'd chat to him happily in the paddock about his car, but as soon as he went on a public road with it, I'd point and laugh until he hit me.

LOL :D

I guess you don't get up to downforce inducing speeds really in autocross events :scratchch Perhaps a 45 degree spoiler... :tilt:


But I was referring to someone that drives their car everyday and takes it to the track on the weekend for some fun - not necessarily driving a WRC car on the road (although that would be fun come on)

[tristancliffe]

Well, if your car is meant to be used at WOT lots, then the turbo will be lighter, and freer flowing etc etc. You know the driver will be going from full throttle to no throttle to full throttle.

On a road car, the periods of full throttle are small. So when the driver gets some boost, then lifts, it's unlikely he'll be going back to full throttle. Therefore you use a recirculating dump valve - this means that what little engery you've managed to build up isn't just chucked out of the car needlessly.

The restrictiveness is probably the wrong word. A WRC engine is restricted via a plate somewhere (I forget exactly where, but that's not important for this discussion) in the induction system. So the turbo is designed very differently to a non-restricted engine, simple because the maximum air flow of the system is very different. A larger engine like a Big V8, will have much less breathing problems that a small WRC engine, and that needs to be taken into account of (on top of trying to match the turbo to the power you want, where you want it, what type of driving it'll do etc etc).

Turbo's and their related components are huge sciences. Anyone who looks in a catalogue for Supra Turbo kit, and expects it to work with the rest of his system from a different catalogue, or not exact spec, is deluded to some degree. But being deluded is a necessity for ricing.

But I was referring to someone that drives their car everyday and takes it to the track on the weekend for some fun - not necessarily driving a WRC car on the road (although that would be fun come on)Well, thats a different matter. If they used it primarily on the road with a silly body kit then it's rice. If that rice-mobile goes on a track for a track day, then it's still rice. All because of the PRIMARY reason of the car.

[nikka]

A road car spends only a tiny amount of time at WOT.
MUHAHAHAHA! If you're ever in Norway, give me a call and I'll give you a ride to show you "tiny amount of time at WOT" :smileypul

(but no, I dont care about that stupid "ptttsshhhhh"-sound, so i've got no BOV)

[tristancliffe]

Seriously - if you add up every throttle opening you ever do, I bet it's only a tiny amound overall at WOT.

Hell, most of us here (that can drive in real life) probably drive more spiritedly than most drivers, but still, a surprisingly small amount of total time is spent at WOT. Unless you are either a complete idiot with no disregard of others, have your own private race track/road/dirt track, or you live slap bang in the middle of nowhere, about 200 miles from the nearest other house.

[wheel4hummer]

The only downforce that bodykits make is static downforce. :nod:

[vari]

Erm, there is no FIXED definition of rice. The parameters are flexible depending on what other paramaters there are.

....
If the car has far too much power compared to it's grip = Rice
If the car has far too much grip for it's power = Rice.
...


For me personally, a purist if you may, that's not the case. I approve any modification as long as it improves performance. That is usually the goal, right? That beamer makes a faster laptime than a stock one and therefore doesn't fit my idea of rice. :shrug: It's handy too, I don't have to explain why a WRC car isn't rice and something else that is similar is.

I guess we both can agree though that a 37hp Daihatsu Charade 1.0L 3 cyl diesel on hybrids isn't rice? It doesn't have too much power nor too much grip :D

[tristancliffe]

I guess we both can agree though that a 37hp Daihatsu Charade 1.0L 3 cyl diesel on hybrids isn't rice? It doesn't have too much power nor too much grip :DDepends what the owner has done to it. Some stick on carbon fibre plastic, window tinting, bodykit, pointless huge alloys - they'd all make it rice.

[Ball Bearing Turbo]

For me personally, a purist if you may, that's not the case. I approve any modification as long as it improves performance. That is usually the goal, right?

Indeed this tends to be my stance also, and Tristan has stated himself that his standards for "rice" are less tolerant than most.... His definition by nature is dynamic, I prefer the simplistic definition you alluded to above...

[al heeley]

Geez, I'm glad you guys managed to steer this one back onto topic.....:razz:

[tristancliffe]

We went from off topic, back to topic, off topic again, and now a discussion on whether it's on or off topic, which must be neither and both at the same time.

*then the universe imploaded in a burst of logic*

Douglas Adams rocks

[Ball Bearing Turbo]

Well now the topic is the topic, just the context of the topic has changed... Seems like Al is trying to apply a "topical solution" to our debate....

[al heeley]

Sorry, what was the question? :D

[Fonnybone]

If a BOV goes off and no one is around to hear it, does it make a sound ? :scratchch :schwitz:

[tristancliffe]

How many blow offs can a blow off valve blow if a blow off valve could blow valves? :schwitz:

[JessesAE86]

A blow-off valve is the silliest noise that a car can do. Why waste all that compressed air by making a pointless and power reducing noise? Why not get a silent recirculating dump valve, make less noise (and therefore look less like a complete idiot who likes 'phat carz') and actually go faster too.

This does not apply so much on a race circuit where you want to keep the turbo spinning as fast as possible, are using high engine revs and WOT most of the time, so boost build up is very rapid. Much like WRC cars. Which is why they make that silly noise, and makes the cars sound like malfunctioning toys.


umm actually thats why rally cars have Misfire Anti-lag System

Since you obviously dont know it basically is inducing engine misfire under deacceleration, which is why boost pressure is maintained resultlting in quicker acceleration which is why most if not all rally cars use this, (well last time i checked they did)

[JessesAE86]

Well, if your car is meant to be used at WOT lots, then the turbo will be lighter, and freer flowing etc etc. You know the driver will be going from full throttle to no throttle to full throttle.

On a road car, the periods of full throttle are small. So when the driver gets some boost, then lifts, it's unlikely he'll be going back to full throttle. Therefore you use a recirculating dump valve - this means that what little engery you've managed to build up isn't just chucked out of the car needlessly.

The restrictiveness is probably the wrong word. A WRC engine is restricted via a plate somewhere (I forget exactly where, but that's not important for this discussion) in the induction system. So the turbo is designed very differently to a non-restricted engine, simple because the maximum air flow of the system is very different. A larger engine like a Big V8, will have much less breathing problems that a small WRC engine, and that needs to be taken into account of (on top of trying to match the turbo to the power you want, where you want it, what type of driving it'll do etc etc).

Turbo's and their related components are huge sciences. Anyone who looks in a catalogue for Supra Turbo kit, and expects it to work with the rest of his system from a different catalogue, or not exact spec, is deluded to some degree. But being deluded is a necessity for ricing.

Well, thats a different matter. If they used it primarily on the road with a silly body kit then it's rice. If that rice-mobile goes on a track for a track day, then it's still rice. All because of the PRIMARY reason of the car.


LOL you are hilarious, you really know nothing more than the common ricer about turbos, LOL

[tristancliffe]

umm actually thats why rally cars have Misfire Anti-lag System

Since you obviously dont know it basically is inducing engine misfire under deacceleration, which is why boost pressure is maintained resultlting in quicker acceleration which is why most if not all rally cars use this, (well last time i checked they did)

The anti-lag system is separate from the blow off valve - extra fuel is ignited in the exhaust manifold to keep the turbo spinning. But prior to anti-lag being in WRC, you might have noticed the turbo cars going ppssssssshhhhhhtt.

So they used to use atmospheric blow off valves
Now they use atmospheric blow off valves and an anti-lag system.

[al heeley]

ZZZZZZZZzzzzz.......
Please wake me when you have finished playing Boring-Car-Fact-Trivia Top Trumps with eachother. :scratchch

[DejaVu]

'listen to all this energy that I've just got rid of, so that my car goes a bit slower, cos I am a ricer and can't drive'.
:pillepall

Not true, i know loads of people with sapphire cosworths (rwd) who could put a lot of track drivers to shame with there skill behind the wheel, just because some one is a ricer doesn't mean they can't drive.

[tristancliffe]

:pillepall

Not true, i know loads of people with sapphire cosworths (rwd) who could put a lot of track drivers to shame with there skill behind the wheel, just because some one is a ricer doesn't mean they can't drive.

Hugely major exception, rather than the rule.

[JTbo]

What will be valve that has both, athmospeheric and recirculation functions :scratchch

Those do exists as last week I saw them on sale, it is quite clever thing actually, during normal driving you get that quiet action and on track all that pssshhhshs and boo you need :D

Sorry, I better go back to packing my stuff and moving to new apartment ;)

[tristancliffe]

What will be valve that has both, athmospeheric and recirculation functions :scratchch

Best of both worlds I guess. I have no experience with combined dump valves, so it's merely conjecture.

[Ball Bearing Turbo]

What will be valve that has both, athmospeheric and recirculation functions :scratchch

Those do exists as last week I saw them on sale, it is quite clever thing actually, during normal driving you get that quiet action and on track all that pssshhhshs and boo you need :D

Sorry, I better go back to packing my stuff and moving to new apartment ;)

It must be brown rice... better for you but still rice? :razz:

Sounds like a good idea though

[spoop]

BMW sells a pre-riced car...its called the M6. Its got power, if you pull over, twist a few knobs and press a few buttons, but is crap at the track.

[VTcommodore]

Erm, there is no FIXED definition of rice. The parameters are flexible depending on what other paramaters there are.

If a car has a silly body kit on it, regardless of if it's useful, and is used on the road = Rice
If the car has a silly body kit on it that probably wouldn't achieve anything, and is used on the track = Rice
If the car has far too much power compared to it's grip = Rice
If the car has far too much grip for it's power = Rice.
I could go on for hours. It's the thing considered as a whole for me, and my Rice 'limits' are probably a lot lower than most people (i.e. I think something is 100% rice that most people think is sound engineering or proper race technology). So ur saying that robbie bolger from OZ who drifts the CAPA Drift ute drives rice cus of its excessive over powered engine ( cranks way over 1200RWHP )that just turns the rear tyres into a pile of dust and smoke by the end of a lap.
U try calling his Ozzie drift ute rice and i dont think you would be typing for a while buddy, oh btw i agree with sum of the above terms except for 1.
http://www.capadrift.com.au (http://www.capadrift.com.au)
thats a link if u wanna put ur comments away for a while

[tristancliffe]

Drift = Rice. It's all about showing off. Sure there is a bit of skill in drifting, but at the end of the day it's all about visual thrills, and is therefore rice.

[Hankstar]

If the car has far too much power compared to it's grip = Rice

Not if it's a pre-1968 F1 car :nod:

But you're talking about street cars, so I'll just put my 2c back in my pocket :)
Although here's another criterion for your list: any car driven by a P-plater with a FOR SALE sticker and mobile phone number on it and which has been so pimped that it's resale value is in the trash, it's rice :D

[VTcommodore]

Drift = Rice. It's all about showing off. Sure there is a bit of skill in drifting, but at the end of the day it's all about visual thrills, and is therefore rice. So ur calling a 6.0L LS-1 Cast Block V8 a rice blower. LOL u should leave ur computer once and a while and smell the burning rubber and high octane fuel once and a while.
Aussie muscle dusnt take the branding of as u guys call " RICE".

LOL You can tell that sum people know nuthn about Aussie cars.

[VTcommodore]

Not if it's a pre-1968 F1 car :nod:

But you're talking about street cars, so I'll just put my 2c back in my pocket :)
Although here's another criterion for your list: any car driven by a P-plater with a FOR SALE sticker and mobile phone number on it and which has been so pimped that it's resale value is in the trash, it's rice :D
LOL hahaha its not rice buddy its not even capable of blowing little grains out the exhuast after an aussie P plater has done with it LOL.
Therefore its ready for the scraping yards or maybe strip it at pick and pay-less cuts.

[tristancliffe]

So ur calling a 6.0L LS-1 Cast Block V8 a rice blower. LOL u should leave ur computer once and a while and smell the burning rubber and high octane fuel once and a while.
Aussie muscle dusnt take the branding of as u guys call " RICE".

LOL You can tell that sum people know nuthn about Aussie cars.

Yes, a 6 litre V8 could be rice. I don't know that car/engine specifically, but chances are, if they speak like you, it is rice. Do you know what Octane means?

Yeah I admit I know nothing about Aussie cars, but to be honest who would want to outside of Australia? They're nearly as bad as American cars.

[VTcommodore]

And Also to answer the other question, yes i do know what it is. Octane in the term of fuel for racing fuels ( being high octane ) Just describes how quick the fuel burns.
The higher the rating, the slower and more controlled the fuel burns.In OZ we just got shell 100 Octane yay. This allows its use in high compression engines. So see Im not an idiot buddy.

[tristancliffe]

Wrong. Try again.

[VTcommodore]

Wrong. Try again.
Well comon MR forum post up im getting tired tell me before i go to sleep

[tristancliffe]

Thisnameistaken was close. :p

The octane rating of a fuel is it's resistance to knocking. Most octane numbers are RON (Research Octane Number, a low to medium load test), but some countries (mainly the states) use MON (Motor Octane Number, a high-load test). It's basically a comparison to a control fuel (isooctane I think). Race fuels can have a RON of greater than 100 simple because isooctane isn't the most knock resistant fuel. In turn, knocking is the situation where the pressure ride during compustion is exceptionally high (high enough to damage components), it's not the same things as pre-ignition, although knock can induce preignition, and vice versa. Both are bad for engines, but combined you'd wreck an engine in minutes. Just having the RON number or the MON number doesn't tell the whole story though: RON - MON = Sensitivity, which represents the fuels ability to cope with multiple scenarios.

Tetra-Ethyl Lead is an octane booster, but since leaded fuel is widely out of use, alternatives have to be used.

What you thought was Octane VTcommodore, was the measure of volatility of fuel, and has nothing to do with octane.

[al heeley]

I love these BOV posts, they all seem to go the same way.........:x

[Ball Bearing Turbo]

I love these BOV posts, they all seem to go the same way.........:x

Must be from all the hot air that BOVs release.....:D

[wheel4hummer]

6.0L LS-1 Cast Block V8

I thought an LS1 was 5.7L! :scratchch

[Scirocco]

I thought an LS1 was 5.7L! :scratchch
Just because some of them are doesn't mean that all of them are. :pillepall Try looking at some GM crate engines online to see what's available....

[klbbadd2002]

:scratchch If im not mistaken, The topic of the thread has to do with a new
BOV sound. I suggest to just lock this post if this stupid shit keeps
going on.:pillepall




Drift or DIE

[lrdbsi]

They sound silly however you play them. Might as well replace the pssshhhhhttt with riiiiicccceeeeerrrrrrrrfooooooooolllllll everytime they lift the throttle one iota.

:razz:
any car that dumps compressor pressure isnt a ricer, FOOOOOOL, meh try going ina turbo car in real life,

[lrdbsi]

Drift = Rice. It's all about showing off. Sure there is a bit of skill in drifting, but at the end of the day it's all about visual thrills, and is therefore rice.
omg dude, wat a pussy, drift is an art form and was actualy done to get u round a corner faster while loosing traction, i think ur an idiot cause u dont know the meaning of rice, rice is a nissan pulsar with spinner-hubs and neon lights( something that ud drive ) drift is ****ing badass and respect to anyone that can drift good in real life, TRISTIAN i suggest u shut up cause ur loooking reall nooby dude, meh pussy u are

[al heeley]

lrdbsi: if you continue to drag every topic down to the purile level of arguing about the merits of drifting, or continuing to insult other members because their opinions differ from your own adolescent opinions, then please don't bother posting on this forum any more.
Can we get back onto topic?

[tristancliffe]

Simply a reply, without being dragged down to anyones level in particular...

Yes, I have been in several turbo cars. Some were quite nice, others (mainly the 4WD ones) were dull. A Mitsubishi Lancer Evo round an autocross track was quite good fun though, which surprised me, as they're dull on the road.

As for drifting, the only time I've drifted was when I've made a mistake. I know that losing traction means you go slower round corners except on very tight corners (i.e. quicker to 'drift' round a cone than to drive round one).

You know my opinions on drifting anyway, so I'm not going to be dragged down into ar argument about it. But it's all based on fact.

And finally, I would never even get into a car with neons or spinners, let alone own one. So before trying to stereotype me into a certain catagory, it might be worth reading some of my posts so you can gain an understanding of my views on cars and the science behind them.

There, success. I don't think I was offensive.

[wheel4hummer]

Just because some of them are doesn't mean that all of them are. :pillepall Try looking at some GM crate engines online to see what's available.... Well, I don't think you could "create" 0.3L more displacement just by porting the heads, manifold, and getting new internals. If you got low-compression pistions, then it might increase the displacement. :shrug:

EDIT: I meant the 3rd generation ls1 :D The aussie LS1 is 6.0L :P

[keltern]

really can't stand tristan.. maybe we should just ignore him from now on? :scratchch

"that car is rice.. that guy is rice... this whole damn UNIVERSE is RICE!" :D

[Matrixi]

Sorry for offtopic again.

Calling drifting as rice is the same as calling racing as rice. Both do count as motorsports even though you might deny it yourself. The actual meaning of word "rice" has really gotten messed up in some peoples heads. I do honestly think gripping requires more skill (in LFS) than drifting, but I find them both entertaining and fun. Having the ability to master them both is what counts. :)

I know this forum is all anti-drift, and therefore I'm on my way to get my flameproof suit out from my wardrobe :schwitz:

[motary]

Drifting is more exciting from my perspective, since both cars on the edge of losing control, drifting cars mainly these days dont have what you in america call bodykits, they have aerokits, I suppose the WRC kit that M-Sport sells for Focus is rice, too?

Pardon me sir, but if you don't like what we do, go do whatever you like to do.

I'm sorry for offtopic >.<

[Ball Bearing Turbo]

... For a forum against drifting, we sure do a lot of drifting off topic hehe (lighten up everyone LOL)

[neRu]

How i imagine it works:

No BOV:
The turbo no longer has driving force, so it slows down very fast, because the air is getting hard to compress:
http://img23.imageshack.us/img23/8046/nobov1by.jpg

Open BOV:
The turbo no longer has driving force, so it slows down when it compresses air. Now we have a thing to prevent the turbo from slowing down as fast, and not get damaged, the BOV's spring is set, so the spring just exactly can overcome the force of full boost when driving, and when you close throttle, the pressure gets to high, and the BOV opens. Because the turbo doesn't stop, there is faster pressure-buildup when you open the throttle again. The disadvantage is, that it still has to deal with vacuum on the intake-side.
http://img23.imageshack.us/img23/7476/openbov3sh.jpg

Recirculating BOV:
The turbo no longer has driving force, so it slows down. This time it opens and vents out into the intake-side. The air expands, as it is no longer under pressure. Some gets out through the airfilter, and might be heard as a faint whistle, whilst some gets sucked through the turbo again, and recirculated. The turbo no longer have to deal with the vacuum on the intake-side, and will maintain turbinespeed a little longer time, which usually comes in handy when you open the throttle again.
http://img26.imageshack.us/img26/2738/recircbov5kc.jpg

My nickle

[tristancliffe]

And what a good nickle :D

[neRu]

Thank you

[Ball Bearing Turbo]

Nice diagrams!

But there's no way in the physical universe that 99% of the air isn't going to escape out the air filter under pressure. Also, if you impose more work on the impeller to recirculate air that's any MORE dense that atmospheric, that's more drag to slow the turbocharger down, not less! Air will take the path of least resistance and therefore would rather escape via the air filter than impose work back on the impeller itself. Plus this effect would temporarily screw up the airflow before the turbo just to top it off, rendering your well R&D CAI flow characteristics futile for a second. For these reasons I submit that atmospheric BOVs maintain the least drag on the turbocharger when transitioning from boost conditions to lower/closed throttle conditions, and provide a quicker transition back the other way.

[Warper]

I thought "rice" is something to eat... will think about it :shrug:

[neRu]

Nice diagrams!

Thank you too.
What you say, makes sense if i think about it, because it would reverse the airflow on the intake side for a fraction of a second or more, and then when you step on it, the airflow have to be turned around once more.

If it was me, i'd choose an open BOV, no matter if it was a roadcar or racecar. If i can spare some money, i think that i'd buy one, and put it on my turbo-project car, a Saab 90 from 1985 :D

Just too hear your opinion, which place would be the best to put the intercooler, before the turbo intake, or between the outlet and manifold - aka the pressure side - on the turbo?

My opinion is, that it's best to place it before intake, because if you compress, for example, 20 degrees celcius air to 1 bar, then the temperature would rise to 40 bar, still just an example, may not be the correct temperature-change, then you'll have to take twice the amount of heat/joules out of the air, than if you'd put it before the turbo.

It's just a thing that i've been thinking about.

[tristancliffe]

You have to put the intercooler AFTER the turbo.

air into turbo = 20 degrees C
compression ratio = 2 (so 2 bar output)
air out of turbo = ~150 degrees C (yes, it can be this high, and often higher)

If you cool PRIOR to the turbo, and have an Air_in temp of say 10 degrees, it'll still be 145 on the outlet.
But if you cool after the turbo you'll have air at about 60 degrees going in (depending on air flow, area, colour, material etc of intercooler).

[Ball Bearing Turbo]

Tristan beat me again - our modem was down at work some I am way behind now. Oh well.

And yes it must go after the compressor of course. Heat exchange is way more efficient this way since the compressed charge is so hot. Cooling off ambient air with ambient air doesn't really work (assuming air to air intercooler) there is not much temp difference. Intercoolers are for cooling a hot, compressed charge before combustion, as explained by Tristan.

Back to the issue at hand, if what I said WASN'T true, then vehicles in motorsports wouldn't use atmospheric BOVs, plain and simple. I suspect the only reason recircs (which probably don't really do much recircing incidentally) were invented was to make the average passenger car silent. But who cares about that really now....

[tristancliffe]

Can you remind me what your current point is, as I've lost it in the miriad of posts above :p

[Ball Bearing Turbo]

UH ok.

I think you're just mad that I am right heheheehhe

My point through out this entire thread is to quench the fallacy that atmospheric BOVs are "rice", as stated by you. They do have a meaningful purpose and are not simply for show because they do increase performance, perhaps only slightly.

Read my previous post on the issue (the post before the intercooler intermission), and then you can come back and concede graciously.....

[tristancliffe]

I think what you forget is that air has a considerable momentum, so for the fraction of a second that all the valves are closed, the air still carries and on and compresses due to it's own mass.

Also, with a recirc valves, the air tends to go round the loop over and over again (obviously losing pressure each time in the loop, but not as much as it it was vented straight to atmosphere, whilst the excess excess (yes, two excesses) goes out of the air filter) Some air will come out of the air filter, although I doubt you'd here it over an engine and road/wind noise. And yes, I agree the pressure will slow the turbine down quicker than if it was an open valve. But when you reopen the thottle, and the pressure can be used immediately, but with the open valve the turbo has to do all that work all over again.

I still believe that for road use a recirc valve is better, and for motorsport an open valve is better (although not one that is designed to make a loud noise). Sure an open valve is better than nothing, so I'm not saying it's useless with one, just that the car would be better on the road with a recirc one.

And the MAIN reason rices have open BoV's is because of the silly noise they make anyway...

Edit: I'll never concede graciously :p unless you prove me wrong!

[Ball Bearing Turbo]

I have a hard time thinking that much air would be inclined to travel the recirc loop. The problem is that it's pressurized, and I seriously doubt that the momentum of incomming air would be enough to offset the desired release of pressure. One could calculate the amount of force air at sea level would exert when moving at say 400CFM, and see how much inertia that air would carry - I bet not a lot compared to 10PSI attempting to escape... I think you are forgetting that the compressed air wants in a bad way to leave the system, it's not going to gleefully continue running a loop that it can easily escape just for our benefit...

As far as hearing it, my boss has a PT Cruiser Stage 1 with a recirc valve, and part of the stage one is a CAI. Before the CAI I couldn't hear too much from the BOV, but now that the CAI is installed and the stock maze "see if the air can find it's way in" airbox is gone, I can hear the BOV almost (not quite) as loud as the SRT-4 (open BOV)I had a spin in a couple weeks ago. Lifting the hood and blipping the butterfly valve in the throttlebody by hand yeilds being able to feel the blow-out from the air filter if you rev it a little.

I agree with you that open BOVs are probably installed for the wrong reasons lots of times... but that leads to a point of difference between you an I: my definition of rice is static, yours is dynamic....

Besides, you started in this thread by saying open BOVs reduce power output didn't you? Or was it just wasting the potential energy in the form of compressed air that you were against?

[tristancliffe]

Yeah, not reducing power from stock, just not providing as much power as optimum. And doing ANY mod to ANY car for the WRONG reasons (i.e. BOV's cos of the noise, or lowering it cos of the looks) is rice in my opinion :P

I've never had a ricing accusation turn into such a good, civilised, interesting conversation though :up:

[L(Oo)ney]

interesting conversation

http://lcb.me.uk/losingit/wp-images/smilies/icon_sleepy.gif

Huh? What?

http://www.animepaper.net/smilies/sleeping.gif

[vari]

Atmospheric BOV is a bad idea if you're running standard mass airflow sensor. The engine will run rich when the throttle is closed and that can cause backfiring and even stalling because the air that was read by MAS never went in.

In such case it's definitely rice imo :)

[tristancliffe]

But if you put the MAS downstream of the BOV would that not cure it? Then it would only 'sense' the air going into the engine? I don't really know how they work so it's just speculation.

And far be it from me to try to justify something someone else has called rice :p

[Ball Bearing Turbo]

The MAF is not affected by changes in air pressure. Which is precisely WHY it's called a "mass airflow sensor"! It measures mass, pretty much regardless of temperature or pressure.

Besides that, even if that false notion was true, you could use MAP sensors instead anyway and thus would always calculate the correct air/fuel ratio - but MAFs work fine.

Think about where MAFs are located... If there's no air flow there is no fuel, pure & simple.

I've heard this argument before and it makes no sense.

Next.

[Ball Bearing Turbo]

Yeah, not reducing power from stock,

Ok.... :thumbsup:
just not providing as much power as optimum.
Pardon?

Could you rephrase this paradox you created?

And doing ANY mod to ANY car for the WRONG reasons (i.e. BOV's cos of the noise, or lowering it cos of the looks) is rice in my opinion :P

I half agree I guess. :scratchch We've been there before though so I'll leave it at that. Or will I? :Looking_a Don't you like things that happen to be functional even though they look nice? Are all forms of art rice in your view? All music / art / anything aesthetically oriented, according to what I've heard from you, is therefore pointless and frivolous and rice... Don't you have any fun man? LOL :tilt:

I've never had a ricing accusation turn into such a good, civilised, interesting conversation though :up:
Thanks Tristan although apparantly some people are bored... :shrug: :pillepall

[tristancliffe]

Could you rephrase this paradox you created? Well, why fit an open BOV and get "x" spread of power, when you could fit a recirc BOV and get "x + a bit". It's like sacrificing some performance for what in my mind is a silly noise.

I half agree I guess. :scratchch We've been there before though so I'll leave it at that. Or will I? :Looking_a Don't you like things that happen to be functional even though they look nice? Are all forms of art rice in your view? All music / art / anything aesthetically oriented, according to what I've heard from you, is therefore pointless and frivolous and rice... Don't you have any fun man? LOL :tilt: Hell yes, looking nice is important. But I'd rather have functionality over looks any day, and I wouldn't sacrifice fuctionality or performance just for aesthetics. Hell, I drive an MX-5 - I know all about sacrificing image for ability :shy: But people who lower their car BECAUSE it looks nice, forgetting the pros and cons of the vast majority of bolt on lowering kits, rather than lowering it properly with all that entails for any performance benefits and then being pleased when it happens to look lower annoy me. Ricers don't walk into a shop and say I want to improve the suspension geometry on my car to enhance traction, despite the expense in handling (or whatever that particular component might do). They ask specifically to lower the car by 2 inches, paying little or no regard for what will happen when they do so.

[vari]

I've heard this argument before and it makes no sense.Next.

You probably have because it's on hundreds of pages, here's couple:

http://features.evolutionm.net/article/projectevo/22
http://www.automotiveforums.com/t272165.html
http://www.dsmtuners.com/forums/showthread.php?t=130193&goto=nextoldest
http://www.ls1tech.com/forums/archive/index.php/t-126223

It makes sense to me, there's still airflow when the throttle is closed and the bov is opened.

Think about where MAFs are located... If there's no air flow there is no fuel, pure & simple.

Where do you think it's located then? The one I'm talking about is in the airbox or directly after it. ( http://www.evilution.co.uk/info/turbo.jpg )

Thanks Tristan although apparantly some people are bored...

If this was directed at me, care to explain? :)

[Ball Bearing Turbo]

If this was directed at me, care to explain? :)

No sir, it was I think LOoney who had some sleepy faces posted when Tristan commented on the discussion being interesting hehe

Thank you for joining the discussion, more input is always better!

I will address the rest of the post later I too much work to get done first!:schwitz:

[Ball Bearing Turbo]

Well, why fit an open BOV and get "x" spread of power, when you could fit a recirc BOV and get "x + a bit". It's like sacrificing some performance for what in my mind is a silly noise.

:schwitz: This is where we still disagree I feel it's the reverse... If you don't want to buy my arguments that's one thing, but if I was wrong why would high performance vehicles not use recirc valves?:shrug:

Hell yes, looking nice is important. But I'd rather have functionality over looks any day, and I wouldn't sacrifice fuctionality or performance just for aesthetics. Hell, I drive an MX-5 - I know all about sacrificing image for ability :shy: But people who lower their car BECAUSE it looks nice, forgetting the pros and cons of the vast majority of bolt on lowering kits, rather than lowering it properly with all that entails for any performance benefits and then being pleased when it happens to look lower annoy me. Ricers don't walk into a shop and say I want to improve the suspension geometry on my car to enhance traction, despite the expense in handling (or whatever that particular component might do). They ask specifically to lower the car by 2 inches, paying little or no regard for what will happen when they do so.

This I totally agree with :D

[tristancliffe]

:schwitz: This is where we still disagree I feel it's the reverse... If you don't want to buy my arguments that's one thing, but if I was wrong why would high performance vehicles not use recirc valves?:shrug:


I guess it depends how high performance you mean. If you have lots of torque (even before the turbo's kick in) then you can run an open BOV because the high torque compensates for the slighly increased time to regain max pressure, and keeping the larger turbines spinning is the main priority. In a lower powered car (again depends on your definition of lower powered, but I'd say less than 300hp) I think the benefits of the recirc valve, for road driving, are greater.

But open or recirc, there's still no need to have a BOV that makes a silly noise. And it's a FACT that people fit BOV's for the noise and not the performance characteristics. Thats why there is an electronic box on sale that plays a recording of "pssssssssshhhhhhhhhhhhhhhhht" when you lift off if you don't even have a turbo. It's also the MAIN reason people ask about BOV's here. Not because it's simulated wrong (or not, I don't know), but because they want a louder noise. Which was, I think, how this topic started.

[cmckowen]

Yeah one of my friends had a blow off valve and swore by it...tried it for a minute and couldnt stand the sound... Was just too much!

[Ball Bearing Turbo]

I guess it depends how high performance you mean. If you have lots of torque (even before the turbo's kick in) then you can run an open BOV because the high torque compensates for the slighly increased time to regain max pressure, and keeping the larger turbines spinning is the main priority. In a lower powered car (again depends on your definition of lower powered, but I'd say less than 300hp) I think the benefits of the recirc valve, for road driving, are greater.

This is my main point, I feel that my arguments prove beyond reasonable doubt that recircs actually impede the turbo's inertia more than the atmospheric system, and therefore open BOVs would provide better response in any car... That's my point.... Unless you have the patience to disprove my reasonings from previous posts in some methodical fashion, then we'll probably just have to agree to disagree lol...

But open or recirc, there's still no need to have a BOV that makes a silly noise. And it's a FACT that people fit BOV's for the noise and not the performance characteristics. Thats why there is an electronic box on sale that plays a recording of "pssssssssshhhhhhhhhhhhhhhhht" when you lift off if you don't even have a turbo. It's also the MAIN reason people ask about BOV's here. Not because it's simulated wrong (or not, I don't know), but because they want a louder noise. Which was, I think, how this topic started.

Totally agreed.

Really you can purchase a fake BOV? ROFL

[Sil.Eighty.Style]

yeah, there's these whistle things you can mount in the exhaust to make it sound like a bov :x

im not too sure about the reasoning behind it, but i know for a fact that atmospheric bov's are more prone to stalling on deceleration (without proper tuning) than a recirc bov.

edit: sorry for bumping the old thread, didnt notice.

[Zion]

First of all, I admit that I have not read the whole thread.
Which means i dont really know what conclusion youve come to.

But on the first page, some guy (tristan??) made a point that the blowoff valve is unnescesery(spelling?), well that is for sure wrong.

Since i'm not very good at English and therefor have a bit of a problem explaining complex things in this language, I'll post a qoute to prove my point:

http://www.newton.dep.anl.gov/askasci/eng99/eng99202.htm

"
The blow-off valve should not be confused with a waste-gate. The waste-gate is a
device that by-passes the turbine wheel of the turbocharger, limiting the
shaft-speed of the turbocharger. Therefore, limiting the boost
(pressure) that the compressor generates and keeping the turbocharger
from over-speeding.

A blow-off valve is mounted in the intake plumbing between the
turbocharger compressor and the throttle plate. The blow-off valve is a
second safety measure against the turbocharger over-boosting and damaging
the engine.

The blow-off valve is more commonly used to keep the turbocharger spinning
when the throttle plate is suddenly closed. When the turbocharger is
generating maximum boost pressure at full throttle and then the throttle
is suddenly closed, compressed air coming from the compressor slams
against the throttle, generating extremely high pressures that travel
backwards to the compressor stopping the compressor from spinning. When
the throttle plate is again opened, the engine must spool the turbocharger
shaft again. The effects of this high pressure can also be very damaging
to the turbocharger.

Brian Wright
Washington University in St. Louis Formula SAE Racing

"

Well that kinda explains the use of a BOV, not saying you must have one, but that
it saves your equipment and reduces the turbolag(spool-up time) since the turbine keeps on spinning.

If you already come to this conclusion I'm sorry to repeat it.
If not, consider yourselfs enlighted! ;)

[Ball Bearing Turbo]

Indeed you are of course correct, however the debate is basically on which style of BOV is more efficient. Tristan feels that "reciculating" valves are more efficient while I feel that "atmospheric" valves are more efficient.

No matter that you didn't read the thread, I'm still right and Tristan is still wrong..... :razz:

:hide:

[tristancliffe]

I say the different types have 'efficiencies' which suit different applications (say road, fast road or race) best.

And BBT knows I'm right anyway, he's just being cheeky :D

[Greboth]

Ive spent the last 20 - 30 mins reading this whole thread but this is what i thought and correct me if im wrong.
I thought that a recirc did was better for day to day driving as it did decrease the time it takes for the turbo to spool but on high performance cars BOV were used as they need to dump pressure so a recirc would hinder the car. Also they use WOT more so the dumping isnt as critical.

I never got to look at my aunts car properly but im sure she had a BOV but it dumped into the exhuast system after the turbo so releasing pressure and not causing the psssssshh noise.
I cant be certain on that as it could of simply been a recirc.

Feel free to flame or correct me as i would like to know.
P.s. - ill try and ask my lecturer at uni :thumb: if someone would give me the question lol

[TheRealEddie]

heh, coming from a Rally background when I think wastegate, I think of a squirrel chirping :pillepall

[keltern]

Indeed you are of course correct, however the debate is basically on which style of BOV is more efficient. Tristan feels that "reciculating" valves are more efficient while I feel that "atmospheric" valves are more efficient.

No matter that you didn't read the thread, I'm still right and Tristan is still wrong..... :razz:

:hide:

i'd have to agree with you on the atmospheric type.. and tristan often talks about cars on the road, though in LFS, there are for ex. no streets (etc) to drive on.. :scratchch if there where, i'd still not agree with him! :razz:

everything is and could be rice, right tristan? :razz: :thumb:

[02arnoldj]

Can i Just say one thing. :D

Dump Valves / Blow off Valves may sound nice to Ricers in their Escort Rs Turbos, BUT what they don't (and a lot of other people Dont) Realise is that they reduce your engine life by up to 40,000 Miles :shy::nod:

Think about it, Pressure goes in and out and in and out and Nackers the engine Components eventually. Like i saw a Grey Fiat Punto with a Huge exaust that sounded like santa had a Vindaloo on Christmas eve and shat it out through a Trombone, and His Dump Valve sounded like Tony Blair Whispering to Osama Bin Laden in his cave! "PIIIISSSSSShhhhhhhhhT! WEKNOWYOURINTHEEEEEERE"

He obviously doesn't realise his shit piece Fiat Uno 1.4 aint gunna last much longer, Uno's have an engine life of about 60,000 miles, hes only got 20 left after his new Dump valve! Lol
NO OFFENCE TO ANYONE WITH AN UNO! !

[Ball Bearing Turbo]

Sadly that doesn't make any sense.

Specifically on vehicles with relatively high boost pressures, an atmospheric valve is necessary to alleviate the rapid obliteration of the bearing in the turbocharger (thrust). Going from lower to higher pressure and back again ad naseam does not lower the operating lifetime of an engine. As a matter of fact, any decent quality OEM mill will benefit from some boost, as it actully reduces the intensity of transient loads on the internal components (force is more evenly applied throughout the power stroke).

If you can supply some reasoned argument or at least semi-scientific basis for your argument, I'm all ears... Merely stating "high pressure -> low pressure = bad" is not much of an argument... However, the average ricer bolting some mismatched "stuff" onto his car is reason enough for a lower life expectancy, but not for the reasons you stated :)

[tristancliffe]

I know Uno's with over 250,000 miles on an engine. And not just one. Oil changes, the odd cambelt etc. Obviously it didn't do many short runs (the 2nd worst thing you can do to an engine) or get revved above 2000rpm with no load (the worst thing you can do). It was just cared for. But they were frequently driven like an Italian engine should be driven ;)

[keltern]

Can i Just say one thing. :D

Dump Valves / Blow off Valves may sound nice to Ricers in their Escort Rs Turbos, BUT what they don't (and a lot of other people Dont) Realise is that they reduce your engine life by up to 40,000 Miles :shy::nod:

Think about it, Pressure goes in and out and in and out and Nackers the engine Components eventually. Like i saw a Grey Fiat Punto with a Huge exaust that sounded like santa had a Vindaloo on Christmas eve and shat it out through a Trombone, and His Dump Valve sounded like Tony Blair Whispering to Osama Bin Laden in his cave! "PIIIISSSSSShhhhhhhhhT! WEKNOWYOURINTHEEEEEERE"

He obviously doesn't realise his shit piece Fiat Uno 1.4 aint gunna last much longer, Uno's have an engine life of about 60,000 miles, hes only got 20 left after his new Dump valve! Lol
NO OFFENCE TO ANYONE WITH AN UNO! !

can't see anyone agreeing with that..

blow off's are there to prevent the turbo from stalling or stopping (less stress on the engine components..) so how can you claim the oposite?

his car was probably doomed anyway, due to brutal driving and crappy components..

[wheel4hummer]

I want a duck call BOV!!!!!
http://www.youtube.com/watch?v=VbNxugO-uf0&mode=related&search

[02arnoldj]

I was told by a Fully Trained Mechanic who owns his own shop and knows absolutely everything there is to know, that A Blow Off Valve or Dump Valve (one or the other :S) Will reduce your engines life by UP to 40,000Miles, depending on how it's used.
This is the same with Mo-peds, if you De- Restrict them or get a "Metra Exaust kit" fitted, that takes UP to 20,000 miles off the engine life.


The Idea of a Turbo charger ,if i understand correctly, is that it Takes in Air, Forces it round (Highly Pressure) and then Forces it back in or out again when the Blow off Valve is opened??
If youre engine constantly has highly Compressed Air going through the Turbo all day every day then is it not Harmful to some Components?

[tristancliffe]

Your mechanic is an idiot, and knows absolutely nothing there is to know. I am a fully trained mechanic also (and my family owns our own engineering firm, of which I am a director-in-training), and I can tell you two things from that:

1. Fully Trained means you know how to use a spanner
2. It DOES NOT teach you about 'how stuff works'.

The thing about derestricting a moped (which is a completely different kettle aquarium) is that you are making the engine produce more work than the application (and thus the cooling, engine mounts etc) were designed for. On the other hand, the engine was designed originally to produce the unrestricted amount of power, and so would be fine.

Again, your mechanic is an idiot and a fool. Shun him.

[Ball Bearing Turbo]

I was told by a Fully Trained Mechanic who owns his own shop and knows absolutely everything there is to know, that A Blow Off Valve or Dump Valve (one or the other :S) Will reduce your engines life by UP to 40,000Miles, depending on how it's used.
This is the same with Mo-peds, if you De- Restrict them or get a "Metra Exaust kit" fitted, that takes UP to 20,000 miles off the engine life.


The Idea of a Turbo charger ,if i understand correctly, is that it Takes in Air, Forces it round (Highly Pressure) and then Forces it back in or out again when the Blow off Valve is opened??
If youre engine constantly has highly Compressed Air going through the Turbo all day every day then is it not Harmful to some Components?

Ask Mr. Knowsitall: "how would not releasing intake pressure affect a turbocharger when you slam the throttle shut" :really:

As far as the pressure generated by forced induction of any type: compare it to the cylinder pressures generated by expoding fuel air mixture.... It becomes a moot point quite rapidly doesn't it :smileypul

As illustrated in my previous post, most engines actually benefit in terms of longevity under reasonable boost conditions. This of course applies to sensical, properly designed turbocharging systems.