Recirculating Dump Valve

[price82]

does any one have one fitted to the r5 gt


also what effect would it have on my car currently has an induction kit so i guess the noise i get is wastegate chatter or turbo stall not too keen on it though rather it was silent???

thanks folks

[jure]

You will still have same turbo sound since you have "open" filter. I had Bosch recirc DV and it worked as any other DV except it was soundless.

[R5GTTRaider]

You won't get compresser surge but if you have it recirc to the front of the turbo it will make the turbo keep spinning better then a atmosphere vented dv, you may hear the dv but unlikley

[alister]

i find it hard to believe that the recirc dv feed to the inlet pipe of a 5 gt turbo will make any real difference

[R5GTTRaider]

i cant remeber for the life of me were i read it,
but basicly when a bov releases pressure it still slows down the turbo as the un equal pressures (ethier side of the compresser) makes the air want to go backwads though the turbo, but of course not as agressivly,

(i have heard slight air flutter at lower speeds/gear change were the psi isnt great and i can hear it over the dv)

so recirc to the inlet of the turbo
(for example in the pos of the oe breather pipe to telephone hose)
this would equalise the pressure both sides, keeping the turbo spining more than as above,

weather this does infact make a diffrence i couldnt comment, but it was a tech write up not forum banter

[Mart]

i find it hard to believe that the recirc dv feed to the inlet pipe of a 5 gt turbo will make any real difference

Correct, it won't. The exhaust gas pressure hitting the turbine will still be higher than any recirc'd air hitting the comp' wheel, plus you're also recirc'ing hot boost air back into a cold inlet - Hardly efficient when trying to keep the charge temp's low is it...

[R5GTTRaider]

Correct, it won't. The exhaust gas pressure hitting the turbine will still be higher than any recirc'd air hitting the comp' wheel, plus you're also recirc'ing hot boost air back into a cold inlet - Hardly efficient when trying to keep the charge temp's low is it...
how?

exhaust gases?
were talking dumpvalves,
and it wouldnt be majorly be hot, but still ive read it on wiki somewere and cant think were.
but were not talking charge temps, im saying it keeps the pressures eqaul.
but your talking the timyest amount of air,hardly going to effect temps?

[clee]

The CHARGE air will hottest coming out the turbo comp housing .....and you're adding heat to the inlet .

[R5GTTRaider]

no im talking about the cooled air after the i/c , the recirc dv will then route down before the compresser, not in the tube before the i/c,
i can see how it would work in thoery, but if it does then surely the equalisation of air and the pressure that hits the comp blades would keep it spinning

[RICHIE]

i can see were this thread is going:rolleyes:

[R5GTTRaider]

lol i aint going to argue, promise
BUT
if theres high pressure in the boost hoses, and low pressure before the compresser whell, whats low pressure (vacum) so thus it would try to draw air though
hold on im going to find a wiki article or something on this as i know im right this time..:p

[clee]

I know what to do !!!!

Fit one of these to the re circ ....:cooter:
http://www.demon-tweeks.co.uk/resources/images/zoom/DEI080110.jpg

[R5GTTRaider]

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

From Wikipedia, the free encyclopedia

Jump to: navigation (http://en.wikipedia.org/wiki/Dump_valve#column-one), search (http://en.wikipedia.org/wiki/Dump_valve#searchInput)
Dump valves are fitted to the engines of turbo charged (http://en.wikipedia.org/wiki/Turbocharger) cars and sit between the turbo outlet and the throttle body. When transitioning from a boosted state to a closed throttle state (as in between shifts), due to inertia (http://en.wikipedia.org/wiki/Inertia), the turbo continues to pressurize air, but the closed throttle prevents the compressed air from entering the engine. In this case the pressure exceeds the preset spring pressure in the dump valve and the excess pressure is bled off to atmosphere.
Even with a dump valve the compressed air acts as a brake on the turbo (slowing it down), because the pressure on the backside of the turbo is at a higher pressure than on the front side (and the air actually wants to flow through the turbo backwards).
A blowoff valve (http://en.wikipedia.org/wiki/Blowoff_valve) is a more elegant solution to this problem by allowing the turbo to "freewheel (http://en.wikipedia.org/wiki/Freewheel)" when the throttle is closed (equalizing the pressure on both sides of the turbo). Unlike a dump valve a blowoff valve can be used at multiple boost settings without reconfiguration.
Blowoff valves are sometimes incorrectly called dump valves because they serve a similar function, but they are very different solutions to the same problem.


:upyours: lol :laugh:

[Tiny Tim]

Errr

I'd like to know what Wiki sees the difference between a Dump Valve and a BOV are personally.

[clee]

You sticky to wiki ...I'll continue reading this thing.....It's called a book :scratch:

http://images.google.com/imgres?imgurl=http://ecx.images-amazon.com/images/I/51ARTNWR5CL._SL500_AA240_.jpg&imgrefurl=http://www.amazon.com/Induction-Performance-Practical-Supercharging-Turbocharging/dp/1859606911&usg=__ZVZEPtvfvwe5C8P_4NxYquGVgu4=&h=240&w=240&sz=18&hl=en&start=1&um=1&tbnid=Y8phSaPMKQiJRM:&tbnh=110&tbnw=110&prev=/images%3Fq%3Dforced%2Binduction%2Bperformance%2Btu ning%26hl%3Den%26rlz%3D1B2RNFA_enGB210GB210%26sa%3 DN%26um%3D1

[Tiny Tim]

You sticky to wiki ...I'll continue reading this thing.....It's called a book :scratch:

http://images.google.com/imgres?imgurl=http://ecx.images-amazon.com/images/I/51ARTNWR5CL._SL500_AA240_.jpg&imgrefurl=http://www.amazon.com/Induction-Performance-Practical-Supercharging-Turbocharging/dp/1859606911&usg=__ZVZEPtvfvwe5C8P_4NxYquGVgu4=&h=240&w=240&sz=18&hl=en&start=1&um=1&tbnid=Y8phSaPMKQiJRM:&tbnh=110&tbnw=110&prev=/images%3Fq%3Dforced%2Binduction%2Bperformance%2Btu ning%26hl%3Den%26rlz%3D1B2RNFA_enGB210GB210%26sa%3 DN%26um%3D1


:laugh: :agree:

[R5GTTRaider]

ok i have said before ill stand corrected, im just saying at the start, i was qestioned so i said, and wiki is what comes up, and i was under the impression they were proper technical articles, if not they must be wrong about every thing else from how turbos work to internal combustion

[R5GTTRaider]

You sticky to wiki ...I'll continue reading this thing.....It's called a book :scratch:

http://images.google.com/imgres?imgurl=http://ecx.images-amazon.com/images/I/51ARTNWR5CL._SL500_AA240_.jpg&imgrefurl=http://www.amazon.com/Induction-Performance-Practical-Supercharging-Turbocharging/dp/1859606911&usg=__ZVZEPtvfvwe5C8P_4NxYquGVgu4=&h=240&w=240&sz=18&hl=en&start=1&um=1&tbnid=Y8phSaPMKQiJRM:&tbnh=110&tbnw=110&prev=/images%3Fq%3Dforced%2Binduction%2Bperformance%2Btu ning%26hl%3Den%26rlz%3D1B2RNFA_enGB210GB210%26sa%3 DN%26um%3D1

i did have this book infact, so whats it say about recirc dv's and benifets?

[Tiny Tim]

Nothing wrong with Wiki most of the time, it's just that books are more likely to be written by experts, Wiki is more likely to be edited by Gaz, sitting on his mums laptop, stroking one off over the latest pictures of his XR2i on www.lowmeanstreetkroozers/geezers.com

[BriC]

if not they must be wrong about every thing else from how turbos work to internal combustion


Erm, No. Wiki articles are written by independant people, and hence, are not always correct. It has been known for Wikipedia to be incorrect on some matters.

[clee]

Link don't werk mate :cooter:

[BriC]

Nothing wrong with Wiki most of the time, it's just that books are more likely to be written by experts, Wiki is more likely to be edited by Gaz, sitting on his mums laptop, stroking one off over the latest pictures of his XR2i on www.lowmeanstreetkroozers/geezers.com (http://www.lowmeanstreetkroozers/geezers.com)

Link doesn't work? :scratch:

[Tiny Tim]

Behave. :rolleyes:

[BriC]

Link don't werk mate :cooter:

Why I oughta.. :mad:

[Misky]

ok i have said before ill stand corrected, im just saying at the start, i was qestioned so i said, and wiki is what comes up, and i was under the impression they were proper technical articles, if not they must be wrong about every thing else from how turbos work to internal combustion

Nope not wrong about everything, but its also not gospel truth!
As we know...Wiki can be edited by people with a distinct lack of knowledge! but so long as the article seems technical minded and well written the wiki team (who will have no knowledge on the subject) will allow this info to be posted until it is re-edited by a credited source/person.

[R5GTTRaider]

Erm, No. Wiki articles are written by independant people, and hence, are not always correct. It has been known for Wikipedia to be incorrect on some matters.
ok mate no problem, i know not to belive every thing you read but it seems plausable and works in thoery in my head or at least i can see how it would work to equalise the pressure, i understand that, but ok it could well be wrong...

[Tiny Tim]

So anyway... what IS the difference between a BOV and a D/V :rolleyes:

[clee]

i did have this book infact, so whats it say about recirc dv's and benifets?


It says ..

dey are the shizzle but DV's are better:devil: if you fit a horn to it the sonic wave gives another 10 bhp

[R5GTTRaider]

It says ..

dey are the shizzle but DV's are better:devil: if you fit a horn to it the sonic wave gives another 10 bhp
realy? wow better put 10 on there then :scared::wasntme::p


So anyway... what IS the difference between a BOV and a D/V :rolleyes:
pass.....
wiki here i come :wasntme:

[BriC]

it Says ..

Dey Are The Shizzle But Dv's Are Better:devil: If You Fit A Horn To It The Sonic Wave Gives Another 10 Bhp

Roflbrothel

[Duncan Grier]

Must dig the golf / vw mag that did a full test on a nissan pulsar thing with oe dv, forge, none etc etc and VERY interesting results! - Not what you would think :P

In theory recirc puts compressed air back into the inlet with a higher volume of air (a plus) but will also be warm / hot (not a plus lol)

Prefer recirc myself but once you mod your air intake you can still hear them :D but no where near like std dv

I prefered the cij wthout dv :P

[Tiny Tim]

Must dig the golf / vw mag that did a full test on a nissan pulsar thing with oe dv, forge, none etc etc and VERY interesting results! - Not what you would think :P


Please Dunc, that would be a good read.

I've got twin re-circs on mine. I know it's not ideal introducing warm(er) charge air back into the system but both mine come straight from the intercooler, so shouldnt be too devestating.

[clee]

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

[Tiny Tim]

:laugh::laugh:

[JRP]

You won't get compresser surge but if you have it recirc to the front of the turbo it will make the turbo keep spinning better then a atmosphere vented dv, you may hear the dv but unlikley


How many web sites do you want to fail on?

[R5GTTRaider]

Please Dunc, that would be a good read.

I've got twin re-circs on mine. I know it's not ideal introducing warm(er) charge air back into the system but both mine come straight from the intercooler, so shouldnt be too devestating.
and with only a little amount of air (compared to the amount of cold air entering the front side, do you see higher charge temps?

[Tiny Tim]

and with only a little amount of air (compared to the amount of cold air entering the front side, do you see higher charge temps?


Than what? - This is an OE set-up bruv.

[R5GTTRaider]

How many web sites do you want to fail on?
ah shut up lol. you my man have a big wooden spoon :p

na i will carry on saying ill stand corrected and wont say nope thats that and no one else is right..

any how whats happening tomorrow?u still going to fidos or you working on yours?

[R5GTTRaider]

Than what? - This is an OE set-up bruv.
is it... i didnt know bud :ashamed:

[BriC]

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

OMFG, did you put that on the end? :cry::laugh:

[D4WNO]

I think what people are trying to say is that Google/Wiki etc aren't always right and you shouldn't trust them. Did you know that Wiki is a public website, and anybody can contribute any old crap to it? (without the lsightest bit of knowledge, might I add)

It's just very dangerous posting things that you're not sure of, even anything you're only 99% sure on is not helpful. If someone follows your advice and it blows up in their face as they don't know any better either, then you're not going to like the outcome.

Please only post things you are certain on, half-knowledgable or poor internet-gained advice are just not useful to anyone...plus you're making yourself look silly.

We have lots of very knowledgable members in certain areas, so if you don't post a reply we need not worry that the Op won't get the answers that they need. We pretty much have all bases covered, so don't feel the need to contribute to everything ever written. I mean this in the kindest way, just be careful what you write.

Back on topic now please :D

[R5GTTRaider]

OMFG, did you put that on the end? :cry::laugh:
do what :scratch:


I think what people are trying to say is that Google/Wiki etc aren't always right and you shouldn't trust them. Did you know that Wiki is a public website, and anybody can contribute any old crap to it? (without the lsightest bit of knowledge, might I add)

It's just very dangerous posting things that you're not sure of, even anything you're only 99% sure on is not helpful. If someone follows your advice and it blows up in their face as they don't know any better either, then you're not going to like the outcome.

Please only post things you are certain on, half-knowledgable or poor internet-gained advice are just not useful to anyone...plus you're making yourself look silly.

We have lots of very knowledgable members in certain areas, so if you don't post a reply we need not worry that the Op won't get the answers that they need. We pretty much have all bases covered, so don't feel the need to contribute to everything ever written. I mean this in the kindest way, just be careful what you write.

Back on topic now please :D
i wasnt giving advice,i was discusing that fact and again ill say i dont belive all i read
but it seems logical it works, and that ill stand corrected

and any how how can this


Must dig the golf / vw mag that did a full test on a nissan pulsar thing with oe dv, forge, none etc etc and VERY interesting results! - Not what you would think :P

In theory recirc puts compressed air back into the inlet with a higher volume of air (a plus) but will also be warm / hot (not a plus lol)

Prefer recirc myself but once you mod your air intake you can still hear them :D but no where near like std dv

I prefered the cij wthout dv :P

be not challaged and what i say does, and were both on the same level with this ??

simple qestion mind..

[BriC]

do what :scratch:

Pretty sure I was quoting Clee, and hence was directing the question to him.

Dawno - look at the end of that Dump Valve page, I think Clee added something onto the end of it which just proves the point both you and I were making!

[R5GTTRaider]

oh i relise that, but i dunno, im not going to carry on as its pointless as i cant explain what im thinking/trying to say properly

[Mart]

how?

exhaust gases?
were talking dumpvalves,
and it wouldnt be majorly be hot, but still ive read it on wiki somewere and cant think were.
but were not talking charge temps, im saying it keeps the pressures eqaul.
but your talking the timyest amount of air,hardly going to effect temps?

I know we're talking about dumpvalves, thanks, but if you read my post I was explaining how the (higher) exhaust gas pressure would still spin the turbo as such more so than recirculating boost air back onto the compressor's inducer to achieve that, so no, it won't keep the pressures equal (whatever that's supposed to mean anyway?). If you honestly believe a recirc' will maintain turbo spool/rpm/boost when you're changing gear, then you're misinformed.

Recirc's are fitted simply for noise & emission control. Period. No everyday car manufacturer is going to produce a car that hisses & sneezes at every gear change/backing off the throttle, as, on the whole, 'normal' folk don't want their cars sounding like a rally car or whatever, nor are they gonna allow any emissions to 'escape' to atmosphere that way as the Greenpeace hippies would have a field day if that was the case.

And yes, we are also talking charge temp's at the end of the day, as whatever way you cut it you're recirc'ing hot boost air back into the inlet (no intercooler is 100% efficient. Fact), and if you know anything about tuning you'll know that a cold(er) air intake temp' is king.

[BriC]

Mart FTW :D

(I bet he still comes back with his 'no but..' comments)

[R5GTTRaider]

I know we're talking about dumpvalves, thanks, but if you read my post I was explaining how the (higher) exhaust gas pressure would still spin the turbo as such more so than recirculating boost air back onto the compressor's inducer to achieve that, so no, it won't keep the pressures equal (whatever that's supposed to mean anyway?). If you honestly believe a recirc' will maintain turbo spool/rpm/boost when you're changing gear, then you're misinformed.

Recirc's are fitted simply for noise & emission control. Period. No everyday car manufacturer is going to produce a car that hisses & sneezes at every gear change/backing off the throttle, as, on the whole, 'normal' folk don't want their cars sounding like a rally car or whatever, nor are they gonna allow any emissions to 'escape' to atmosphere that way as the Greenpeace hippies would have a field day if that was the case.

And yes, we are also talking charge temp's at the end of the day, as whatever way you cut it you're recirc'ing hot boost air back into the inlet (no intercooler is 100% efficient. Fact), and if you know anything about tuning you'll know that a cold(er) air intake temp' is king.
no but... joking

i do agree i was merly discusing the subject, and purly getting a better knowlage of them, which is why it doesnt bother me when people take the pee, as i know im only asking and not like "i know all,listen to me and nothing else goes" as thats not how i want,or mean to come across

[Mart]

Nowt wrong with a good tech' discussion, it's a shame there isn't more on here, but don't believe everything you read on Wiki/Google searches as there's plenty of 'keyboard tuners' out there for sure.

[R5GTTRaider]

Nowt wrong with a good tech' discussion, it's a shame there isn't more on here, but don't believe everything you read on Wiki/Google searches as there's plenty of 'keyboard tuners' out there for sure.
again i agree, i know wiki is something that can be changed.

i do need to get a good turbo book,whats that book about forced induction like, i had it years ago, even if its the same one, remebr first lerning about turbos in a maxpower (iirc) guide to turbos etc think i still got it!! that was years ago lol

[Duncan Grier]

I know we're talking about dumpvalves, thanks, but if you read my post I was explaining how the (higher) exhaust gas pressure would still spin the turbo as such more so than recirculating boost air back onto the compressor's inducer to achieve that, so no, it won't keep the pressures equal (whatever that's supposed to mean anyway?). If you honestly believe a recirc' will maintain turbo spool/rpm/boost when you're changing gear, then you're misinformed.

Recirc's are fitted simply for noise & emission control. Period. No everyday car manufacturer is going to produce a car that hisses & sneezes at every gear change/backing off the throttle, as, on the whole, 'normal' folk don't want their cars sounding like a rally car or whatever, nor are they gonna allow any emissions to 'escape' to atmosphere that way as the Greenpeace hippies would have a field day if that was the case.

And yes, we are also talking charge temp's at the end of the day, as whatever way you cut it you're recirc'ing hot boost air back into the inlet (no intercooler is 100% efficient. Fact), and if you know anything about tuning you'll know that a cold(er) air intake temp' is king.

Mart, the test results on the Nissan from memory were very interesting around this as the uprated recirc was better than atmosphere for 1 part of the test but not the other (sure it was speed through the gears) controlled speed tests. No dv at all was quicker than some options but not advised for the reasons we already know. On some new engines that control boost via solinoids etc donot like atmos dv and can cause all sorts of issues. Also the recir was slower on the nissan than none but the new 2.0t (vag) was quicker with the forge recirc

Guess it is not 1 rule for all cars - std or modded :)

[clee]

again i agree, i know wiki is something that can be changed.

i do need to get a good turbo book,whats that book about forced induction like, i had it years ago, even if its the same one, remebr first lerning about turbos in a maxpower (iirc) guide to turbos etc think i still got it!! that was years ago lol

It does get very technical in a lot of places but also has lots of good DIY advice and if you read it a few times it will sink in .
End of the day you need to read it with an eye on what you want to achieve and most importantly the car you're applying it to .
Take absolutely no notice of anything I say regarding inter coolers etc as I'm special needs ..............

[rs250nut]

For fcuks sake not another dump valve thread. Search function is your friend:)

[Mart]

Mart, the test results on the Nissan from memory were very interesting around this as the uprated recirc was better than atmosphere for 1 part of the test but not the other (sure it was speed through the gears) controlled speed tests. No dv at all was quicker than some options but not advised for the reasons we already know. On some new engines that control boost via solinoids etc donot like atmos dv and can cause all sorts of issues. Also the recir was slower on the nissan than none but the new 2.0t (vag) was quicker with the forge recirc

Guess it is not 1 rule for all cars - std or modded :)

It was probably better (I assume you mean from turbo spool point of view) due to the recirc' valve maintaining some form of pressure within the boost cct, hence the turbo didn't have to re-produce/spool as much boost when back on the throttle. Now compare that to a vta dump valve, where it effectively 'empties' the boost circuit of air, hence more (read longer) spool-up to produce full boost again.

As for the 'reasons we already know' for not running a d.v; if you mean by that, that it shortens turbo life by not having one in situ, I don't subscribe to that whatsoever.

The fact you mention a Forge Motorsport product having a hand in the comparison stakes probably means it was a flawed test from the start anyway...

[R5GTTRaider]

The fact you mention a Forge Motorsport product having a hand in the comparison stakes probably means it was a flawed test from the start anyway...
most defently, any company will make there product look ten times better then there rival

like tesco and asda for example each advert saying they got tons more cheaper items, well hang on whos right?? lol neiter there both the same price across the board,

any how on topic they would "sabotage" the comparative item to make theres look best

bit like the ebay turbos, coz i want 3 of them and some chips too:laugh: