can you get a dumn valve on a turbo diesel??? just wondering.. it would be funny... turbs
General A dumb valve?? on jtd
- Thread starter leon_in_uk
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General A dumb valve?? on jtd
Please dont. You do not need one on a JTD as you don't have the back pressure and it will proabably loose you power. Only people with s**t cars and 90's XR3i's (Imprezza's to you) want them.... (I know they are the same thing but its worth explaining)
Alfa Romeo 156 2.4 JTD (210BHP)
Fiat Punto JTD (130BHP)
Fiat Barchetta
http://www.angeltuning.co.uk
http://www.bravo-guide.co.uk THE Fiat Bravo site
Alfa Romeo 156 2.4 JTD (210BHP)
Fiat Punto JTD (130BHP)
Fiat Barchetta
http://www.angeltuning.co.uk
http://www.bravo-guide.co.uk THE Fiat Bravo site
smokeme
Established member
To answer the question, yes you can but you don´t need it. It wouldn´t loose power because it has a preset pressure to release at (usually set by owner). If you increase the boost on your turbo you might need it but not in it´s stock form
OP
OP
yes but it will sound better wont it?? also faster in the gear change???
James M
Established member
Dumb valve, thats quite funny
As for sound, its one of those things you need to remeber you need to live with it, a bit like a daft exhaust its something which could mean ultimate embarrassment in some situations.
Stilo TURBO!!!!(diesel)
As for sound, its one of those things you need to remeber you need to live with it, a bit like a daft exhaust its something which could mean ultimate embarrassment in some situations.
Stilo TURBO!!!!(diesel)
Mick C
New member
Hi All
'scuse me but here's a dumbass question for you -
what does a dump valve do? are there any benefits with certain turbo engines? Is it just a "look at me" noise thing?
Thanks in advance for the education.....
Stilo MY04 1.6 Active Sport
Met. Black
'scuse me but here's a dumbass question for you -
what does a dump valve do? are there any benefits with certain turbo engines? Is it just a "look at me" noise thing?
Thanks in advance for the education.....
Stilo MY04 1.6 Active Sport
Met. Black
smokeme
Established member
The Great Blow Off Valve Debate:
First of all to understand the functionality and benefits of a blow off valve you have to have a complete understanding of how a turbocharger works. If you don't understand the basic mechanics of a turbocharger you can forget about trying to understand the benefits of a blow off valve. If you do understand the mechanics of a turbocharger, read on...
An Explanation of Compressor Surge:
The turbine in a turbocharger in its ideal mode is spinning at a very high rate and therefore generating lots of pressurized air that is fed into the OPEN (wide open throttle) intake manifold which translates into more power, but what happens when you take your foot off the gas when shifting between gears? The turbine in the turbo is still spinning at a high rate but now you've taken your foot off the gas and the intake manifold is CLOSED. Now the turbine spinning at a high rate and is trying to push out all this compressed air but since the manifold is closed, that compressed air has nowhere to go. What happens next is that the turbine slows down because of this pressure build-up between the compressor and the intake manifold. Since the pressurized air can't go forward into the engine it heads the wrong way back towards the turbo where it slows the turbine down (compressor surge). After you shift gears and you step on the gas again you want to have the turbine spinning fast so that its producing boost but since you took your foot off the gas and caused compressor surge, it slowed down, so you have to wait for the turbine to "spool up" (spin fast) again. This delay waiting for turbines to spool up is what causes some of the performance degradation that were trying to avoid.
The Blow off Valve:
What if we could figure out a way of eliminating compressor surge? Then the turbine in our turbo would have a much easier time keeping its speed up and we wouldn't get the lag in power waiting for the turbine to spool up between shifts. Enter the Blow off valve. At that moment in time between shifts when compressor surge is slowing the turbine down we'll just poke a hole in the tube running between the turbo and the intake manifold and let all that air leak out somewhere. The turbine can keep spinning fast & we'll have lots of boost when we step on the gas again. We'll also want to plug up that hole we made because we have a purpose for that pressurized air now, where as when we let off the gas we did not. The blow off valve is a gizmo that's constantly opening and closing giving you that cool sneeze sound when it "pokes" that hole in the intake manifold tube to keep the turbine spinning fast. We've eliminated compressor surge but we did confuse the engine just a bit since the ECU already told the injectors to issue fuel to be used for the air that we've now thrown out. Other than that sounds like a good idea right? so what if were running a bit rich for a moment, no big deal. Before you place your order read on...
The Re-circulating Valve... a better idea:
How about instead of poking a hole in the turbo to intake manifold tube and just letting the air leak out wherever it wants to, we could direct that pressurized air somewhere else where we could hold on to it until we need it again? The intake side of the compressor housing (between the intercooler and the turbo) would be a good place wouldn't it? that way we wouldn't slow the turbine down and we would have that pressurized air that would have otherwise been thrown out, ready in a really good place when we need it. On top of that we´ve got still got the correct air/fuel ratio going since we're not throwing and air out, just moving it from one place to another within the intake system. Instead of having to suck in air for the turbo to pressurize, we've got some pressurized air with the correct fuel amount already waiting. Now we've got all the benefits of a blow off valve and then some. That's a re-circulating valve.
Courtesy of zxttsteve(a friend)
If you read this far i really hope you learned something. Glad to be of help
First of all to understand the functionality and benefits of a blow off valve you have to have a complete understanding of how a turbocharger works. If you don't understand the basic mechanics of a turbocharger you can forget about trying to understand the benefits of a blow off valve. If you do understand the mechanics of a turbocharger, read on...
An Explanation of Compressor Surge:
The turbine in a turbocharger in its ideal mode is spinning at a very high rate and therefore generating lots of pressurized air that is fed into the OPEN (wide open throttle) intake manifold which translates into more power, but what happens when you take your foot off the gas when shifting between gears? The turbine in the turbo is still spinning at a high rate but now you've taken your foot off the gas and the intake manifold is CLOSED. Now the turbine spinning at a high rate and is trying to push out all this compressed air but since the manifold is closed, that compressed air has nowhere to go. What happens next is that the turbine slows down because of this pressure build-up between the compressor and the intake manifold. Since the pressurized air can't go forward into the engine it heads the wrong way back towards the turbo where it slows the turbine down (compressor surge). After you shift gears and you step on the gas again you want to have the turbine spinning fast so that its producing boost but since you took your foot off the gas and caused compressor surge, it slowed down, so you have to wait for the turbine to "spool up" (spin fast) again. This delay waiting for turbines to spool up is what causes some of the performance degradation that were trying to avoid.
The Blow off Valve:
What if we could figure out a way of eliminating compressor surge? Then the turbine in our turbo would have a much easier time keeping its speed up and we wouldn't get the lag in power waiting for the turbine to spool up between shifts. Enter the Blow off valve. At that moment in time between shifts when compressor surge is slowing the turbine down we'll just poke a hole in the tube running between the turbo and the intake manifold and let all that air leak out somewhere. The turbine can keep spinning fast & we'll have lots of boost when we step on the gas again. We'll also want to plug up that hole we made because we have a purpose for that pressurized air now, where as when we let off the gas we did not. The blow off valve is a gizmo that's constantly opening and closing giving you that cool sneeze sound when it "pokes" that hole in the intake manifold tube to keep the turbine spinning fast. We've eliminated compressor surge but we did confuse the engine just a bit since the ECU already told the injectors to issue fuel to be used for the air that we've now thrown out. Other than that sounds like a good idea right? so what if were running a bit rich for a moment, no big deal. Before you place your order read on...
The Re-circulating Valve... a better idea:
How about instead of poking a hole in the turbo to intake manifold tube and just letting the air leak out wherever it wants to, we could direct that pressurized air somewhere else where we could hold on to it until we need it again? The intake side of the compressor housing (between the intercooler and the turbo) would be a good place wouldn't it? that way we wouldn't slow the turbine down and we would have that pressurized air that would have otherwise been thrown out, ready in a really good place when we need it. On top of that we´ve got still got the correct air/fuel ratio going since we're not throwing and air out, just moving it from one place to another within the intake system. Instead of having to suck in air for the turbo to pressurize, we've got some pressurized air with the correct fuel amount already waiting. Now we've got all the benefits of a blow off valve and then some. That's a re-circulating valve.
Courtesy of zxttsteve(a friend
)If you read this far i really hope you learned something. Glad to be of help
smokeme
Established member
hehehe guess you have your answer then
OP
OP
yes cheers for the time to do that? so do you think its a benefit or not? will it cool down better when you rag your engine and turn it off straight away, (not that i do).. but cheers
Mick C
New member
Smokeme thanks! Enlightenment has taken place [8)]
So... at the end of the day, what do we think? waste of time on a JTD? (performance wise) or strictly for those wanting to draw attention to themselves?
Stilo MY04 1.6 Active Sport
Met. Black
So... at the end of the day, what do we think? waste of time on a JTD? (performance wise) or strictly for those wanting to draw attention to themselves?
Stilo MY04 1.6 Active Sport
Met. Black
OP
OP
^^^^^ would do you think smokeme???? good comment mick.
smokeme
Established member
Do you need it?
Not really, unless you increased boost, installed intake and exhaust(you shouldn´t change just one, why more air in if it can´t get out and vice versa) then you should look at getting one fitted.
Does it draw attention?
Once again not really, unless you have high boost it will barely be heard.
Cool engine better?
No not at all. That´s the purpose of a turbo timer which let´s the car idle for a few minutes after you turn it off and remove the key.
(you won´t be able to drive the car with the timer on as it will stall if revved so no stealing)
Not really, unless you increased boost, installed intake and exhaust(you shouldn´t change just one, why more air in if it can´t get out and vice versa
) then you should look at getting one fitted.Does it draw attention?
Once again not really, unless you have high boost it will barely be heard.
Cool engine better?
No not at all. That´s the purpose of a turbo timer which let´s the car idle for a few minutes after you turn it off and remove the key.
(you won´t be able to drive the car with the timer on as it will stall if revved
so no stealing)
It will actually slow a Diesel down! It'll reduce the air going into the engine when it sneezes, so reducing the air going out the zorst, slowing down the turbo.
You don't really need one on Diesels anyway as there's no throttle butterfly to close, so the air from the turbo doesn't meet a dead end and need venting. More for show than anything else in this case.
BTW, my Cinq runs 0.3 bar and sneezes quite bloody loud!
Pete.
Links: 1242cc cinq, turbo cinq, Cinqs&Seis Yahoo group, Clubcento
You don't really need one on Diesels anyway as there's no throttle butterfly to close, so the air from the turbo doesn't meet a dead end and need venting. More for show than anything else in this case.
BTW, my Cinq runs 0.3 bar and sneezes quite bloody loud!
Pete.
Links: 1242cc cinq, turbo cinq, Cinqs&Seis Yahoo group, Clubcento
smokeme
Established member
You´re probably using a small low lag turbo, or a small BOV which causes a louder noise. Mine are homemade and actually shriek with a very high pitched sound it hurts your ears if the windows are down. Some diesels do come with bovs from the factory some Mack trucks, Golf gtd, most Cat engines(low rpm, high torque versions)
If you have any questions don´t be afraid, ask away. I´ll be glad to help.
. Some diesels do come with bovs from the factory some Mack trucks, Golf gtd, most Cat engines(low rpm, high torque versions)If you have any questions don´t be afraid, ask away. I´ll be glad to help.
OP
OP
so will it slow then smokeme? and will it ware or disturb my engine life? cheers matey
smokeme
Established member
No it won´t slow down your turbo and it won´t have any effect on engine life.
fixitagaintomorrow
A BOV is a pressure release valve it won´t sneeze UNLESS the pressure in the intake surpasses the BOVs preset pressure, so it will not slow down your turbo. A incorrectly set BOV will actually sneeze all the time or not at all.
If you have any questions don´t be afraid, ask away. I´ll be glad to help.
fixitagaintomorrow
A BOV is a pressure release valve it won´t sneeze UNLESS the pressure in the intake surpasses the BOVs preset pressure, so it will not slow down your turbo. A incorrectly set BOV will actually sneeze all the time or not at all
.If you have any questions don´t be afraid, ask away. I´ll be glad to help.
OP
OP
ok then so i think i might get 1 then? how much do you think i should spend? also could i fit it myself or do i have to pay s**te loads to get it fixed???
Originally posted by smokeme
No it won´t slow down your turbo and it won´t have any effect on engine life.
fixitagaintomorrow
A BOV is a pressure release valve it won´t sneeze UNLESS the pressure in the intake surpasses the BOVs preset pressure, so it will not slow down your turbo. A incorrectly set BOV will actually sneeze all the time or not at all
If you have any questions don´t be afraid, ask away. I´ll be glad to help.
Right, we're at cross purposes here.
A dump valve on a petrol turbo engine does not regulate the boost pressure, that's the job of the wastegate. The dump valve is vacuum operated and releases any pressure in the intake when the throttle is closed and the manifold vacuum rises.
On a Diesel you have no throttle to close, the intake is wide open all the time and power is regulated by fuelling.
If the turbo is allowed to belt all its air into the intake and not vent it, all this extra air will go through the engine and spin the turbo. Venting through a dump valve will reduce the amount of air going into and out of the engine, so the turbo will have less exhaust gas to spin it. A dump valve will increase turbo lag on a turbo diesel.
Not taking the mick, but how would a dump valve be operated on a Diesel as there's no intake vacuum to operate it - is it electronic?
Pete.
Links: 1242cc cinq, turbo cinq, Cinqs&Seis Yahoo group, Clubcento
smokeme
Established member
There are electronic ones but i found them to be a waste of money. I still think it can be placed on a diesel. here´s pics:
http://www.turbostylez.de/picx/bov/hdi/hdi_bov_06.jpg
BTW how can the same amount of air go through a diesel when you take your foot of the accelerator[}] i´ve always learned about fuel/air ratio, how´s that achieved on a diesel?
Maybe this might shed a bit of light.
http://www.turbodieselregister.com/forums/archive/topic/61366.html
Like i said, increased boost you´ll need a bov
_____________________________________________________________
If you have any questions don´t be afraid, ask away. I´ll be glad to help.
http://www.turbostylez.de/picx/bov/hdi/hdi_bov_06.jpg
BTW how can the same amount of air go through a diesel when you take your foot of the accelerator[}
] i´ve always learned about fuel/air ratio, how´s that achieved on a diesel?Maybe this might shed a bit of light
.http://www.turbodieselregister.com/forums/archive/topic/61366.html
Like i said, increased boost you´ll need a bov
_____________________________________________________________
If you have any questions don´t be afraid, ask away. I´ll be glad to help.
