Dump Valve

tri_longer · 31-05-2006, 19:06

Hi All

For those of you with more techincal knowledge than me I could do with someone explaining something for me.

If you fit a dump valve the opposite way round to the standard way, why does it still work, and if you do so does it have an detrimental effect on the flow of air?

I'm sure there is a simple explanation.

Lummox · 31-05-2006, 20:08

Its basically a valve. All it does it open and shut so it doesnt really matter which way around it goes, it still opens one side to the other.

Nigel26 · 01-06-2006, 11:01

i read a document on the recirc valves used on 1.8T VAG engines once. Cant remember where or who wrote it now but they also agreed that some valves actually worked better when installed "the wrong way".

Apparently the Bailey valve i have and the Forge that is common on here (007?) works best when installed the right way up.

Some people have said that the valves are louder when installed incorrectly. it all depends what your after i suppose.

tri_longer · 01-06-2006, 11:33

I've got the DV006, which doesn't seem to make much noise when installed correctly but can be clearly heard (though not to over the top) when installed the wrong way round.

What i'm struggling with (bear with me I can be a bit slow on the uptake) is the physics of the air flow and the piston.

Installed correctly air pushes against the sprung piston to open valve, however, if installed the other way round the air is pushing against the top of the piston, therefore keeping it closed.

Very confused, it clearly works, i just don't undersatnd why. Either that or i have completely misunderstood the flow though the DV.

elegance1.8T · 01-06-2006, 11:40

I don't know about the physics part but mine felt exactly the same both ways around and sounded the same as well, as you heard the other day. I spoke to yellowcupra the other day and he can do my car, woohooo here we go!
hope you are ok

tri_longer · 01-06-2006, 11:49

Quote:

Originally Posted by elegance1.8T

I don't know about the physics part but mine felt exactly the same both ways around and sounded the same as well, as you heard the other day. I spoke to yellowcupra the other day and he can do my car, woohooo here we go!
hope you are ok

Yours sounds really nice, just enough without being chavvy. I tried mine reversed and it worked fine and sounded like yours.

The only reason I have put it back to normal is I am worried about any detrimental effect, mainly because I just can't get my head around how the DV works.

On the tuning side, excellent news, when have you booked it in for?

elegance1.8T · 01-06-2006, 12:40

He is coming to do it on sunday afternoon, not getting my wheel bearing done until tuesday so will have to resist temptation, will be very difficult.
He has got it properly sorted as he is getting rid of the silly revo trial first so there will be no chance of it messing up again!
wish me luck.
You'll have to come and have a play in it when it's all working properly!

tri_longer · 01-06-2006, 14:24

look forward to it

Nigel26 · 01-06-2006, 16:32

AFAIK your right in that the boost pressure pushes the valve open then is closes dumping the excess boost back into the airbox / intake system.

I couldnt understand how the valve would work when installed the wrong way round either so just put mine in the right way up.

roblatus · 01-06-2006, 18:14

Quote:

Originally Posted by elegance1.8T

He is coming to do it on sunday afternoon, not getting my wheel bearing done until tuesday so will have to resist temptation, will be very difficult.
He has got it properly sorted as he is getting rid of the silly revo trial first so there will be no chance of it messing up again!
wish me luck.
You'll have to come and have a play in it when it's all working properly!

It will be impossible for you to resist temptation once you have the re-map done

Trust me on this

Glad you got it sorted so that you can get it done though. Let us know what it is like

elegance1.8T · 01-06-2006, 18:20

Remap, I don't know what you are talking about

I will resist, I don't want a 3 wheeler with a touch over the 150 std bhp!!!!

elegance1.8T · 01-06-2006, 18:23

BTW Rob, what sort of output has your car got, bhp and torque wise, PM me with it if you don't want public knowledge.

roblatus · 02-06-2006, 08:21

Quote:

Originally Posted by elegance1.8T

BTW Rob, what sort of output has your car got, bhp and torque wise, PM me with it if you don't want public knowledge.

I had the generic Jabba re-map. They quoted me figures of 206-215 Bhp and 220-230 lb/ft of torque.

I would like to kow how accurate these figures are as mine has never been rolling roaded.

31-05-2006, 19:06	#1
tri_longer Briskodian Join Date: Feb 2006 Location: Bradford Posts: 132 Thanks: 0 Thanked 0 Times in 0 Posts	Dump Valve Hi All For those of you with more techincal knowledge than me I could do with someone explaining something for me. If you fit a dump valve the opposite way round to the standard way, why does it still work, and if you do so does it have an detrimental effect on the flow of air? I'm sure there is a simple explanation.

31-05-2006, 20:08	#2
Lummox U18 Automotive Join Date: Sep 2003 Location: Newport Pagnell Posts: 21,750 Thanks: 22 Thanked 634 Times in 544 Posts	Re: Dump Valve Its basically a valve. All it does it open and shut so it doesnt really matter which way around it goes, it still opens one side to the other. __________________ Unit 18 Automotive Services now open Servicing, repairs, modifications you name it we do it. Cupra console bushes at special price, PM for a very competitive quote.

01-06-2006, 11:01	#3
Nigel26 Briskodian Join Date: Nov 2003 Location: Walsall, West Midlands Posts: 2,298 Thanks: 0 Thanked 0 Times in 0 Posts	Re: Dump Valve i read a document on the recirc valves used on 1.8T VAG engines once. Cant remember where or who wrote it now but they also agreed that some valves actually worked better when installed "the wrong way". Apparently the Bailey valve i have and the Forge that is common on here (007?) works best when installed the right way up. Some people have said that the valves are louder when installed incorrectly. it all depends what your after i suppose. __________________ Sea Grey Mondeo Titanium X

01-06-2006, 11:33	#4
tri_longer Briskodian Join Date: Feb 2006 Location: Bradford Posts: 132 Thanks: 0 Thanked 0 Times in 0 Posts	Re: Dump Valve I've got the DV006, which doesn't seem to make much noise when installed correctly but can be clearly heard (though not to over the top) when installed the wrong way round. What i'm struggling with (bear with me I can be a bit slow on the uptake) is the physics of the air flow and the piston. Installed correctly air pushes against the sprung piston to open valve, however, if installed the other way round the air is pushing against the top of the piston, therefore keeping it closed. Very confused, it clearly works, i just don't undersatnd why. Either that or i have completely misunderstood the flow though the DV.

01-06-2006, 11:40	#5
elegance1.8T Briskodian Join Date: Jun 2003 Location: Bury, Lancs Posts: 866 Thanks: 8 Thanked 13 Times in 2 Posts	Re: Dump Valve I don't know about the physics part but mine felt exactly the same both ways around and sounded the same as well, as you heard the other day. I spoke to yellowcupra the other day and he can do my car, woohooo here we go! hope you are ok __________________ No longer a Skoda owner But got a new BMW coming in 2 weeks, thats going to make me a really bad driver!

01-06-2006, 12:40	#7
elegance1.8T Briskodian Join Date: Jun 2003 Location: Bury, Lancs Posts: 866 Thanks: 8 Thanked 13 Times in 2 Posts	Re: Dump Valve He is coming to do it on sunday afternoon, not getting my wheel bearing done until tuesday so will have to resist temptation, will be very difficult. He has got it properly sorted as he is getting rid of the silly revo trial first so there will be no chance of it messing up again! wish me luck. You'll have to come and have a play in it when it's all working properly! __________________ No longer a Skoda owner But got a new BMW coming in 2 weeks, thats going to make me a really bad driver!

01-06-2006, 14:24	#8
tri_longer Briskodian Join Date: Feb 2006 Location: Bradford Posts: 132 Thanks: 0 Thanked 0 Times in 0 Posts	Re: Dump Valve look forward to it

01-06-2006, 16:32	#9
Nigel26 Briskodian Join Date: Nov 2003 Location: Walsall, West Midlands Posts: 2,298 Thanks: 0 Thanked 0 Times in 0 Posts	Re: Dump Valve AFAIK your right in that the boost pressure pushes the valve open then is closes dumping the excess boost back into the airbox / intake system. I couldnt understand how the valve would work when installed the wrong way round either so just put mine in the right way up. __________________ Sea Grey Mondeo Titanium X

01-06-2006, 18:20	#11
elegance1.8T Briskodian Join Date: Jun 2003 Location: Bury, Lancs Posts: 866 Thanks: 8 Thanked 13 Times in 2 Posts	Re: Dump Valve Remap, I don't know what you are talking about I will resist, I don't want a 3 wheeler with a touch over the 150 std bhp!!!! __________________ No longer a Skoda owner But got a new BMW coming in 2 weeks, thats going to make me a really bad driver!

01-06-2006, 18:23	#12
elegance1.8T Briskodian Join Date: Jun 2003 Location: Bury, Lancs Posts: 866 Thanks: 8 Thanked 13 Times in 2 Posts	Re: Dump Valve BTW Rob, what sort of output has your car got, bhp and torque wise, PM me with it if you don't want public knowledge. __________________ No longer a Skoda owner But got a new BMW coming in 2 weeks, thats going to make me a really bad driver!

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