Interesting Dump Valve Information For New Buyers And Owners. Servicing Etc

[badger5]

How much cash do you want to bet that I haven't lapped it in I just took the O rings out and used a pole from an old toy bow and arrow (I bought it for a fancy dress night out!) as a sucker on the piston and some valve paste I have had in my toolbox for years. Seemed to work well haha.

My test was the same as Niki posted on facebook a while back, but I couldn't find a way to seal off the inlet side of the DV to more than about 15psi. It leaks with a green spring, but with a blue spring it seems fine up to what I could test it.

blue spring?
what vac does that even open at?

test is simple. boost in side port + top @ same time.. pump it up and immerse in a bowl of water... and if all ok, bubble free

very revealing test
i have a shelf full of assorted DV's from assorted manufacturers...
only one is leak free.... guess which one

 

[16Klappe]

Interestingly a blue spring is 23-30psi, but regardless of putting a yellow, yellow and a shim, blue or red in my valve opens the same.

Might have an actuator fault somewhere, the arm is weak as **** but I see no loss on my boost gauge or logs. The yellow spring up gives more of a "kachoo" with no compressor stall audiable, where as the green gives much more of a "pffff".

I have been playing around with them and I do see boost loss with the green spring which I don't with yellow and a spring. Now that my valve is faced and lapped in I will go back to the green and experiment again.

On the S3 slayer a green spring would blow open and a blue spring would not open so I could only use a yellow. Same DV and the same springs, just on a different car.

 

[JD09]

So hang on. Bill, am I reading this right that the standard diverter valve on my S3 would have been just fine for stage 1 map? What's the reasoning for so many "you'll need a green cotton filter and 007p Forge with your stage 1 map" threads? Is this just purely marketing kak?!

 

[badger5]

filters may help breathing...
Factory DV's on older cars may be split/leaking and all "chirpy" noises when broken, and choice is after market DV's (choose x,y,z brand) or stick with OE

Much talked about on forums.... and regurgitated as required mods for tuning.

Improved breathing I am all for... hence my 80mm TIP, induction kit etc, proven gains.. etc
functional DV just needs to be that "Functional"

OE one holds 2bar and passes bubble leak test perfectly.

You pays your money and you takes your choice. OE DV aint sexy, bling or fashionable.

 

[badger5]

Interestingly a blue spring is 23-30psi, but regardless of putting a yellow, yellow and a shim, blue or red in my valve opens the same.

actually, if stiffer springs this is Impossible. It cannot open the "same"

stick a mityvac on it and see what vacuum is required to (a) lift it off its seat and (b) open it fully.
It will be impossible for varying spring strengths to the the same required vacuum for the above

you are arguing with someone who has tested these, different makes, different springs....... I kinda have an unfair advantage of knowing the tested facts.

 

[16Klappe]

actually, if stiffer springs this is Impossible. It cannot open the "same"

stick a mityvac on it and see what vacuum is required to (a) lift it off its seat and (b) open it fully.
It will be impossible for varying spring strengths to the the same required vacuum for the above

you are arguing with someone who has tested these, different makes, different springs....... I kinda have an unfair advantage of knowing the tested facts.

I know how much testing you've done with them and I know you're right, but in terms of me fitting the DV with a different spring and hearing and feeling difference I just cannot find any difference myself from yellow and a shim up.

I can only assume I have a lot of intake vacuum and no boost leaks in that sense which is making mine open strongly. I dunno. Any suggestions? Mine shouldn't open with a red spring in it should it?

 

[badger5]

lol... or you are flow little air, it matters not if it does'nt open much

{baits trap} Muah ha ha ha haaaaaa.... *cough*, this damned cough..

 

[Prawn]

hahahahahahahaha. I like this new antagonistic version of Bill, it's funny

Scientific testing vs ''it sounds the same'', hmmmmmmmmmmmmmmmmmm.....

 

[16Klappe]

hahahahahahahaha. I like this new antagonistic version of Bill, it's funny

Scientific testing vs ''it sounds the same'', hmmmmmmmmmmmmmmmmmm.....

I much prefer antagonistic light hearted Bill too, it's a welcome addition

My version of testing is pretty much the same way that you built your car haha

 

[Sam_]

You can always stop bickering and tell me why my cars pinking

Cheers for the guide though, probably about time I gave my 007 a clean.

 

[superkarl]

i've never understood, and still dont to this day, the need for different springs

 

[16Klappe]

i've never understood, and still dont to this day, the need for different springs

If you're running 21PSI and have a green spring rated for 15PSI, then there is a large chance that the spring won't be strong enough to hold the valve shut when you are on boost. It isn't as simple as 15psi inlet pressure though, that's the unassisted clamping force of the spring.

If you imagine boost filling the lower part of the valve, it will physically lift the valve open when that boost over powers the spring holding the piston shut.

If you look in this photo -

You can see a there is a lip, allowing boost to get under the valve.

The Baileys dump valve doesn't have this lip, almost eliminating the need for a stronger spring.

 

[16Klappe]

Well boys and girls, I'm a ****.

Swapped my 007p for an OE factory fit genuine DV and my car has never been quicker. Showing 5g/s extra from 3000rpm up to 7000rpm, so my DV must have been pretty leaky!

So my top tip of the day, sell your 007p on ebay and buy a stock DV. In future totally ignore more and listen to Bill haha.

 

[s3dave]

Well boys and girls, I'm a ****.

Just grabbed that quote incase 50% of the forum want to use it.....

 

[[Dave B]]

So what's the crack with the 008p then?

 

[16Klappe]

008p looks **** to me, having the rubber skirt around the bottom of the piston which is ready to get sucked into your TIP and mashed into the turbo as soon as it dries out and falls off.

Only seen pictures though so I don't know first hand.

 

[Jason.s]

Listen to others instead of barking back with I know best and you'll get far in life lol.

 

[badger5]

If you're running 21PSI and have a green spring rated for 15PSI, then there is a large chance that the spring won't be strong enough to hold the valve shut when you are on boost. It isn't as simple as 15psi inlet pressure though, that's the unassisted clamping force of the spring.

If you imagine boost filling the lower part of the valve, it will physically lift the valve open when that boost over powers the spring holding the piston shut.

If you look in this photo -

You can see a there is a lip, allowing boost to get under the valve.

The Baileys dump valve doesn't have this lip, almost eliminating the need for a stronger spring.

The thing is.......... brace yourself. lol
If a DV is fitted the correct way round, the boost is coming into the side port AND the top port, so boost is acting upon the piston from above and on the side. If everything was working fine and seating and sealing perfectly the piston is being held down by boost pressure + spring pressure.. So more boost would equal more clamping shut pressure..

Picking an arbitrary figure of 15psi DV spring (whether they are or are'nt is'nt important) and a car which produces 1bar boost you would expect to have Spring + Boost holding it shut. Up the boost to 2bar you would expect to have 2bar boost plus 15psi spring holding it shut.. eg the boost going up is helping keep it closed. Why the need for stiffer springs?
The side effect of stiffer springs is it effects how easy the DV will open, ie what vacuum is required to "fully" lift the piston.. Too stiff a spring and the piston wont open as much or if at all in extreme circumstance. Air is both compressible and stretchy... so the vac lines volume, the DV's chamber volume all need to be "sucked" to take up the slack as it were before being able to pull up a piston against its spring.. Slower acting, needs more vacuum, and possibly not opening as much. These not being good attributes for a DV imho

The bubble tests and vacuum tests show these kind of differences..
An easy to open, minimal vacuum, will open faster, and fully compared to a stiffly closed one.. 1.8t's only develop a certain amount of vacuum, and old tired ones less again.. so for me, an easy low vacuum opening DV, which seals fully under boost is the goal.

 

[colicabcadam]

dougs (MRC) 700 bhp uses OEM vavles, plenty of chaps on audisrs with 600+ horses use OEM valves, says it all really

it's an expense with no improvement, in a quote i had from amd, they said my car would need them, my car is fine with the power it has on standard OEM's

 

[superkarl]

If a DV is fitted the correct way round, the boost is coming into the side port AND the top port, so boost is acting upon the piston from above and on the side.

this is why i've never understood the need for different springs

 

[paultownsend]

After reading on the Google, 996 twin turbo Porsche's run two 710n OE Bosch valves and they are the preferred choice up to silly boost/power with ease.

I too can only see DV to bleed boost if installed incorrectly

 

[A3 T]

Do the standard DV’s that are fitted to the S3 have the same part numbers as the A3 ?

 

[Sam_]

Anyone tested the Tial QR? Supposedly works well. Certainly looks the part. How easy is it to test? Happy to do it when mine gets there I'm hoping it's quieter than a 007p but doubtful, guess it's more down to the filter setup.

 

[badger5]

ker ching $$

 

[colicabcadam]

people seem to forget that bosch have more money for development and testing than any of other manufacturers combined, i have always kept with oem

 

[paultownsend]

Bosch 710n is £35 all in from TPS with club discount.
If I knew then.......

How do you lap in a piston on a DV?

 

[Sam_]

ker ching $$

Yeah, I managed to get one cheap over here. Usually like $300 or so. I'd have to get a Bosch valve imported anyway (mine never had one).

What does your racer use?

 

[badger5]

people seem to forget that bosch have more money for development and testing than any of other manufacturers combined, i have always kept with oem

LOL like thats an endorsement..

they also make MAF's.......... and coil packs.....

ying and yang perhaps

 

[badger5]

Yeah, I managed to get one cheap over here. Usually like $300 or so. I'd have to get a Bosch valve imported anyway (mine never had one).

What does your racer use?

a leaky supersize currently. It has a new atmos valve to try 50mm one, but not had time to weld the pipe fitting for it as yet

 

[A3 T]

I just come across this DV test on another forum (all credit goes to the original poster) and though it was interesting......



mike01s4's Audi fitment Diverter Valve Testing:

---

by Mike Shimon (VAST Performance)

All tests were done off the vehicle.

Diverter Valves tested:

1. Stock Audi S4 turbo diverter valve: Bosch 108 pn: 0280142108 (audi pn: 034145710A)
2. Forge diverter valve with aluminum piston, soft green spring, and updated o-rings
3. Bosch 110 pn: 0280142110
4. Bosch 114 pn: 0280142114 (Audi pn: 06A145710N) ​

Some purposes of test:

1. analyze the piston displacement (travel) versus vacuum pressure
2. analyze if flow rates differed between valves
3. determine the pros and cons of each valve ​

Some test equipment:

1. Linear transducer accurate down to 0.0001 inches. % FSO error unknown.
2. Rigid clamping fixture for securing DV and measuring piston displacement
3. Vacuum pump with analog mechanical vacuum gauge. Accurate to +/- 0.25 in Hg.
4. stopwatch
5. graduated cylinder (20 fl. oz)
6. varied pressure constant fed water source
​

To obtain the data for displacement(piston travel) versus vacuum pressure, I applied a vacuum in a slow fashion in ~0.5 in. Hg steps. The vacuum pressure was increased until the piston would not travel any further. I also noted whether or not the valves stuck, or had an inconsistent pull, or leaked. I took two to three trials for each valve, and the measurements were quite repeatable. I obviously could not simulate the ON-vehicle pressure fluctuations and measure displacement.
The forge valve needs the most amount of volume displaced in order for the piston displacement to achieve a full open state. This is a point where the Bosch bellows style diaphragm design is superior. I am making an educated guess that the Bosch will respond quicker to opening due to this fact, albeit, it will probably be only milliseconds faster. Also, it looks as if the 110/710N will take a longer time to open, but, just because it comes open a few in. of Hg later, the typical vacuum pressure developed can be ten times this difference. So there should be no worries with a slow response time with any of these Bosch valves.
One thing that I could not check, is the reaction time for the valve to close after a full open state. But, since the spring rates are now apparent for each valve, all other things equal with the Bosch's, you can see that the 110 and 710N will close the fastest. The forge's closure rate will not only depend on the spring rate, but also the grease used and temperature. With insight from this plot, the forge will close the slowest, then the stock 108 is a bit faster, then the 110 and 710N are the fastest.
Between the 110 and the 710N, you can see that they are exactly alike. Unless Bosch changed the materials used in fabrication for the diaphragm, these valves are totally equal. I did not destroy the valves to inspect the differences since I was using other people's parts and it would cost around ~$50 to do so.
I also checked the ability to open under a cold test of 20 degrees Fahrenheit. The Bosch valves would stick, but only occured once, and only once, on an initial applied vacuum. So, cold runs in the vehicle should never even be a problem. The forge did not stick. I did not know what the relative humidity was when I did this.
As far as diaphragm or piston leakages are concerned. None of the Bosch valves leaked. How they perform after many cycles in an engine's environment, I could not say, but they will not leak unless the diaphragm tears or if the housing cracks. It is very easy to check leakage. All that is needed is an applied vacuum and a little time spent on looking to see if the vacuum drops with time.
On the other hand, the forge will leak if not sealed properly or contaminated by debris. From the opened valve picture, you can see where the Forge can leak. All that is needed is a cleaning and a slight medium to heavy weight grease to seal this. With the Forge, I noticed anything from a near perfect seal, to a low of ~1 psi loss per every 5 seconds and then much worse as a small particle contaminated this seal.
On to the flow rate tests, I found that the bosch and the forges still have the same flow rates while testing with a complete inner fill of water flow. With the valves completely opened, each valve could fill 20 fl. oz in approximately 8 seconds. Of course, even as I put restrictions on each valve, maintaining the same inlet pressure, each valve still achieved the 8 second value, obviously with a greater exit speed.

Summary

FORGE:
Pros: can maintain it at any time can replace spring with a higher rate virtually a lifetime part smooth/open air flow path when compared to bosch, BUT, still has the same flow rate up to a typical working pressure comes with viton O-rings which have superior temperature and wear characteristics	Cons: price fitment, due to larger size, is not as good as bosch(the passenger side vacuum hose can easily kink if not installed carefully) slower response time can have an inconsistent piston travel if not lubed properly or not maintained possible sealing issues if not kept clean

BOSCH 108:
Pros: price slightly higher spring rate than forge quick response time for opening no fitment issues no warranty issues	Cons: cannot inspect or service valve completely possible problems noted with many users for diaphragm tears max piston travel, for its design, is not as large as the 110/710N air flow path not as smooth as forge, but still has the same flow rate up to typical working pressures

BOSCH 110/710N:
Pros: price larger piston travel compared to stock with a small bellows volume: quick response time for piston pull with a higher spring rate: quick response time for piston closure possibly more durable than stock no fitment issues no warranty issues	Cons: cannot inspect or service valve completely air flow path not as smooth as forge, but still has the same flow rate up to typical working pressures

2/25/02

Update: 03/05/2002 This new graph includes the piston travel for different spring rates with the forge DV. there are 3 springs: green(comes standard) = softest, yellow = medium, and blue = stiffest. for all practical purposes, you can see with the yellow spring that it performs like the stock 108, and with the blue spring, it performs like the 110 or (114)710N valve. Basically, the downside with the stiffer springs in the forges as compared to the bosch is that you are slightly reducing the response time of the valve even further. This is due to the fact that the bosch valve needs a smaller volume of air displaced to pull its piston open or force it closed.

mike01s4's Audi fitment Diverter Valve Testing Part 2:

---

by Mike Shimon (VAST Performance)

Did some more BPV checks....some interesting/conclusive info... thanks KENT L & LOSGATOSS4!!!!!!! for sending the samples for my destruction last time I posted about all the different valves (bailey excluded) and the only thing we couldn't talk about was the internals of the bosch valves. So the point of this is to compare three Bosch DV's and note their constructional and material differences and similarities and qualities.
So here it goes,
Valves checked:

Bosch. 110 (Porsche)
Bosch. 114 (VAG. 710N)
Bosch. 108 (VAG. 710A)
​

I sawed off the top (piston chamber side) of each of the above valves.
From my previous post, all signs indicated that the 110 and 114(710N) were the same exact valve due to the exact same spring rate, max displacement and piston seating, etc. Now, I also noticed that the diaphragm was made of the same exact polymer material with the same exact thickness and the same construction with the same brass stopper. So, even though there are two different part #'s, they are totally the same.
I cut away sections of the diaphragm and mic'd them up. The diaphragm thickness for the 110 and 114(710N) is as follows: 0.0200" - 0.0205"

I then took apart the stock 108(710A) valve and analysed it in the same manner. The brass piston stop is taller, (hence, the lower displacement value as noted in my first tests). Also, the diaphragm material is thicker: 0.0240" - 0.0245". This is substantially thicker than the valves that we are all upgrading too, and it mislead me for a moment. But, as I pulled away sections of the diapragm for testing, I noticed that the stock material tore very freely, while the 110 & 114(710N) was more elastic and resisted tearing even along an initial cut. I then applied the same force to the piston hats for each valve and noticed that the stock valve diaphragm just gave way very easily and I was able to rip it right off while I was struggling to tear the 110 & 114(710N).
Also, with the upgraded valves, Bosch cut some costs with reducing the thickness of the brass stopper and most likely reduced costs with using a thinner, but stronger diaphragm material. The last difference is, of course, the higher spring rate and larger piston displacement with the 110 & 114(710N).
(shorter brass piston stop for the 110 & 114/710N allows ~0.050" more travel)

(thicker, but weaker stock material on top compared to the 110 & 114/710N thinner/stronger material on the bottom)

(valves disassembled. note how i was able to rip the diaphragms right off with the stock valves)

So that's it folks, you don't have to guess anymore, when buying these valves, I hope!

 

[s33nyboy12]

I think forge need to do something about there dv leaking. End of the day it is sold and marketed as an " upgrade" and if it is simply not as efficient as the standard one (oem Bosch) then that isn't good enough. I am surprised by bills testing results it's interesting to know.

Sean

 

[Sam_]

Interestingly Tial provide a sheet with their QR stating that the spring has nothing to do with boost, only vacuum. The boost acts on the bottom of the piston on the QR, which you can do on the 007p but it makes it sound terrible.

 

[A3 T]

To be honest i think we put way too much though into these DV valves for what they are.

Having said that i would still want to try out a 007p so if anyone has one going cheap then send me a pm....lol

 

[badger5]

great find... Never seen this before.. Boy that guy did some thorough testing.. Only thing missing was other after market DV comparisons..

confirms the testing I have done.........

internal volume effecting response..
stronger springs slowing response further..

Remember folks air is Compressable, and is also Stretchy under vacuum... More Volume to pull again, slower response, and this includes lines going to the DV as well as internal DV volumes. Silicon in a forge shim and you immediately shrink its internal piston volume for example.. which can only help..
you get the idea etc..

 

[mrfaststu]

I just struck lucky been down to the yard I work at on saturday and a lad had just taken a engine out of a A3 and it was fitted with a forge 007p that was quickly removed into my possession will be checking it over in the morning and trying it on my car. just got to wait for a fmic set up to turn up and that will be mine as well not bad for freebies

 

[JudderMan]

Hmm after a different thread and speaking to Tufty and having read this again I might take my 007 back. I must have missed this thread but read others and decided that it was worth buying one. **** it, gonna get my monies back and get an OEM.

 

[Birdy]

this seems like a good place to ask. iv seen somewhere on the forum someone had fitted their DV backwards? im sure this cant be a good idea as surly it must put pressure back in to the turbo? but even so, nobody said that this was a bad idea and they knew they had done it? is there any reason/gain for doing this or is it a bad thing to do?

 

[badger5]

nope it does'nt put pressure back in the turbo reversed


it changes the way the DV vents and it boost is helping push the wg open or not... and alters the sound...

 

[Birdy]

ok so its not going to cause any damage but it is kind of pointless unless your looking for a different sound. i tryed this and found all it did to mine was make it back fire? although i didnt put the vac pipe on the top (didnt realise it had fell off) and it started to flutter. my engine is APY im unsure if that makes a difference or not as i dont no what my turbo is just know its the standard one. anyway i think after all this ill just leave it how it was ment to be lol. cheers again badger im learing more now than i could if i was in a garage lol

 

[16Klappe]

There are so many "don't know's" in there that I think you should just put it all back to how it was and leave it alone