DV Relcation - anyone got fitting instructions/guide?

Pabs

Active Member
May 3, 2004
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erm confusing myself here - the long hose from original location is connected to the BASE connection which comes from the TIP. The side hose is plugged and then the dv side is connected to the intercooler hose, as per pic above.

This means it is in the correct way around?

The forge guide (link in 2nd post) shows the dv being fitted the OTHER way around. So do Forge recommend fitting the dv in reverse? or is this just a mistake in the guide?
 

m0rk

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May 19, 2001
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I think that's the right way around pabs - that's the same way round as the LC I fitted one to 'the right way around'
 

Feel

Veedubya 'velle
Jun 12, 2003
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Looks the right way round to me too (not that I really need to confirm what the m0rker said).

Glenn's description seems wrong to me :confused: - boost comes in at the side, on the Leon anyway.

Interestingly, I have heard the same chatter/flutter that you describe. Low revs, boost builds, lift off and "tchtchtchtchtch". Can remember now whether that's with the DV relocated or not, I've changed it that much.
 

m0rk

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Feel - on jonah's LC it chattered, so we swapped the spring stiffness, to a stiffer one - and it's worked

theory was that it was bouncing rather than just closing like you want.
 

Pabs

Active Member
May 3, 2004
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at the moment i run the 2nd spring - the std spring used to be in and it chattered, so I swapped it over.
Still does it occasionally, but when I spoke to Bill he says that the chatter is because the spring is too stiff :S :confused:

First thing for me to do is to relocate it. Then I might swap back to the original spring, depending on the situation.
 

Feel

Veedubya 'velle
Jun 12, 2003
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m0rk said:
Feel - on jonah's LC it chattered, so we swapped the spring stiffness, to a stiffer one - and it's worked

theory was that it was bouncing rather than just closing like you want.

Cheers - I can't remember what spring I'm on, but I think the next one is the red one; some comments I'd read put me off putting it in...

It does seem to me that your theory is right, and tbh it only does at low revs/high boost/lift off - so I'm not too bothered.
 

m0rk

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May 19, 2001
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Yeah - this was 1.35 bar(ish) and we only used the yellow one..

Can't recall what the LCR does (1.55?)

It still makes a whoosh noise, but with the green spring it was more of a chuff chuff chuff chuff

I like my sounds-by-words
 

Pabs

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May 3, 2004
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Feel said:
Cheers - I can't remember what spring I'm on, but I think the next one is the red one; some comments I'd read put me off putting it in...

It does seem to me that your theory is right, and tbh it only does at low revs/high boost/lift off - so I'm not too bothered.


Ditto - Red is a no-no for me after reading about it, and i dont see why it should need it anyway.

Exactly the same situ as me with the noise - but I was told to be very wary about it as it isnt a good noise.
In fact, here are the immortal words of Bill:


Stonger springs will promote chatter as the piston in the DV is made to be much harder to lift under vacuum, so wastegate chatter flutters.... In effect you have stopped the DV from working at all.

Check vacuum lines to the DV also... some are showing signs of aging and are splitting and cracking. (check DV too... it might be working or stuck perhaps in the cold weather)
 

Bassedout

Back to Blue with a Turbo
Feb 27, 2005
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low revs/ high boost / lift off.
It does it in mine too...... DV in stock position and using a stiffer spring. Yellow I think.

Daft question but how does the DV work anyway??

cheers
Phil
 

Glenn

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Oct 15, 2001
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Feel said:
Looks the right way round to me too (not that I really need to confirm what the m0rker said).

Glenn's description seems wrong to me :confused: - boost comes in at the side, on the Leon anyway.

Interestingly, I have heard the same chatter/flutter that you describe. Low revs, boost builds, lift off and "tchtchtchtchtch". Can remember now whether that's with the DV relocated or not, I've changed it that much.

For reference, I call the top of the DV the bit with the small nipple.

If you stick boost in to the side of the DV, then you can't push the DV open with boost pressure because the body of the piston can't move laterally. In that case, why would you need a stiffer spring? All it would do is slow the response of the DV down by, as Bill says, resisting the suction from the vacuum at the top of the DV. Think of the DV spring as a damper, like those on your suspension, it's purpose is to smooth the transition as the DV opens, so that it's not slamming wide open at the slightest pressure differential across the DV. It also prevents the DV opening at the onset of boost where the manifold pressure may lag the pressure at the base of the DV - this doesn't apply if your piston DV is reversed.

Take a look at a stock Bosch DV, if you run it reversed (boost in the side), you can see that you are applying pressure to a soft neoprene diaphragm that has give in it. Any wonder that they tear? That makes no sense to me, what does make sense is to apply pressure to the metal plate at the base of the diaphragm? It also makes no sense to have a device that operates via pressure differential only to hook the opposing pressure sources up at 90 degrees to each other.

In theory, I absolutely agree with Bill that overly-stiff springs are a bad idea because they make it harder for the DV to operate and why have a DV at all if we're going to hinder it? In practice though, I find my car is much nicer to drive with a stiffer spring but it's still not OEM perfect. I've experienced this "chuff-chuff" effect and my theory is that the DV isn't opening wide enough or for long enough (due to the stiffer spring) to satisfy the ECU (MAP isn't dropping off fast enough with respect to TPS rate of change?) so the ECU is pulsing the N249 to open the DV and there's a 'tug-of-war' going on for control of the DV piston between the spring & N249.
This would occur whatever the DV orientation, but with the DV in what I believe is the correct position (boost from the bottom), the boost pressure will "assist" the vacuum at the top in opening the DV against the spring preload. I'm going to try bypassing the N249 to test this theory.
 
Last edited:

Feel

Veedubya 'velle
Jun 12, 2003
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Midlands
But, the stock DV is mounted with the boost coming in the side :confused: So, the boost pressure doesn't push the DV open, but vacuum must pull it open?

So, really, what is "reversed"?
 

RickC

BUILT NOT BOUGHT
Dec 23, 2004
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when i tried the atmos one the spring was too weak so it was just tsshhhhhhhh ing all the time so i put in a stiffer spring it sorted the problem but it made the chatter noise, i got rid put the forge one on and it was sorted, i think yull find the sprin is too stiff and the Dv is not working ,hence the air that is meant to be vented out is pushed over the blades of the turbo making that chatter noise.
leave the dv that way and change the spring back to stock, mine works fine standard.
 

Tallpaul

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Jul 2, 2005
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Pabs, thats DV relocation photo is from my car. The DV is plumbed the 'right' way round.
 

Glenn

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Feel said:
But, the stock DV is mounted with the boost coming in the side :confused: So, the boost pressure doesn't push the DV open, but vacuum must pull it open?

So, really, what is "reversed"?

Just had a look and ETKA seems to agree with you. Run the other way, boost pressure can only push the DV open when there is a pressure differential across the top (manifold vacuum) & bottom (boost) of DV in which case it's supposed to be open and it can overcome the spring preload.

If boost is supposed to go in from the side, then (a) it tells me why so many Bosch DVs fail and (b) the DV spring only needs to be as strong as the Bosch preload (as N249 duty is based on that) - my Forge green is softer than Bosch - maybe why Yellow works better?

Perhaps we should avoid the use of the word chatter as it seems to confuse with wastegate chatter which isn't what I'm talking about - DV oscillation/harshness/overshoot,etc.
 

Pabs

Active Member
May 3, 2004
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right guys

Firstly, Tall Paul - thought it was yours. Remember you selling it. You put the T-piece in a strange place on the hose didnt you? I couldnt use it like that on mine, so I cut my own samco up and used that instead. Well, I was told by the person I bought it off that it was your photo, so can only assume i now have your kit... Sorry if I am wrong here.

I have put my DV in the same way as the photo above. Took me bloomin ages to install the kit, trying to get all jubillee clips done up etc.


First question - The hose from the kit I bought second hand had a lot of black gunk in it - between throttle body and intercooler.
IS THIS BAD? NORMAL???


Anyway, a test drive shows a very different sound to before - I used to get a much louder echo down the CAI I have, and now its much quieter and shorter in length, Ie Tssshh instead of TSSSSSSSHHHHHHH. (lol)

Only 1 thing I am worried about. Now when i boost past 15psi to max (20psi), I can hear what sounds like an airleak around my boost gauge... Gauge still reads same values as before but it just sounds like somehow this has created a leak in my gauge somewhere???
Any ideas?
 

Tallpaul

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Jul 2, 2005
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no idea if it's mine mate. all i know is, that's my photo.

i put the t-piece in the middle of the hose and facing the engine so that the DV would sit a little neater above the intercooler hose.

It's gonna be a lot quieter because the black ribbed hose and the volume of air contained in it will 'absorb' a certain amount of the noise.
 

Pabs

Active Member
May 3, 2004
5,936
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Basingstoke
no worries mate, its all fitted and working now.

I have noticed the "ch ch ch" noise once already with the dv relocation on. So next thing is to drop back to the original spring. At the moment I have a yellow spring with no shims in it.

Gonna revert back to the green and see what happens.

If anyone can confirm which way round the dv should be, let me know. I have boost coming into the side (from the intercooler to side on dv) and as you say it doesnt make much sense - the piston wont move laterally.... perhaps it should be the other way around?
 
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