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-   -   Dump valve delete (https://www.scoobynet.com/general-technical-10/804325-dump-valve-delete.html)

subaruturbo_18 09 December 2009 01:52 PM

Dump valve delete
 
OK, so i am bored today and wanted to try this for a bit of a laugh.

My main intentions were for the sound it creates. The rally chirp shoud.

Am i right in saying the correct way to do it is to block off all the pipes that would connect to the dump/recirc valve, and then block off the port on the intercooler?


Once this is done i was under the impression that when acceleratiing and then releasing the throttle cable i should get the chirp sound when i would normally hear the 'dumping' sound..


Can anyone shed some light on this please?

N_Scooby 09 December 2009 02:20 PM

A temporary way to try this is to just remove the vac pipe to the DV and block the end with a bolt that is slightly larger that the vac pipe ID. Removing the vac pipe will stop the DV opening to dump and it will act as a stopper/bung.

dazdavies 09 December 2009 02:37 PM


Originally Posted by N_Scooby (Post 9090303)
A temporary way to try this is to just remove the vac pipe to the DV and block the end with a bolt that is slightly larger that the vac pipe ID. Removing the vac pipe will stop the DV opening to dump and it will act as a stopper/bung.

The vac pipe keeps the dump valve closed.
If you remove the vac pipe the dump valve will open even easier and will leak boost.

The only way to do this is to remove the dump valve completely, block off the pipe that returns to the inlet ( you will already have done this if you have a VTA dump valve) and put a shaped metal plate on the intercooler in place of the dump valve and ensure its sealed and wont leak.

It's not advisable to do this on a VF series turbo.

chrisdicko 09 December 2009 03:53 PM

Depends which VF though. The 35's can handle it fine...

subaruturbo_18 09 December 2009 04:44 PM

Mines a UK classic so td04. Earlier today I made a plate with steel, it was only 0.5 mil thick so I tripled up, but I don't think the seal was great.


Are we agreeing on the fact that the seal on the intercooler needs to be tight with no air leaks atall or I will not get the chirping I want?

chrisdicko 09 December 2009 04:55 PM

Yeah it needs a good seal.

It will make a lot better noise if you have a CAIK as well.

Splitpin 09 December 2009 04:56 PM


Originally Posted by subaruturbo_18 (Post 9090549)
Are we agreeing on the fact that the seal on the intercooler needs to be tight with no air leaks atall

Of course. Otherwise it'll leak air under boost which is highly undesirable.


or I will not get the chirping I want?
You won't get the "chirping you want" no matter what you do, if you're expecting it to sound like a WRC car. They're running big turbos, over 3 bar boost, metal intercooler pipes, an air restrictor and a very short (and open) pre-compressor induction tract. All of those things amplify the noise and you don't have them on your roadcar. You will get some noise on liftoff, but it will be very anaemic in comparison - to the point where you'll struggle to hear it much of the time.

Also, it's difficult to tell from your avatar, but it seems you have a V or W reg, and hence MY99 or MY2000 car. If so, running without a DV will damage your airflow sensor quite quickly, and the consequences of that will be very unfortunate for your engine if you don't spot it before it becomes serious.

subaruturbo_18 10 December 2009 09:43 PM


Originally Posted by Splitpin (Post 9090582)
Of course. Otherwise it'll leak air under boost which is highly undesirable.



You won't get the "chirping you want" no matter what you do, if you're expecting it to sound like a WRC car. They're running big turbos, over 3 bar boost, metal intercooler pipes, an air restrictor and a very short (and open) pre-compressor induction tract. All of those things amplify the noise and you don't have them on your roadcar. You will get some noise on liftoff, but it will be very anaemic in comparison - to the point where you'll struggle to hear it much of the time.

Also, it's difficult to tell from your avatar, but it seems you have a V or W reg, and hence MY99 or MY2000 car. If so, running without a DV will damage your airflow sensor quite quickly, and the consequences of that will be very unfortunate for your engine if you don't spot it before it becomes serious.

Problem solved. I thank you for advice.

subaruturbo_18 10 December 2009 09:44 PM


Originally Posted by chrisdicko (Post 9090578)
Yeah it needs a good seal.

It will make a lot better noise if you have a CAIK as well.

CAIK

WhiteWagonMan 15 December 2009 12:19 PM

CAIK=Cold Air Induction Kit mate.:thumb:

japjunkie 15 December 2009 10:32 PM

if you are running a recirc valve reverse it and that will give you the noise you want

AshMurc 15 December 2009 10:45 PM

my wagon (TD04) came with a hks DV which removed a while ago as it was a bit much. blanked off the pipe and vac hose that formally connected to the DV. You can certainly hear the air being forced back through the impellar blades no probs at all (standard air box, just a fast flow filter), but no, it doesn't sound like a rally car! oh well! does sound pretty cool under "middeling" boost though, and i certainly prefer it to the HKS which was ott for me.

jvivok1985 15 December 2009 10:50 PM

good way to wreck ur maf an turbo lol

subaruturbo_18 16 December 2009 04:40 PM


Originally Posted by japjunkie (Post 9102312)
if you are running a recirc valve reverse it and that will give you the noise you want

How do i do this?

Splitpin 16 December 2009 04:55 PM


Originally Posted by subaruturbo_18 (Post 9103359)
How do i do this?

You can't on an MY99+ (earlier ones were reversible), and even if you could, for reasons above, it still doesn't give you "the noise you want".

jvivok1985 16 December 2009 05:36 PM

why dont u fit an induction kit? that'll give u the spool an chatter noise ur after? not as loud as a rally car, but u wont get the noise thru the airbox

Splitpin 16 December 2009 05:45 PM


Originally Posted by jvivok1985 (Post 9103463)
why dont u fit an induction kit? that'll give u the spool an chatter noise ur after? not as loud as a rally car, but u wont get the noise thru the airbox

If the dumpvalve hasn't been blocked off, an induction kit alone won't cause compressor stall, it'll just make the car's normal induction noise a bit louder.

Even if it did, the main reason not do do this simply in the pursuit of "noise" is the risk to the accuracy of mass airflow measurement, whether by the loss of the resonator, or fundamental alteration of the airflow to voltage curve, or vibration damage to the sensor, which is a particular problem on MY99-00 cars.

jvivok1985 16 December 2009 06:37 PM

no it wont cause the stall, yeh some of the induction kits like the powertec one makes quite a woosh as u boost, and as u let off, I had it on mine when i had to bung the dumpvalve off whilst i was waiting for a new dumpvalve, made a nice chatter back thru the intake.

Yeh im not advising him to do it lol, i think its the fact the compressor stalls an the air it was pulling in has nowhere to go besides back out where it came from! probably confuses the maf

jd5217 16 December 2009 06:40 PM

get rid of the maf then.

mickywrx 16 December 2009 08:30 PM

I'm going back to a re-circ.

The noise of the compressed air going back through the turbo/air filter gets on my tits when changing gear of lifting off, at anything over 0.5bar of boost.

Sounds like a cloud farting. :wonder: :lol1:


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