dump valve help needed.

[850t5]

Can I blank off the pipe that runs from the recirc until I can get the blanking plate on?

[p fandango]

Can I blank off the pipe that runs from the recirc until I can get the blanking plate on?
i have heard of someone using a one-way valve (think it was from a screen wash system) to trap air in the pipe keeping the recirc valve closed. It will need pressure in the pipe to stop it being forced open when the turbo comes onto boost, you can't just remove the pipe or the valve will always open

[850t5]

Cheers mate. I'll just wait and get it done properly then lol

[p fandango]

Cheers mate. I'll just wait and get it done properly then lol
no worries, yes best do it properly mate. You might be able to run both the recirc & the dump valve with no problems some have, but your aftermarket won't be as loud till you get the recirc blanking plate on

[gmain1967]

no worries, yes best do it properly mate. You might be able to run both the recirc & the dump valve with no problems some have, but your aftermarket won't be as loud till you get the recirc blanking plate on

That's how I ran my Forge valve on my T4, as one of the bolts would not come off the recirc valve very easily. Ran it like that for a couple of weeks before I had time to get car on ramps and get the bolt removed. It works but as Pfandango says, the dumpvalve won't be anywhere near as loud as it should be.

[p fandango]

It works but as Pfandango says, the dumpvalve won't be anywhere near as loud as it should be.
nearly sounds like i know what i'm talking about :wink: lol

[Tomcat]

nearly sounds like i know what i'm talking about :wink: lol

Nah... don't worry, no one would believe that,lol.

[p fandango]

Nah... don't worry, no one would believe that,lol.
glad to hear it lol

[gmain1967]

glad to hear it lol

Come come, you're being way too harsh on yourself!

[p fandango]

Come come, you're being way too harsh on yourself!
you've got to have a good laugh & banter mate, poor JelT5 isn't even safe off the forum because i take the p**s out of him on Facebook now lol

[JelT5]

you've got to have a good laugh & banter mate, poor JelT5 isn't even safe off the forum because i take the p**s out of him on Facebook now lol

That's just sour grapes on your part due to your cr@p scores on bejeweled :D

[scr8pdo]

I was thinking of putting a dump valve on but I thought the cars already had one, is there any advantage to fitting an aftermarket dump valve apart from the noise? I do like the noise, someone said it would be beneficial as you wont be putting hot air back into the inlet side, venting it to atmoshpere instead, others said you can lose boost pressure fitting aftermarket D/V any ideas?

[gmain1967]

I was thinking of putting a dump valve on but I thought the cars already had one, is there any advantage to fitting an aftermarket dump valve apart from the noise? I do like the noise, someone said it would be beneficial as you wont be putting hot air back into the inlet side, venting it to atmoshpere instead, others said you can lose boost pressure fitting aftermarket D/V any ideas?

There are different schools of thought on this. The original recirc or diverter does indeed put excess boost back in to the system, which will help keep the turbo spinning and reduce lag if you go on the power again.

A dumpvalve (or atmospheric valve) vents to atmosphere and the pressure is lost entirely. This can supposedly cause issues with MAF sensors, where the air that has been measured and the ECU knows should be in the system is lost, and the ECU tries to compensate. I run a Forge on my T4 and have no issues. Dumping at higher boost levels will help prevent turbine stall.

As regards losing boost pressure, that can happen with the original recirc valve and/or a dumpvalve. A weak spring, or a failed internal rubber seal will both cause this, as will a split pipe or poor connection.

If running higher boost, pressure can also be lost if the spring is not strong enough to cope with peak boost and in effect opens early, thus preventing boost from reaching it's maximum.

If you want the noise, just go and do it but my advice would be as follows. Remove the recirc valve and blank it off. ONLY fit a dual piston type valve. Change the boost hoses to better quality SFS or Samco or similar, or use aluminium pipe also. If you do use pipe, make sure that the ends are "lipped" to aid seating of the hoses. Use heavy duty clamps for holding everything together, rather than jubilee clips. And locate the dumpvalve as close as practically possible to the throttle body.

Enjoy!

[scr8pdo]

I seen you can buy a fitting kit for the d/v but i have done a reverse flow mod myself so the hose in the fitting wont work, I looked at the conversion kit for the reverse flow i/c and is on special offer from parts for volvos for £500 ODD! Insane amount of dough for a few pipes so looks like i wont be fitting one after all unless someone else has the answer, also i really dont want to fit one if there is no real performance benefit in anyones experience

[gmain1967]

At that price, I'd leave well alone. And in terms of performance, there is no gain to be had.

[p fandango]

That's just sour grapes on your part due to your cr@p scores on bejeweled :D
you all cheat lol

[850t5]

I've split the pipe going from the manifold to the recirc and used a 3 way connecter to put the dv in line. It's quiet as hell as you've all said. I'll get the plate on Monday. It's funny to give it some welly up to 30mph and getting the woosh noise then watch all the pedestrians try to work out where its coming from. They're all looking for a rs turbo or such like lol Even my mate laughed at the idea of having a dv on a Volvo.