where do you get the dump valve for the 2.0 turbo??

**bobtheboss78** · 22nd November 2007, 16:43

just as it says i read the fittin guide and seen a few local with dump valves fitted but which ones do you buy?? thanks and where from lol

**mark1319** · 22nd November 2007, 16:59

IIRC it's forge motorsport that do the kit for the 2.0T

**integrale** · 22nd November 2007, 18:35

I know the one that pops up in the integrale world is the Audi TT one....

**nikroc** · 22nd November 2007, 18:43

Slightly off topic BUT what does a dump valve actually do? Iask because my new 2 litre t has one fitted whot are the gains?

**integrale** · 22nd November 2007, 18:55

Most production turbocharged engines are fitted with a dump valve. This is to vent away excessive turbocharger boost pressure when the throttle is closed.
The dump valve is the black plastic saucepan shaped object that you will see connected between the intercooler and the air inlet hose to the turbocharger. You will also see a small hose leading from the top of the valve to the inlet plenim on the engine. Inside the valve is a rubber diaphragm and a steel spring, with a small insert to support the diaphragm where it seats against the dump valve body.
The dump valve has basically two operating conditions; throttle open, and throttle closed. When the throttle is open, the boost pressure coming into the valve from below the diaphragm is equalled by the pressure onto the top of the diaphragm that comes via the small hose from the engine plenim chamber. As the pressures are equal, the spring holds the diaphragm onto its seat, and prevents the pressure venting away. When the throttle is closed, the pressure coming into the top of the valve is significantly reduced, (often to a vacuum), and the pressure below the diaphram lifts it away from its seat, allowing the excess pressure to vent away. As the throttle is reopened, the pressures again equalise, the spring pushes the diaphragm onto its seat, and the boost pressure cannot vent away.
Without a dump valve, when the throttle was closed, the build up of boost pressure would be immense, very similar to closing a quickly flowing water tap. This excess of pressure, (which could be over five times the running boost pressure), would put the components of the system under a great strain. It would try to burst the intercooler and pipework. More significantly, it would put a large strain on the turbocharger itself, firstly stalling the compressor shaft, then trying to force the compressor wheel out of the turbo, against its bearings.
So, the dump valve prevents mechanical damage to the intercooler & turbo pipework, prolongs turbocharger life, and prevents excessive turbo - lag that would be caused by the compressor shaft stalling.
The only thing that can go wrong with a dump valve is that the diaphragm can become holed. If this happens, it will not seal, and the boost pressure leaks away all of the time. This will cause the turbocharger to work harder to overcome the leak, (turbochargers will work as hard as they have to, to give the required boost), and this will be noticeable to the driver, as a lack of boost response.

Borrowed from another site but I hope it helps a little....

**Duncan** · 22nd November 2007, 18:58

Unless you, or the previous owner, have added it, yours will as standard have a recirculating vent to air valve (dump valve). A dump valve (atmospheric) simply gives you that enhanced psssht noise when lifting off under acceleration/changing gear.

Edit: Also

**nikroc** · 22nd November 2007, 19:09

Wow..talk about quick response! Thanks for the information integrale.I have a nice shiney blue dump valve fitted so i guess i gotta 'atmospheric' dump valve fitted. Thanks Duncan.
Is it right that the engine management light is on ? The dealer and auto electrician said this was due to the valve and that i had to live with it!

**integrale** · 22nd November 2007, 19:44

Sounds like a lazy answer from the dealer..

But then again it might have something to do with the engine management, I'm sure others that have had them fitted will let you know if theres is on or not.

Tim

**mark1319** · 22nd November 2007, 19:48

There is one or two others with DV fitted and have not reported any lights coming on.

**Duncan** · 22nd November 2007, 19:55

As above, sounds like a lazy answer. Rickyroo had a Forge one (I think) fitted and I'm sure he had no lights up due to it. Maybe something hasn't been fitted quite right and is causing the issue. I guess the only way to see if it is the DV is to take it off for a bit.