Hi, im interested in getting this:

http://www.compbrake.com/dump-valves/recirculating-dump-valve-for-all-vag-1-8t-engines.html

Just a few questions, would it be ok for a 1.9 TDI ( i know it sas 1.8 engines) and if not is there a recirculating one that will fit?

Thanks in advance.

I believe the 1.8T its referring to is the petrol engine, not the 1.9 tdi.

Edited 7 May, 201214 yr by hutchysrs50

As far as I`m aware they dont really work on diesels, not throttle body or something. :think:

I heard a Dump Valve was a pretty good investment for a Turbo engine.

Do they not make recirculating ones for diesels then?

have a look at that, kinda explains what they do abit

Got a BOV on my car and all it does is make a noise

So no real point in getting one then?lol

In a petrol turbo engine i.e. 1.8T when you take your foot off the go pedal the turbo stalls. This is because the throttle butterfly closes and due to trapped boost pressure. The pressure stops the turbo spooling. A dump valve releases this trapped pressure so that the turbo can keep on spinning freely. Hey presto no turbo lag when you depress the accelerator again. A diesel doesn't have a throttle butterfly so when you lift off the accelerator the turbo doesn't need a dump valve to keep the turbo spinning. It just continues to spin, albeit slowing down slightly due to slightly less exhaust gas passing through. But the engine is still pulling the same quantity of air through so this keeps the turbo spinning. Adding a dump valve loses this run on effect and slows your turbo down which is the opposite to what you want.

However, with the VNT turbo and the controls system on the VW TDI engine, as you lift off the N75 valve shuts the vanes down on the turbo to prevent overboost. The slight lag you feel when changing gear quickly and subsequent lack of boost is the VNT system pulling the vanes back into full boost position, then you're away again. There's not a lot you can do about that I'm afraid other than changing gear without lifting off.

HTH.

Ok thanks for clearing that up