hi was just wondering if it should have one as std and what would happen if there wasnt any fitted ? only asking as mine has none

 

Yes as std they had one, in the airbox area.
With one missing theory says it will induce a bit of lag, how much it creates depends on many things.
A lot are moved to the cold side, ie between intercooler and the plenum when fitting silicone pipes etc, and then used with a atmospheric dump valve, though of course you can still use a atmo dv on the hot(turbo) side should you wish, though here if using a cone filter it would breathe in some hot air that has already been compressed.
tabetha

 

see my mate has his all blocked off theres no dump valve on any side and and it sound class the chatter from the turbo but ive been told that this isnt good for the car ?

 

A lot of debate about this, the air pulses are getting bounced around all over the place with one end trying to shove the air and the other saying nope I'm staying shut, so the noise you hear is the impeller getting battered by pressure waves.
In short most agree a small amount not really and issue, a large amount of boost is bad, and will shorten the life of the turbo, by how much is like how long is a piece of string!!
It will by it's nature induce some lag, as the pressure waves slow the compressor down, whereas releasing the pressure with a dump valve allows the turbo to stay spinning faster, and so be on boost sooner.
If you want to have both simply use a mondeo front heated windscreen air valve wired via a switch so when open the dv will work as normal from the inlet vacuum signal, when shut(OFF) you will get no vac signal as pipe is effectively blocked by screen valve so you get pressure back up, ie chatter, you won't get the full amount as the pressure will overcome the spring holding the DV shut, so some pressure will come out of here, still get a lot though, to test simply remove vac pipe from DV and plug the pipe with 6mm bolt etc then go for a drive.
tabetha

 

Can anyone confirm the part number of the standard dump valve, and can it be confirmed whether or not it is a Bosch part.

My car never came with a DV, and I'm looking to get everything reverted back to standard.

Please let me know if anyone's selling one. Thanks.

 

i have a bailey black anodised one for sale-fits directly in place of the plastic item-the plastic ones leak,dont hold boost
that bailey one looks standard at a glance until you look closely
pm if intrested

 

Cheers mate. I will bear you in mind, but at the money that's my last resort. I want to keep the car as stock as possible.