Also begs the question as to why VAG manufacture a bigger intake for this type of engine, if it didnt need it then im sure they wouldnt bother.

Yes but we are talking about making the intake bigger still not the validity of the original part.

Different fuels yes but a they both burn fuel in air to give energy. Diesels generally run with far more air than they need to burn the fuel. This is why increasing the fuelling gives sizable power gains- there is already plenty of air to accomodate the extra fuel. Which begs the question why increase the intake area massively when there is already enough air getting in?

bigger hole allows more air to be drawn in , allowing tuners/remappers to put more fuel in for the extra air and corresponding increase in power also when there is no flap there is probably a ram air effect at higher vehicle speeds . I've not had any problems running without the flap , although i try to steer clear of the large puddles , and it isn't too difficult to undo the clips to twist the coolant hoses IMO , looks better without cable ties pulling the hoses back:)

Just fitted my PD160 intake today, Noticed this restriction and got Mr. Dremel out. Thought it might be something unique to the PD100 but I checked ETOS and the part is the same. It never even occurred to me that it might be for water deflection. :eek:

Not sure if i'm wrong here but after you've fitted the PD160 intake isn't the whole into the airbox the same as before and therefore the restriction is the same?? :confused:

The hole into the airbox is the same diameter as original yeah, but the airbox hole is about the same size as the rest of the pipework on the 160 intake whereas on a standard intake it gets wider at the airbox end to fit in the hole properly.

The hole into the airbox is the same diameter as original yeah, but the airbox hole is about the same size as the rest of the pipework on the 160 intake whereas on a standard intake it gets wider at the airbox end to fit in the hole properly.

Ah! That makes sense now!