nobody has experienced that aerodynamic thing i dont think, i believe its TTs theory

Huh - how do you explain all the failed mechatronics units which the Yanks seem to suffer? Show me a Yank who has a perfectly standard car with a failed mechatronics unit!
Sadly, all the Yanks think its "cool", or dare I use Yankie terminology "sick", to lower their cars, fit those stooopid open fog grilles, and a plethora of other mods - virtually as soon as the car has left the dealers forcourt.
The DSG mechatronics unit is a heat sensitive component. Saying that, Volkswagen will have no doubt spent many hours in the wind tunnel with the smoke wand, bits of string and sticky back plastic - along with considerable hours testing ranging from the Norwegian Arctic to some feckin hot desert somewhere - and deemed that the standard areodynamic profile of the Golf, including the GTI and R32, provide the correct amount of cooling to the correct locations of the cars critical parts, such as the brakes and the DSG. I don't think the average Yank will be able to match VWs test programme, do you?
....I'm not 100% in agreement with you on this either, TT. I don't debate what VW have spent hours testing and developing but I think that the fog grills being 'open' are probably not enough to upset the DSG system as much as I understand you to be saying. For a start, one of them is blanked off just behind the open honeycombe, and the other is partially blocked off.
Oh boy. Its a shame the forum crashed a while back!

Look, in the original "pre-production" models released to the press, the GTI had "open" fog grilles - on both sides, like this:

However, after a very small number of the initial production GTIs which were released with those grilles, all future production GTIs had fully closed grilles. So why, then, did VW feel the need to modify a part during a production run?

Cost - not really, asthetics - nope - so it must only be down to the performance of the individual part.

Even on the higher output Ed30/Pirelli models - and therefore hotter running - VW still use the fully closed grilles:


So, by using your logic RR that these "open" grilles don't upset the airflow, particularly to the DSG - why then did VW change them to fully closed versions.

And you are wrong about these fully "open" grilles. Yes, agreed that the one on the right is actually blocked off (however, most owners, particularly the yanks will dremel off the rear cover, and merely freeze solid their screen wash bottle in the winter!), but the right one is most definately fully open. This was officially designed by VW for a "tropical climate" market - specifically Mexico and South Africa, and its purpose is to duct air to an additional large radiator behind the left fog light. However, even with the supposed substantial additional cooling from this additional radiator (which is about a third of the size of the main rad) - this "tropical climate" spec was never fitted to any cars (in South Africa, Mexico, or any other "hot" locations, such as Dubai or Arizona), because again, the supposed benefits from this additional radiator were either (a) not worth while, or (b) actually detracted from the cooling of other items. Now, unless anyone here actually works in the R&D at Wolfsburg, we will never know the real answer.

Now, going back to aerodynamics, you really do need to get a handle on the basics, and sadly, you don't appear to have any real grasp on the basic fundamentals of aerodynamics.

But I do understand that you are describing a downside of a combination of several aftermarket components.
OK.

Weren't the fog vents open originally by VW to gain extra cooling to the DSG but then found not to be needed and subsequently dropped to streamline the economics of production between DSG and non-DSG cars?
Nope, they were designed to provide additional cooling primarilly for the
engine coolant - and for non-DSG cars too. The internal ducting for these open grilles actually angles away from the DSG, in an orienation manner as though it was venting out of the side of the car. The simple fact that the wheel arch liner is no longer available with the exit louvres for this rad must show how ineffective the whole system was, and maybe how it was starving the actual DSG of air?
OK, it could losely be argued that the DSG
might also benefit, soley on the grounds that the DSG oil (along with the engine oil, and the turbocharger) also take a feed from the engine coolant. However, their cooling benefit is of considerably less when compared to the engines own requirement - which would also explain why this is not used in hot climes.

My Mechatronics Module failed at about 6k miles and well before I changed to 'open' fog grilles. I'm not at 52k miles and have had 'open' vents for at least 25,000 miles without any problems.
And . . . there is no logic to that statment. You can not "prove a negative". It uses the same misguided reasoning such as: If Fred Smith was to drive along UK motorways for a whole year at a constant speed of 120mph, and not get nicked - then 120mph is legal for a UK motorway!

Negative logic is very bad logic - which probably explains why politicians use it so much. Unfortunately, negative logic proves Jack Schit! Sorry to be so blunt!
