TT, tell more if you can. AXX ist listed so I may conclude they fitted some AXX with it.
But that's not the point. Many mapped TFSIs with K04 run more power than the
Mk.VI R from factory. As the picture proves at least 'some' Golf R do come with it.
That's why I say that retrofitting this on higher powered TFSIs will provide an
advantage. They will run cooler. A bad thing?
You are confusing modified over standard.
To specifically discuss standard - this issue of the additional coolant rad was raised many moons ago (can't remember if it was on this forum or the other GTI forum). The crux of the issue was that whilst ETKA shows that this additional rad
may be fitted - our extensive research proved that it never actually had been fitted. This included cars which were official exports to both 'hot countries' AND 'super- hot countries' (as listed in the ETKA pr detail). We had forum members from places like Dubai, South Africa, Australia, Greece who didn't have this rad - and we also sourced info from the yankie GolfMkV.com forums for others in Mexico, California and the likes - again, no one had this additional rad fitted.
So, if a standard GTI which is being spanked in the deserts of Dubai does not have any cooling probs on the standard radiator - then I'm pretty confident that a moderately tuned GTI used here in Blighty or northern Europe will still be perfectly OK on the standard coolant rad. A really big clue to indicate any overheating or lack of efficiency of the standard cooling system will be shown by either a rising temperature gauge, or more probably, the cooling fans working at 100% duty when they normally wouldn't (save for those common-ish problems of faulty cooling fans).
It is important to understand that 'air' is generally a fixed 'volume'. OK, there are differences in ambient temperatures and pressures changing the density - but that is generally very small changes. The front of the GTI (just like any car) is designed to use this specific volume of air in a very determined manner. That means feeding air to the engine air intake, feeding air to the cooling system and air conditioning rads, feeding cool air to the intercooler, feeding air to the front brakes, and feeding air underneath the vehicle to cool the bottom of the engine and transmission. This is all achieved via CFD modelling and wind tunnel testing to create specific high pressure areas on the front of the car, which will then feed or channel the air in a specific direction and/or towards a specific component.
If you then modify that airflow - you will be diverting air away from one component to another. The most <cough> popular <cough> modification on the Mk5 is to fit 'open' fog lamp grilles - by doing so, you will actually take air away from both the front brakes, and to a certain extent, the lower centre grille area - which feeds the intercooler, air con and normal rad.
Front airflow is further referenced in (I think) the new Ford Fiesta advert - something along the lines of CLOSING the active grilles at speed to improve the airflow !
Like I said, all car companies spend millions on computer modeling, CFD and wind tunnels to achieve the optimum airflow - especially on the front of a vehicle (granted, they often loose patience when it comes to the rear end airflow!)
