Standard intercooler airflow


Active Member
Dec 6, 2007
Has anyone tried to increase the airflow into the standard intercooler to make it flow better? Im thinking of experimenting with opening up the grill infront of the intercooler on the Tolly

Already put on a good make tuning box and cut the cat out, egr is on the list next and if it ever arrives ive got a airbox that im going to modify to flow better too :) the change in power on the car from standard is phemominal already :)


Active Member
Sep 17, 2008
You could put in a vent in the wheel arch behind the intercooler. Audi tt's have them standard in the wheel arch.

And/or take out the fog light so more air gets to the front.


Active Member
Oct 18, 2006
The intercooler reduces the temperature of the air compressed by the turbocharger (which is hot). Colder air is denser and as such has more oxygen available for combustion, compared to the same volume of hot gas.

The more you comporess the air coming into the engine (more boost) the hotter it will get, so the intercooler needs to be bigger to maintain good air temperatures into the engine.


Andrewcupra TDI

Resident Desk Jockey
Apr 30, 2008
in the mountains ( Wales )
ye , i couldnt really grasp how air made its way into the IC , i knew air would cool it , hence FMIC would get colder air being upfront
but couldnt understand how it gets there

as i imagine the air drawn in from the air filter , and then what the turbo makes ??



Catch that diesel!
Mar 17, 2006
North Kent
Um. Briefly:
Air path to the combustion chamber:
Air intake. behind the headlight. Gets coolish cleanish air from the front of the car.
goes to
Air filter. Screens out dust dirt gravel flies badgers etc
goes to
Turbocharger compressor. Compresses the air, get more oxygen into the same volume of gas. Heats the air too (think about what happens to the bottom of a bicycle tyre pump when you inflate a tyre, or feel a footpump after topping up a tyre)

All the air pipes from here to the engine have to contain high-pressure gas.

Next is the intercooler. This is just another radiator, a heat exchanger like the ones for the engine coolant, cabin air heater and so on. In this case the hot inlet air inside it is cooled by air drawn over it from the outside. The main advantage of the FMIC is that it is larger and so gives better cooling.

From there, the air goes to the inlet manifold. Just before the manifold will be the EGR and anti-shudder valve on a diesel, or the throttle body (with EGR if it is applied) on a petrol engine.

And then into the engine.

Gas flow diagram is at the bottom of this picture wot I drew myself ages ago to describe how the vac pipes interconnect on a TDI 110. Hope this helps

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