S3 Auto: Dedicated transmission cooler

[jagwit]

Thought I would share how I implemented a dedicated auto transmission cooler on my S3.

This came about due to having obtained an alu heavy duty radiator from Silverton Radiators in Knysna - which did not come with the integrated transmission cooler, as per my request.

The original radiator in my car started leaking - again - and I’ve now learnt that any radiator older than 30 years ought to be replaced.

Alu radiator at the bottom, then A/C condenser, then transmission cooler on top. The alu radiator cost me $780 and the small (imported) transmission cooler $200.

tn_20171122_103712_Richtone(HDR).jpg (153.57 KiB) Viewed 1919 times

[baganz.sven@web.de]

Hi Philip,

nice solution like it is very common in today's vehicles.
From my experience you should place it higher because the subcooling area of your AC condensor is in the lower part.
So if you put a transmission cooler in front of the AC condensor you might experience lower cooling performance.

You should try. If it woorks fine like this then you can keep the position.

Best regards
Sven

[jagwit]

From my experience you should place it higher because the subcooling area of your AC condensor is in the lower part.

Could you elaborate on this statement please Sven? I don't understand. It sounds like I might be learning something new.

[baganz.sven@web.de]

Hello Philip,

it is important that the lower part of your AC condenser is not "blocked" by another cooler.
If you put the transmission oil cooler in front of the lower area of your AC condenser you will reduce the
cooling performance of your air condition.

If the cooling air first passes the transmission cooler it will leave it with a higher temperature and this "hot" air will not be able to cool down the coolant of your AC in the same way like air with ambient temperature.
For the air condition especially the lower part of the condenser is important (subcooling area).
So to keep the best performance of your AC you should put the transmission cooler higher so that the lower part of the condenser is exposed to air with ambient temperature (e.g. lower edge of the cooler 10cm above lower edge of the condenser).
Of course it is a little bit "try and error".
In automotive development normally simulations are done to find the optimum position but for "our" cars we can just try.
From my point of view your solution is the best because it is independent from the water temperature of the engine.
Sven