Removed Aux rad...big improvement

[andyg plym]

Recently I removed the auxilary rad as it was worn out with an F. I joined the hoses together with a hacksawed piece of pipe (from my boys mini scooter ) and made sure there were no kinks in the hoses,then bled the system.
This is a highly reccomended mod,the car stays much,much cooler.
I used to have the temp needle just under 90 (half way) even on the motorway,now it tends to stay at a quarter of the way up.
Easy mod,you know it makes sense!!

[k.alle]

Well, i always thought that just below 90 was the optimum temperature to have.
Are you seeing like 70 degrees now?
Seems a bit low to me, but i have been wrong before.

[mcandmar]

You shouldn't join the hoses together as your bypassing the main radiator, you need to block them up instead.

[andyg plym]

...

Really? Ive seen this done on s2's before and my mates Rs2. Hmm looks like i may have to invest in some hose plugs then?

[S2central.net]

Linking the auxrad pipes means water bypasses the main radiator.

Block them up you dime bar

Paul

[andyg plym]

oh geoffery

[Rusty]

You don't want it to run too cold otherwise the ECU can run in cold start mode. Under 80 isn't good from what I've been told.

[Acidburn]

Have you noticed if sitting in traffic the fan coming in more often?

[andyg plym]

nope...all seems fine.

[K Simmonds]

Have you ever changed the thermostat?? As like the other guy's have mention optimum running temperature is about 90 degree's centigrade. If you not getting up to running temperature on the motorway your thermostat may be stuck open.

[Jamo]

Linking the auxrad pipes means water bypasses the main radiator.

Block them up you dime bar

Paul

I've lost count the amount of times i've told people NOT to do this!

[andyg plym]

well its all sorted now,2x bungs in the hoses( 1 old thermo switch which is tailer made and 1 old intercooler mounting bolt)

bodgery at its best in the shister weather today

[Dirtylouie]

Could you guys pls explain the benefit of not having an aux rad?
AFAIK the less radiating area (surface) you have - the lower the heat exchage ratio goes. Same thing with loosing about 1 liter of coolant, when extracting aux rad. Seems pretty dangerous to me, specially when you have about 40 celcius 50cm above the tarmac.

I am right now thinking about having AAN radiator in front, along with AAN intake. seems to be a tough conversion task.

[S2central.net]

Well the benefits are as follows -

- Less weight in front of the engine
- Greater access to the front of engine for maintenance
- Increased airflow over the engine when moving

The disadvantage is that the electrical fan cuts in more often when sitting in traffic cos of the lower heat exchange capability, BUT when moving I can absolutely tell you the auxrad has no beneficial effect on the cooling performance. If anything I have seen water temps drop from 90 on a motorway run to 87-88 degrees with the auxrad removed.

Plenty of folk run trackdays without the auxrad and have no problems. IMO, Audi over-engineered the cooling with that aux rad - it is perhaps advantageous on a hot day stuck in traffic, but not to the point that the main radiator (with automatic fan assistance) cannot cope on its own.

Paul

[Error404]

don't forget cars are built for all climates and conditions. perhaps in the Saudi desert on a really hot day stuck in traffic you might need the aux rad to prevent overheating, but i think we're probably safe in northern Europe