Question about secondary intercooler/radiator

[AudiC7Owners]

I was browsing these diagrams in prep for installing my Merc Racing heat exchanger, and it got me curious. The small core on the drivers side for the 3.0T... It's it a secondary intercooler/heat exchanger? Or is it a secondary radiator?

Secondly, on high horsepower cars, is this something that would help if it were upgraded?

Lastly, is this standard on all 3.0T's? How about 4.0TT's?

Part in question is #1 in the diagrams




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[OlyS6]

I can vouch that it is present on the 4.0T as well (at least the S6 and S7), although I have to admit I'm not certain of it's function, and I've not seen anyone look to upgrade it.

[AudiC7Owners]

I can vouch that it is present on the 4.0T as well (at least the S6 and S7), although I have to admit I'm not certain of it's function, and I've not seen anyone look to upgrade it.

Is it also on the drivers side?


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[gk1]

The self study guide for the 4.0T doesn't show the auxiliary cooler as part of the charge air cooling system when they are describing the charge air cooling system. It is specifically named "auxiliary coolant cooler" in the diagrams which would also lean me toward it not being for charge air cooling just a secondary radiator otherwise I'd think it would have "...for charge air cooling" at the end of its name.
However, from the image they show the "charge air cooling pump V188" directly connected to the auxiliary cooler so I don't see how it would not be a part of the charge air cooling system.
Some places list it as "low temperature coolant cooler" if that makes sense...
Following the diagram flow of the charge air cooling coolant it does appear hot coolant flows from the charge air cooler in the V to the front charge air cooler. Then "cooled" coolant flows out of the front charge air cooler to the charge air cooling pump then back to the V but with a "T" that looks like it would go to the auxiliary cooler that they do not show in the diagram....hopefully someone who has examined it thoroughly will have more insight.
Sorry if that is not much help....

[OlyS6]

Is it also on the drivers side?


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Yes, same location, and with the same plastic funnel (part 7 in the diagram) leading to it.

[Dasquade]

I would need to try look it up aswell like i tried in the past, with not much succes :p...but since afaik we have a non divorced cooling system i supppse it is just an additional radiator. Since coolant finds its way through the system and T, any extra coolers will help i suppose. I remember reading an old topic regarding coolant volume versus cooling surface (it aint always good to have more coolant in the system, yes it takes longer to heat up but takes longer to cool all volume back down again).
Like i posted earlier, afaik they also over an extra additional cooler unit for hot countries on the passengiers side and curious if we could integrate that one (i have after market tripple pass one so i could exit into additional left cooler).

[wwhan]

The secondary radiator looks like part of the after run cooling circuit feeding the "V51 After-Run Coolant Pump", then the ATF heat exchanger, when engine is off.

The read circle and arrow is the coolant reservoir location where engine coolant & charge coolant are common.

[gk1]

The secondary radiator looks like part of the after run cooling circuit feeding the "V51 After-Run Coolant Pump", then the ATF heat exchanger, when engine is off.

The read circle and arrow is the coolant reservoir location where engine coolant & charge coolant are common.

That is interesting and makes sense, just doesn't match the picture on page 52 where they show the charge air cooling pump V188 connected to the auxiliary radiator. (Might just be bad Audi pictures or wrong text...wouldn't be the first time.) The V188 pump connected to the aux radiator makes sense for the A8/S8 as the schematic for those on page 45 clearly shows V188 connected to an aux radiator.