Removed Auxiliary Radiators

[nene]

I finally got around to removing the auxiliary radiators after the Sportec intercooler upgrade.
I had left them in place as I ran out of time, and was happy to get my hands on the car for some service, and do the removal of these.

Went to Autozone to get some 5/8 hose to finish up the connection once the radiators were removed.
I hate the default clamps that come with the hoses. Don't get me wrong, they are great to keep things in place, but a pain to remove, even when you have the right tool.

Needless to say, I was able to take the beast for a spirited drive and logged the coolant temperature, as seen in the image below. So far looks good I think, as I did not seem much of a change in temperature, based on the gauge read out. I don't have a log for coolant temperature readings before the change.


http://home.comcast.net/~nelson.paiva/img/Temperature.jpg


FYI:
I have original auxiliary radiators, intercoolers, and shrouds. If anyone is interested in the parts, send me a reasonable offer.

[hahnmgh63]

I removed mine around 3yrs ago when I pulled the engine. Keep in mind that most markets never had the Aux radiators. It was standard in N. America but optional in most other markets so the original idea didn't include them. I've never felt that my car was getting too warm but I do live in Washington state, temperate climate, and don't do much stop & go. We do get the temp into the low 90's in the summer and I've still had no problems there.

[lswing]

Haven't noticed any temp changes since we removed mine a few years ago. Needle has always stayed in place, but I've heard that it takes a good temp swing to move the needle?

Had a month of 90 degree temps and it was fine. It's got to allow more air through and certainly less heat soak around the IC's, that along with water methanol has allowed full power through the summer.

[SA RS6]

im not sure this would be a good idea for me here in texas. 100+ in the summer, i need to get vents in my hood stat. already did the sportec mod and that helped, but on spirited runs she gets a little warm. but it's the oil temps that climb up not the coolant.

[G2]

Cool info: That's 201-210F. I'd wonder if it was logged when parked or driving? Ambient temp?

-- must be with OE spec t-stat.

From what I see that range is a typical hot reading in most Audi's when parked in our area. The fans normally kick on around 210F (ours are PWM) for the first stage.

185-190F is where my car runs cruising on the freeway, with both aux. radiators in place. I use Amsoil Coolant Boost (like Redline WaterWetter) that should help some. It certainly helps with a faster warmup (intended), which was obvious w/o testing.

Oil temp this time of year is 175-190F. I've noticed that hotter engine coolant will often cause the oil temps to increase, including transmissions.

More power and less cooling ability that factory supplied, is an interesting proposition... for a 11 yr old car. Be interesting to get more data together.

[nene]

When I started the logging it was parked, and engine had been running for about 5 minutes.
Most of the logging however was when driving. Mostly city type driving, with a few stop lights and some spirited driving.
No freeway though on this run.

Exterior temperature was around 70-72 F.

Thanks for the updates fellas.

[mik15]

same here where in the summer it gets super hot(even 120F), the coolant temperature on the cluster never goes beyond 90, however vcds says it is at around 99-100C, which is high i think considering that the T-stat is 82C. On my BMW the coolant rarely goes over 93C and when it does i am stuck in traffic, otherwise on the highway it sits around 87-90C, is there anyway to make the RS run cooler?

Obviously i do have the "engine cooling system for super hot country" (8Z9 option) . The extra radiators only came as standard on the Plus version, US and hot climate countries.

[lswing]

I probably would have left mine for the reasons mentioned had they not been so corroded and leaking. I think there's some performance benefit with them gone, but worry about the warmer weather.

The turbos are going to heat up the oil. Amazing how much cooler my brothers V10 supercharged M5 oil temps are.

If I end up in warmer weather than the NW, might put them back in. Also looking at upgrading the trans fluid and oil cooler radiators up front. Can have custom work done for ~$1,500 installed.

I'll grab some logs in a month or two when it warms up.

[nene]

I meant to ask this earlier, since some cars apparently did not come with these in other countries, but is there a part number for the hoses that connect the tubes, where normally the auxiliary radiators would be?
I had to get some other hoses from local Autozone, and that worked, but I figure there must be a better part to replace what I did.

I checked the US manual for the RS6, and can't find those parts, as I would not expect it would appear.