pick an RS4 oil cooler or the RS4 intercoolers if you were doing K04's and why? Thanks.

 

I'd go with the oil cooler and do the intercoolers when I had the green.

 

driving even if they get heat soaked pretty quick. The RS4s are finned for high speed long distance runs, but better resistance to heat soak because of the larger core. The pressure drop advantage of RS4s is not hugely significant.

 

The intercoolers are a no brainer to get the full advantage of the K04s and increased boost pressures.

From what I have heard, Audi Sport set up the race cars to run at 100 degrees C (212 F), but no higher. This allows the oil to get rid of water, but keeps the engine at a proper operating temp without breaking down the oil.

Remember, on Audi turbos there are oil jets that cool the pistons, meaning that the oil is not only used as a lubricant, but also as "coolant". The stock 2.7T has a oil to water heater exchanger, but this has only so much capactiy. When you put in K04s and up the boost, this means more heat in the pistons, and therefore increased oil temps. According to the RS4 service training manual,"In order to maintain engine oil temperatures within the range specified for the engine under all operating conditions, an additional oil cooler is fitted below the main cooler." Do also note that the RS4 engine has a larger oil pump for more flow. The manual also lists the maximum allowed oil temperature as being 135 C.

In the real world, you can't drive a car in the US like you can with an RS4 on the Autobahn, so it is unlikely that you will build the kind of oil temps that would require the oil cooler, *unless you track the car*.

So, I would say definitely do the RS4 intercoolers if you want all of the performance from those K04s. If you are going to run the car hard, get the oil cooler as well for the longevity of the engine.

Steve

 

Oil cooler

 

Good info.

 

I'm interested to see stuff on Duh's FMICs, but they are pretty pricey. AWE's stuff should be interesting as well, especially the water/air unit.

-st

 

only real advantage is marginally less heat soak power loss. The K04s should give me enough real world compensation via power upgrade, plus I'm expecting more lag from the bigger wheel spool up time that the pressure drop issues should be relatively inconsequential. I plan to run AMS and a 5 Bar FPR with downpipes with a drilled air box as a Stage 2+ until tuners get the fuelling part of the equation with ECM tweaks down pat. Won't do downpipes until my warranty is up in about a year. That will be phase 1 of a step up upgrade plan over time to properly evaluate the real world benefits of each step.

 

Cool - that should make for some fun work. Are you doing the turbo swap yourself?

 

at the dealer when the clutch/turbos go in. Probably still less than 2 years away on the S4 for all the steps to reach completion. By '05, it'll be done in time to trade up for a B6 RS4.