Auxiliary Radiator Delete

[sonny]

Not sure you'll gain much there. The main radiator is the same circuit as the aux so putting one infront of the other doesn't feel right.

This is what I was thinking to, if the air flow is goof enough through the aux rad then maybe worth it.

[ROY]

Wow the painted inlet and them silicone hoses look Awsome
Really sets the engine bay off
Nice work

[P_G]

Not sure you'll gain much there. The main radiator is the same circuit as the aux so putting one infront of the other doesn't feel right.

That and whatever airflow you are gettting through the aux. rad being placed there you are taking away from the area of the main rad. it obscures which as ads says is in series so minimal if not zero gain?

[00-Schneider]

At higher speeds on the German Autobahn, we were facing temperature problems without the aux radiator. Putting a cooler in front of another is technically allright. I don´t have any problems with temperature now.

Furthermore, Audi saw reasons to place in total 3 water cooler in the RS4. It´s also a matter of total fluid capaticity. Just deinstalling a cooler isn´t the right way.

Regarding the catch can - we also found out, that there´s no gain at all. What you can do against this well known problem is a special way of cleaning the inlet manifold and hereby also the inlet valves. This system is called BEDI and unfortunately not available in the States i think. By using BEDI, you infill a special cleaner into the car´s injection system whilst it´s running.

On the dyno, my car had 367 PS before BEDI and 389 PS afterwards.

My total engine mods are -> Software, Supersprint downpipes (no pre-cats, 100 cpi main cats), airfilter (just the mat, but no K&N oily stuff - i used a Sandtler SC which is olifree), Supersprint middle section (real silencer, no x- or h-pipe) and the ramairbox as shown above.

Will roll the car soon...expect 420-430 PS - wait and see (and hope)

So long,

Sebastian

[sar]

At higher speeds on the German Autobahn, we were facing temperature problems without the aux radiator. Putting a cooler in front of another is technically allright. I don´t have any problems with temperature now.

Furthermore, Audi saw reasons to place in total 3 water cooler in the RS4. It´s also a matter of total fluid capaticity. Just deinstalling a cooler isn´t the right way.

Regarding the catch can - we also found out, that there´s no gain at all. What you can do against this well known problem is a special way of cleaning the inlet manifold and hereby also the inlet valves. This system is called BEDI and unfortunately not available in the States i think. By using BEDI, you infill a special cleaner into the car´s injection system whilst it´s running.

On the dyno, my car had 367 PS before BEDI and 389 PS afterwards.

My total engine mods are -> Software, Supersprint downpipes (no pre-cats, 100 cpi main cats), airfilter (just the mat, but no K&N oily stuff - i used a Sandtler SC which is olifree), Supersprint middle section (real silencer, no x- or h-pipe) and the ramairbox as shown above.

Will roll the car soon...expect 420-430 PS - wait and see (and hope)

So long,

Sebastian

i have just returned from my euro tour and i seen a fair bit of autobahn action in temps of over 30 degrees.
in the south of france the temps got to 42 degrees all-tough i wasn't going quite as quick!.
i have the cold air feed/aux rad delete and my temps were ok, the needle never went above half way just the same as pre aux rad delete...?.

[00-Schneider]

@ sar - your OEM gauge is worth nearly nothing. Audi balanced this gauge to be a cheater - equal if your engine has 85 oder 110 degrees - it´s still in the middle on 90.

As long as your drive, even 42 degrees are ok, but as often as we´re able to drive highspeed, we´re also into deep traffic-jam...and this puts enormeous stress on the head gaskets.

I´ll keep my solution - especially because i also visit the Nurburgring very often (it´s just 30 minutes away from my house).

[sar]

yer im sure i remember reading somewhere on the net about audi fudging the water temps gauge on an audi 80 engine or something.
supposedly customers complaining about the gauge always reading hot, so audi fixed it by restricting the water temps gauge from going over half way!.
did you log the temps with Vagcom with and without the auxrad?, care to share some data? say high speed runs with and without out and sat in traffic with and without, outside air temps ect...

i went to the ring aswell , i might have driven past your house. i only saw two other rs4's at the ring a yellow b7 on german plates i think and a black b5 also german i think.

[adsgreen]

Alternatively, I wonder if you could bin the thermostat and pump and replace with a electric pump...

[00-Schneider]

@ adsgreen - the waterpump itself is strong enough. The RS4 needs radiator surface to cool down whilst the car is stucking into traffic jam or similar situation. Overheating is an issue on the RS4.

@ sar - yes, i logged the temps by VAG com. A friend removed the aux rad and by comparison, his water temp went really wrong. My RS4 is a black estate. Here are some pics.






Sorry for OT.

[andre3k]

@ adsgreen - the waterpump itself is strong enough. The RS4 needs radiator surface to cool down whilst the car is stucking into traffic jam or similar situation. Overheating is an issue on the RS4.

@ sar - yes, i logged the temps by VAG com. A friend removed the aux rad and by comparison, his water temp went really wrong. My RS4 is a black estate. Here are some pics.






Sorry for OT.

What tail lights are you running bud?

[00-Schneider]

They had been "painted" by a company called tail-light-specialists - i tried LED ones, but they look very Chinese and don´t match to a premium car at all...furthermore, my on-board-diagnosis pointed out failures although is used the delivered ballasts.

OEM is always best - that´s why i kept the original tail lights and added some Darth Vader-paint

[adsgreen]

@ adsgreen - the waterpump itself is strong enough. The RS4 needs radiator surface to cool down whilst the car is stucking into traffic jam or similar situation. Overheating is an issue on the RS4.
Sorry for OT.

Hmm - not heard that the RS4 is bad for overheating. I've always thought that radiator surface area wasn't that effective without airflow over it. As such the idle temps are going to be dependant on the engine fan. I wonder if your friends car had other problems?

Leccy waterpump just means you can control the temperature of the engine very precisely irrespective of engine speed. So when you are sitting on the authbahn it spins slowly and when you slow down to a stop it would speed up the coolant to take account of the lack of airflow.

[PetrolDave]

[quote="adsgreen"I've always thought that radiator surface area wasn't that effective without airflow over it. As such the idle temps are going to be dependant on the engine fan.[/quote]
+1

Surface area is only a minor factor in how much cooling a radiator provides, airflow through the radiator has a much bigger effect. So putting the aux rad in front of the main rad will just result in blowing/sucking hot air onto that section of the main rad and reduce it's effectiveness.

[BlingBling]

Surface area is only a minor factor in how much cooling a radiator provides,

Wrong on so many accounts. Radiators need a high ratio of surface area to fluid volume to provide efficient cooling. To dismiss surface area as a minor aspect when it comes to cooling is poor. Air flow through the radiator is important but so is the surface area. It is pointless having a good flow is there is insufficient area to quickly dissipate the heat.

[00-Schneider]

Surface area is only a minor factor in how much cooling a radiator provides,

Wrong so many accounts. Radiators need a high ratio of surface area to fluid volume to provide efficient cooling. To dismiss surface area as a minor aspect when it comes to cooling is poor. Air flow through the radiator is important but so is the surface area. It is pointless having a good flow is there is insufficient area to quickly dissipate the heat.

This is totally correct and reflects the experiences we made. If you pump hot water with an enormeous speed through a small cooler, the fluid hasn´t enough time to get rid of it´s temperature. Surface is really important - especially on the RS4. Audi installed a huge engine in a rather small place. The B7 platform wasn´t developed to take a V8. When you watch the engine area in the car, it´s really impressing how they managed that. That´s why Audi installed 3 water cooler - and that´s why i decided to keep all of them.

Cheers,

Sebastian