Cooling a Supercharged S4
#31
Addict
Rennlist Member
Rennlist Member
Definitely check/change the "thermostat inner seal" I believe it's part 92810616300. These are nearly always overlooked and often so encrusted in buildup that it looks like part of the casting. If it's not functioning, some water will bypass the radiator as I understand it. It seals the secondary disc valve then the thermo is open (hot)
http://en.wikipedia.org/wiki/Wax_the...thermostat.jpg
-Joel.
http://en.wikipedia.org/wiki/Wax_the...thermostat.jpg
-Joel.
#32
Rennlist Member
Do not run the 75/25 mix without the Redline water wetter or an appropriate anti corrosion chemical package of some suitable kind. Good coolants can be diluted 66/33 without additional chemicals [as I know] but if you do change them out every two years.
I understand the 928 Motorsports radiator has cooling coils in both end tanks. You can probably forget the check on the leaves/crap on the front side of the radiator as it is relatively new.
Rgds
Fred
I understand the 928 Motorsports radiator has cooling coils in both end tanks. You can probably forget the check on the leaves/crap on the front side of the radiator as it is relatively new.
Rgds
Fred
#33
Developer
Like FredR's suggestions a lot. They mirror my own.
Keep in mind the 928 barely cools well enough in equatorial/hot climates even without a supercharger. In stock trim, look at the threads about overheating, fans running at stop lights, and radiators exchanges in the hopes of driving the temp down and you know its edgy already.
Fred's right - you must use every tool available to you.
It has little to do with the supercharger other than more HP means more fuel means more heat. That exacerbates a problem the 928 already has in hot climates.
BUT: it can be handled and solved. Many of us have done it. And SC cars in other climates that are cooler have no issues at all.
Keep in mind the 928 barely cools well enough in equatorial/hot climates even without a supercharger. In stock trim, look at the threads about overheating, fans running at stop lights, and radiators exchanges in the hopes of driving the temp down and you know its edgy already.
Fred's right - you must use every tool available to you.
- The right mix of antifreeze - as much water as possible
- water wetter
- clean, unplugged radiators
- shrouds on all sides of the radiator in place
- good fans
- fans wired to turn on earlier or just run them all the time
It has little to do with the supercharger other than more HP means more fuel means more heat. That exacerbates a problem the 928 already has in hot climates.
BUT: it can be handled and solved. Many of us have done it. And SC cars in other climates that are cooler have no issues at all.
#35
Developer
Electronic fan controllers.
These work very well and they help. Then you can get a jump on the heat rise by turning the fans on sooner. Cheaper than a failed (and overly-complicated)
Porsche 928 fan controller unit.
I sell them cheap, but they are available everywhere:
http://www.928motorsports.com/parts/...ler_switch.php
These work very well and they help. Then you can get a jump on the heat rise by turning the fans on sooner. Cheaper than a failed (and overly-complicated)
Porsche 928 fan controller unit.
I sell them cheap, but they are available everywhere:
http://www.928motorsports.com/parts/...ler_switch.php
#36
Developer
I understand the 928 Motorsports radiator has cooling coils in both end tanks. You can probably forget the check on the leaves/crap on the front side of the radiator as it is relatively new.
Here: http://www.928motorsports.com/parts/alumradiator.php
#37
Rennlist Member
The one I saw over here had coolers on both sides if my memory serves me correctly. Assumed you probably did a std spec- clearly not the case. It looked a pretty nice piece of kit.
As a matter of interest what thread size do the cooler connections come with? Presumably it will be something like M18 x 1.5. I am hoping to do some plumbing modifications on mine shortly.
Rgds
Fred
#38
Nordschleife Master
Often overlooked by inexperienced workshops or owners.
The coolant bridge is relatively easy to remove - on a stock S4 it can be done without removing the intake manifold - although I'm not sure whether your supercharger setup may interfere with that.
#39
Thanks Carl, I will take a look behind the driver's side (RHD) wheel well tomorrow. Forgive my ignorance, but how do I go about disconnecting the SC heat exchanger? Are the hoses full of water? I'd like to have a go at this job myself but some advice would be appreciated!
#40
Rennlist Member
Good luck,
Dave
#41
Nordschleife Master
My views:
- It helps to make sure that the engine is in otherwise good condition before starting to debug the cooling system.
- The additional heat exchangers should be moved to fenders and away from the front of the radiator. There's plenty of room in the fenders.
- You want to plumb the end tank oil cooler in series with an external oil cooler.
- Belly pans need to be on for the engine compartment to cool properly. Makes a big difference.
- Thermostats need to be working.
- It often helps to clean the radiator.
- Anything that one can do to seal the duct from bumper cover opening to the radiator such that all the air has to flow thru the radiator will help.
- It helps to know the actual temperatures of oil and coolant when diagnosing cooling issues.
- It helps to make sure that the engine is in otherwise good condition before starting to debug the cooling system.
- The additional heat exchangers should be moved to fenders and away from the front of the radiator. There's plenty of room in the fenders.
- You want to plumb the end tank oil cooler in series with an external oil cooler.
- Belly pans need to be on for the engine compartment to cool properly. Makes a big difference.
- Thermostats need to be working.
- It often helps to clean the radiator.
- Anything that one can do to seal the duct from bumper cover opening to the radiator such that all the air has to flow thru the radiator will help.
- It helps to know the actual temperatures of oil and coolant when diagnosing cooling issues.
#42
Electron Wrangler
Lifetime Rennlist
Member
Lifetime Rennlist
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Alan
#43
Rennlist Member
I think the biggest impact of most superchargers is the simple physical one - by limiting the area available in the middle of the back of the radiator it may restrict airflow somewhat - but mainly it limits you from installing dual puller fans with good flow through shrouding - the most effective fan configuration.
Alan
Alan
Dave
#44
I think the biggest impact of most superchargers is the simple physical one - by limiting the area available in the middle of the back of the radiator it may restrict airflow somewhat - but mainly it limits you from installing dual puller fans with good flow through shrouding - the most effective fan configuration.
Alan
Alan