Front Grills, do they raise temps?

[iborguk]

25 minutes ago, Paul P said:

Rise tinted goggles.  
 

“ leave it guv’nor - he’s had enough “ 

At least you didn't go with "I could be so good for you".

[iborguk]

Actually, maybe that should be the tag line for the front grills...vague attempt to drag it back on topic...

[Paul P]

I could design the grills.  Cut the grills. Paint the grills. Fit the Grills sing the theme tune.  

Edited May 4, 2023 by Paul P

[Menoporsche]

18 minutes ago, Paul P said:

could design the grills.  Cut the grills

As long as you use a Rula. 

[Paul P]

3 minutes ago, Menoporsche said:

As long as you use a Rula. 

Have you got one you could lenska to me ? 
 

Rock follies.  
 

Now there’s a teenage duvet issue.  

[iborguk]

Galloway with you…

[½cwt]

They must cause an airflow blockage (and more turbulent air which is less efficient at cooling), pure physics, however if the ducting is flowing more air than required to start with then a small %age blockage will make no difference.  Plus as note above the condensers sit in front of the rads causing a significant blockage and passing warmer air on to the rads.  These car work in California, so must have a good cooling capacity, not to mention 20 odd litres of coolant compared to most other 'conventional' layout cars having 5 to 8 litres.

Haven't noticed any problems with the DIY grilles on my 986S.

Edited May 4, 2023 by ½cwt

[moospeed]

I was initially more concerned with WTF Porsche were thinking in fitting a centre section that appears to be the most un-aerodynamic design possible.

Then having thought about it more I realised that once the pocket of air pressure is full / maxxed out then maybe it helps somehow to flow the air somewhere or break it up for less resistance.  I don't know, intuitively it looks wrong but they must know what they're up to I guess.

I've been tempted to put grille over that section for looks alone, though as I haven't put my condenser grilles back on since the service I doubt I'll bother.  I prefer the look of them without.  The wife's Qashqai doesn't have grille in front of the rad and intercooler and that's on one of the biggest selling cars out there and people don't fit grilles to those.  It's under the number plate so the "hole" isn't massively higher than those on the Box. 

[iborguk]

 

[Menoporsche]

I would say they cause a lot less cooling problems than the leaves and stones they prevent.

[½cwt]

37 minutes ago, moospeed said:

I was initially more concerned with WTF Porsche were thinking in fitting a centre section that appears to be the most un-aerodynamic design possible.

Then having thought about it more I realised that once the pocket of air pressure is full / maxxed out then maybe it helps somehow to flow the air somewhere or break it up for less resistance.  I don't know, intuitively it looks wrong but they must know what they're up to I guess.

I've been tempted to put grille over that section for looks alone, though as I haven't put my condenser grilles back on since the service I doubt I'll bother.  I prefer the look of them without.  The wife's Qashqai doesn't have grille in front of the rad and intercooler and that's on one of the biggest selling cars out there and people don't fit grilles to those.  It's under the number plate so the "hole" isn't massively higher than those on the Box. 

At risk of getting into the black art of aero dynamics, there is a lower pressure area under the car where the air has been allowed to run freely so there will be a negative pressure gradient from the front of the bumper moulding to the underside of the car as well as the statis pressure where the car is forcing its way through the air.  This is however much more complicated with the two outside ducts int eh bumper and the wheel arches and all the flow interactions and stalled, turbulent air in those areas.

[mrbikerdood]

I bought some black mesh from ebay,took my 981s to Dovehouse in Rushton in Northants and got them to take the bumper off and fit the mesh behind the grills - they've been on about 6yrs now - temp never raised or ever had an issue & cost me only £80 for labour, (bumper has parking sensors so didn't fancy doing it myself)

Edited May 17, 2023 by mrbikerdood

[carl s]

Some pretty strong views on the topic of whether grills cause overheating from Jack Raby:

 

[Menoporsche]

Apparently Jake Raby was doing online diagnostic of any 9x6 engine failure as IMS related, someone mentioned here. Seems he trades on his reputation a lot. 

[Carmine]

Interesting video but his conclusion about grills causing overheating is not particularly scientific. There’s no apparent consideration of the age and health of the components in the cooling system.

He also admits that fitting the grills at some stage in the cars life and leaving any debris already there in place is what often happens.

Putting thermocouples on the radiator inlet and outlet and monitoring temperatures in real world use on the same car with and without grills would be a scientific test.

[BrianJ]

I've had Zunsports for about 15 years with no problems. But a couple of years ago I was caught in a heavy snowstorm and the front grilles got almost completely covered over. I made regular stops to clear them. It hadn't occurred to me before that this could happen but shows why most car manufacturers have a very wide honeycomb design which statistically stops some stones but leaves a wide enough gap to prevent snow clogging.  Presumably Porsche fits mesh as standard to GT cars in the expectation that they won't be driven far on Cup tyres in snowstorms!    

[BBB]

I guess that if you have snow clogging, the ambient temperature is low enough to prevent overheating anyway. But, it’s a useful warning to keep an eye on coolant temperatures in snowy conditions.

Edit: my 911th post, a suitably Porsche number. Just got to keep going for 987.

Edited May 24, 2023 by BBB

[Menoporsche]

31 minutes ago, BrianJ said:

I was caught in a heavy snowstorm and the front grilles got almost completely covered over

Good point, thanks.