Replace nose panel?
12-01-2014, 02:46 PM
#31
Rennlist Junkie Forever
Exactly.
This being on 924 front end.
On a 951 nose that same difference would even be greater based on the shape of the 951 nose relative to the header panel.
The problem being you have high pressure entering one hole (the bottom factory hole) and a lower pressure air trying to enter the top hole (the aftermarket vent holes).
Air takes the path of least resistance.
So just based on the pressure differential alone... the aftermarket vent holes should not only not function as intended... but may even relieve pressure generated by the factory holes... which would result in less air through the intercooler.
I will say this though... on the vented header panels which "reshape" the the header panel (like Patrick's old header panel) so that the aftermarket holes "stand up".... That panel may (probably) work because it creates a high pressure area due to it's vertical face.
TonyG
This being on 924 front end.
On a 951 nose that same difference would even be greater based on the shape of the 951 nose relative to the header panel.
The problem being you have high pressure entering one hole (the bottom factory hole) and a lower pressure air trying to enter the top hole (the aftermarket vent holes).
Air takes the path of least resistance.
So just based on the pressure differential alone... the aftermarket vent holes should not only not function as intended... but may even relieve pressure generated by the factory holes... which would result in less air through the intercooler.
I will say this though... on the vented header panels which "reshape" the the header panel (like Patrick's old header panel) so that the aftermarket holes "stand up".... That panel may (probably) work because it creates a high pressure area due to it's vertical face.
TonyG
12-01-2014, 03:08 PM
#32
But Really the problem, is that there is NO exhaust. frankly and exhaust would do MORE than more intake.
Sure both would be best.
but look at the 968TRS
Yes that is a 924
12-01-2014, 03:51 PM
#34
Freedom Enthusiast
Rennlist Member
Rennlist Member
Porsche 944
I am not sure if this is the diagram people are referring to but if it is accurate it might be helpful. The trick when reading it is to realise the graph underneath doesn't directly relate to the diagram but to the plotted points on the diagram, which start at 1 next to the wheelarch then go forward around the bumper and then onto the car. It seems just before point 10 to point 17 are all low pressure. By the look of the diagram this is for a 944 not a 951.
Will be very interested to see the results of any testing.
NO, its point 8, and look at the POSITIVE pressure. Point 10 correlates with the top edge of that "flat" section, and would correctly show negative pressure just like the high point on a wing.
But Really the problem, is that there is NO exhaust. frankly and exhaust would do MORE than more intake.
Sure both would be best.
but look at the 968TRS
Yes that is a 924
But Really the problem, is that there is NO exhaust. frankly and exhaust would do MORE than more intake.
Sure both would be best.
but look at the 968TRS
Yes that is a 924
This graph is from a 924 and the graph from a 951 would look different.
Without proper ducting and proper wind tunnel testing, there is no way to know what is really happening.
12-01-2014, 04:23 PM
#35
The graphic of the car and the number graph are not to the same scale. You must look at the points/dots on the car and then find them on the number graph. The point where most header panel openings are located are about point 9 on the car and the number graph. point 8 is the leading edge of the very top of the bumper.
This graph is from a 924 and the graph from a 951 would look different.
Without proper ducting and proper wind tunnel testing, there is no way to know what is really happening.
This graph is from a 924 and the graph from a 951 would look different.
Without proper ducting and proper wind tunnel testing, there is no way to know what is really happening.
I highly doubt there is much difference in this spot between the 924 and 951.
also lets not forget the 924gtr and GTP both used vents in this spot.
It probably creates more drag.
Also if youll notice the new Camaro and vette have vents at similar spots
12-01-2014, 06:10 PM
#36
Rennlist Member
yes sorry you're right, I put the wrong number in, point 9 has the positive pressure and thats where the "intake" should be.
I highly doubt there is much difference in this spot between the 924 and 951.
also lets not forget the 924gtr and GTP both used vents in this spot.
It probably creates more drag.
Also if youll notice the new Camaro and vette have vents at similar spots
I highly doubt there is much difference in this spot between the 924 and 951.
also lets not forget the 924gtr and GTP both used vents in this spot.
It probably creates more drag.
Also if youll notice the new Camaro and vette have vents at similar spots
12-01-2014, 06:30 PM
#37
Rennlist Member
Wasn't me that had the LR header panel Tony. Couldn't stomach the look back then. Now we have no vented header panel.
I agree that the outlet is more important for extraction. Especially with sufficiently designed vents.
I agree that the outlet is more important for extraction. Especially with sufficiently designed vents.
12-01-2014, 09:30 PM
#38
Drifting
Front pic
We're considering replacing this with a factory nose panel, but haven't made the decision yet. My power steering cooler is just behind the passenger side inlet on the nose and the air flow likely helps keep the rack fluid cooler. We don't see any other benefit from readings to date.
G
G
12-01-2014, 10:21 PM
#39
Drifting
Maybe the 968 S/RS is different but I'm inclined to fit some small NACA ducts in a similar position on my 944, and some small vents further back on the hood. I know one of the 968T ducts feeds the air filter.