Pollen filter
06-24-2002, 03:52 PM
#1
Drifting
Thread Starter
Pollen filter
Yesterday I checked the pollen filter on my 01 911, mostly because I was curious as to where/how it was mounted in comparison to the Lexus. To my great surprise it was completely clogged! 9k miles, 1600 in Europe, 3500 from POE, and the rest local, no dirt roads, etc.
Within the last year or so I have changed out the pollen filters on a 95 LS (20k mile interval), a 00 GS3 (8k miles), and an 01 RX (15k miles). None of the Lexus filters were even close to being clogged.
What gives?
Now I know that Lexus strives mightily to reduce the blower speed to achieve QUIET, and I also know that one of the reasons they can do that is the Lexus products do not allow much atmospheric "leakage", very little "outflow" of stale cabin air.
Using previously "conditioned" airflow, recirculated again and again, allows them to keep the cycling of the A/C compressor fairly low and thus their MPG numbers artificially high.
But the airflow outlet ducts for the 911 are even smaller than any of the Lexus products of which I am familiar. Maybe the difference is that Porsche keeps the blower speed up fairly high, creating a higher level of outlet flow due to air pressure.
Or maybe the actual exhauster airflow for the 911 is into an aerodynamic low pressure area, unlike the Lexus products wherein the "exhauster" outlet is always within an aerodynamically created high pressure area, under the rear quarter panel.
My wife and I have both noticed that we become drowsier on long trips in the Lexus vs the 911, do you suppose the excitement of driving the 911 keeps us wide awake or is it the low oxygen content along with the comfort and quiet in the Lexus? Or maybe some of each?
Has anyone used a CO2 sensor in their Lexus to see just how bad things get on a long drive?
Within the last year or so I have changed out the pollen filters on a 95 LS (20k mile interval), a 00 GS3 (8k miles), and an 01 RX (15k miles). None of the Lexus filters were even close to being clogged.
What gives?
Now I know that Lexus strives mightily to reduce the blower speed to achieve QUIET, and I also know that one of the reasons they can do that is the Lexus products do not allow much atmospheric "leakage", very little "outflow" of stale cabin air.
Using previously "conditioned" airflow, recirculated again and again, allows them to keep the cycling of the A/C compressor fairly low and thus their MPG numbers artificially high.
But the airflow outlet ducts for the 911 are even smaller than any of the Lexus products of which I am familiar. Maybe the difference is that Porsche keeps the blower speed up fairly high, creating a higher level of outlet flow due to air pressure.
Or maybe the actual exhauster airflow for the 911 is into an aerodynamic low pressure area, unlike the Lexus products wherein the "exhauster" outlet is always within an aerodynamically created high pressure area, under the rear quarter panel.
My wife and I have both noticed that we become drowsier on long trips in the Lexus vs the 911, do you suppose the excitement of driving the 911 keeps us wide awake or is it the low oxygen content along with the comfort and quiet in the Lexus? Or maybe some of each?
Has anyone used a CO2 sensor in their Lexus to see just how bad things get on a long drive?
06-24-2002, 04:28 PM
#2
Rennlist Member
Keeping air re-circulating in a car is a baaaaad idea. Every car manual I've read says so, common sense says so. I can't believe that the Lexus keeps it in recirculate mode for prolonged periods. Drowsy on long drives? DANGER!! WILL ROBINSON!!! That's CO poisoning!!. Much, much more dangerous than CO2 poisoning.
06-24-2002, 04:40 PM
#3
Drifting
Thread Starter
I have the shop manuals for ALL of the Lexus vehicles involved. Lexus goes to great (design)pains to be sure the cabin atmosphere is recirculated, even to the extent of having the system predominantly in recirculate while indicating "fresh" mode.
Does anyone know where the 996 exhauster airflow outlet is actually located?
I can see the interior ductwork at each side of the base of the rear window but where is the "outlet" end of this duct located?
Does anyone know where the 996 exhauster airflow outlet is actually located?
I can see the interior ductwork at each side of the base of the rear window but where is the "outlet" end of this duct located?
