View Poll Results: I have had an IMS problem with my 996, 997, 986, 987
Voters: 154. You may not vote on this poll
Who has had an IMS failure?
12-04-2009, 05:03 PM
#31
Nordschleife Master
At a hundred respondents, it's probably somewhere around +/- 10%, depending on the split. If you were debating a statistician, the question would be less about sample size and more about whether or not this is a random sample of the 996 universe.
But in the end, it doesn't matter. Even if the data was perfect, it would still only be historic, not predictive.
It's just interesting, that's all.
But in the end, it doesn't matter. Even if the data was perfect, it would still only be historic, not predictive.
It's just interesting, that's all.
12-04-2009, 05:30 PM
#32
Thanks for the show of self-restraint. 
I just meant that if a phenomenon is ongoing and progressive, then a single datum on historic incidence is useless as a predictor of the future. If 10% of engines have failed, this does not mean that 10% of all unfailed engines will fail. It may mean that all of them will eventually fail, or it may mean that all that will fail have already done so, or anything in between. It's a bit like the H1N1 thing: the phenomenon will ultimately occur as a curve, which you can't really predict the shape of until after the rate of infection has peaked.
To me, the only useful data would include some correlates to failure. Oh, and a curve would be nice, too. Otherwise, this is what we call in my world being "blinded by the flash of snapshot accounting."
I just meant that if a phenomenon is ongoing and progressive, then a single datum on historic incidence is useless as a predictor of the future. If 10% of engines have failed, this does not mean that 10% of all unfailed engines will fail. It may mean that all of them will eventually fail, or it may mean that all that will fail have already done so, or anything in between. It's a bit like the H1N1 thing: the phenomenon will ultimately occur as a curve, which you can't really predict the shape of until after the rate of infection has peaked.
To me, the only useful data would include some correlates to failure. Oh, and a curve would be nice, too. Otherwise, this is what we call in my world being "blinded by the flash of snapshot accounting."
12-04-2009, 05:34 PM
#33
Nordschleife Master
Welcome
I figured it would be best if I didn't try for the millionth time to explain basic stats to the masses. Instead, I have determined that people will either worry about the unknown and fall prey to the perception created. Or........you can take the stance I have and just enjoy the #$&^%@&#*^ car and drive it with an ear-to-ear grin
I figured it would be best if I didn't try for the millionth time to explain basic stats to the masses. Instead, I have determined that people will either worry about the unknown and fall prey to the perception created. Or........you can take the stance I have and just enjoy the #$&^%@&#*^ car and drive it with an ear-to-ear grin
Last edited by LVDell; 12-04-2009 at 08:32 PM. Reason: Freudian slip
12-05-2009, 01:11 AM
#35
Rennlist Member
12-05-2009, 01:45 AM
#36
Intermediate
Join Date: Dec 2005
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
First engine replacement at 7500 miles under warranty for RMS engine block out of spec.
Second engine replacement at 59000 miles (52000 on engine) on my nickel due to IMS bearing failure.
2002 C4 cab
Second engine replacement at 59000 miles (52000 on engine) on my nickel due to IMS bearing failure.
2002 C4 cab
12-05-2009, 01:08 PM
#38
I don't want to step into the shortfalls of this type of survey - but I do find it interesting that the percent of respondents that had IMS problems has maintained at 8-10% through this whole survey. (n=77 right now)
The L&N wedsite should be required reading for anyone interested about IMS problems.
These excerpts are really interesting to me-
-------------------------------------------------------------------
Recommendations to extend IMS life from website...
"What can be done is to change your oil more often. We recommend oil changes for the M96 and later engines (as we do for air-cooled engines) every 5,000 miles. If you track your car, you should change the oil after every race weekend or every other event at the bare minimum and should also consider used oil analysis to monitor the health of your engine.
Use a higher viscosity motor oil. There are several Porsche approved oils that are 5w40, rather than Mobil 1 0w40. Use of an oil that isn't API SM-rated with more Zn and P or an oil with moly extreme pressure anti-wear additives may improve engine life. Timken Falex bearing tests tend to indicate increased load capacity and less wear scarring with oils with high levels of moly as documented here and may prolong the IMS bearing life. To learn more about motor oils and which ones might be better for your Boxster, Cayman, or 911 model, click here.
On a new or remanufactured engine the only "preventative" measure that can be taken short of our retrofit kits is to remove the seal off the front of the IMS bearing, to allow for better lubrication of the bearing. With proper lubrication and more frequent oil changes, longevity of your original IMS can be greatly extended. Our retrofit kits use ceramic bearings with significantly longer service life and come with seals removed for improved oiling as well."
----------------------------------------------------------
Interesting comment about failure rate from website....
"Thanks to a fellow Porsche Boxster owner who is also a retired bearing engineer who worked for Timken Bearing, we have gained much insight towards the root causes of intermediate shaft failures. Here's the reader's digest version of his bearing analysis and how LN Engineering has used this information in developing its IMS solutions. By their estimates, they figure a 90% survival rate of the bearing used in the IMS at 90,000 miles* - resulting in a staggering 10% failure rate (called the Ll0 life)! *Assuming an average speed of 60mph in top gear."
-------------------------------------------------------------------------------------
Comments about IMS seal and lubrication...
"The main problem stems from the use of a sealed bearing. Although the seals are intended to keep oil out of the IMS tube and keep the permanent lubricant in the bearing, neither happens.
On engines observant of factory recommended long drain intervals, oil heavily laden from fuel or just dirty from too long of drain intervals provides poor lubrication for the IMS bearing. Even .002% water in the oil can reduce bearing life by up to 48%. Higher moisture levels up to 6% can reduce bearing life by up to 83%. Excessive oil temperatures also have a negative effect on bearing life - the life of the permanent lubricant used in these bearings is cut in half by every 18F increase in temperature - from an uncontaminated life of up to 30 years at 86F to a useful life of only 90 days at 212F! This is why the bearing engineer recommended removing the seal and allowing the engine oil to lubricate the bearing, and why frequent changes are so important. Oils high in ZDDP and moly further improve longevity as suggested in the article referenced above. More info about ball bearings can be found here.
Now it gets more technical.... Where the exact reason for IMS failures cannot be known for sure, in the bearing analysis it was noted that bearings used in the IMS position are unusual in that they are double sealed and have outer race rotation. Bearings were found to be void of grease and had light oil in them and wear patterns in the ball grooves indicate marginal lubrication due to the relatively low viscosity of motor oil compared to grease.
In addition, conventional class 1 bearings, like the 52100-series bearing steel used in the factory bearings, is typically only stable to 250F, suffering from fatigue and weakening exposed to elevated engine temperatures that slowly affect the bearing's strength over its lifespan. Attempting to reduce engine coolant operating temperatures directly reduces oil temperatures, further improving bearing life! That's why trying to lower the coolant AND oil temperature is so important!
Computer simulation of the 6204 bearing showed that only three ***** are under load at any given time. Hertz stress is moderate. Lube film thickness is very small. Ideally it should be greater than the worst surface finish. Speed is not high enough to develop an elastohydrodynamic film to overcome surface finish/film issue. Fatigue life is high due to relative light load but with no EHD film there will be metal/metal contact and wear. With only three ***** under load at any one time the unloaded ***** will be dragged around by the ball separator. When a ball leaves the loaded zone it will tend to be driven into the separator pocket.
The engineer’s initial thoughts were that the ball-separator failure led to bearing collapse, but after analysis of said IMS bearings, it would appear that bearing wear/fatigue spalls lead to separator wear and outer race failure. Separator failure and bearing collapse causes catastrophic failure of the mounting bolt(s) and IMS/timing chain components. The first recommendation was to use a bearing without seals and secondly to use a higher viscosity oil (with greater film strength). More frequent changes will also improve lubrication quality. An oil with extreme pressure additives like Moly might also further assist in increasing bearing life. Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven "like they were stolen." Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full protential. Further recommendations by the retired Timken engineer are evident in the design of LN Engineering’s IMS upgrade and retrofit kits."
--------------------------------------------------------------------
Check out the full article- http://www.lnengineering.com/ims.html (not affiliated)
One of my planned Dec projects is to put the 996 on the lift, pull the trans, and check the IMS for play, remove the seal and reassemble for the mean time. Then consider the upgrade possibly in the spring. Also add ZDDP additives when I change the oil. The car has to last at least another 99k. (I'll report back with pics)
Just my thoughts - (not my recommendations to anyone else)
The L&N wedsite should be required reading for anyone interested about IMS problems.
These excerpts are really interesting to me-
-------------------------------------------------------------------
Recommendations to extend IMS life from website...
"What can be done is to change your oil more often. We recommend oil changes for the M96 and later engines (as we do for air-cooled engines) every 5,000 miles. If you track your car, you should change the oil after every race weekend or every other event at the bare minimum and should also consider used oil analysis to monitor the health of your engine.
Use a higher viscosity motor oil. There are several Porsche approved oils that are 5w40, rather than Mobil 1 0w40. Use of an oil that isn't API SM-rated with more Zn and P or an oil with moly extreme pressure anti-wear additives may improve engine life. Timken Falex bearing tests tend to indicate increased load capacity and less wear scarring with oils with high levels of moly as documented here and may prolong the IMS bearing life. To learn more about motor oils and which ones might be better for your Boxster, Cayman, or 911 model, click here.
On a new or remanufactured engine the only "preventative" measure that can be taken short of our retrofit kits is to remove the seal off the front of the IMS bearing, to allow for better lubrication of the bearing. With proper lubrication and more frequent oil changes, longevity of your original IMS can be greatly extended. Our retrofit kits use ceramic bearings with significantly longer service life and come with seals removed for improved oiling as well."
----------------------------------------------------------
Interesting comment about failure rate from website....
"Thanks to a fellow Porsche Boxster owner who is also a retired bearing engineer who worked for Timken Bearing, we have gained much insight towards the root causes of intermediate shaft failures. Here's the reader's digest version of his bearing analysis and how LN Engineering has used this information in developing its IMS solutions. By their estimates, they figure a 90% survival rate of the bearing used in the IMS at 90,000 miles* - resulting in a staggering 10% failure rate (called the Ll0 life)! *Assuming an average speed of 60mph in top gear."
-------------------------------------------------------------------------------------
Comments about IMS seal and lubrication...
"The main problem stems from the use of a sealed bearing. Although the seals are intended to keep oil out of the IMS tube and keep the permanent lubricant in the bearing, neither happens.
On engines observant of factory recommended long drain intervals, oil heavily laden from fuel or just dirty from too long of drain intervals provides poor lubrication for the IMS bearing. Even .002% water in the oil can reduce bearing life by up to 48%. Higher moisture levels up to 6% can reduce bearing life by up to 83%. Excessive oil temperatures also have a negative effect on bearing life - the life of the permanent lubricant used in these bearings is cut in half by every 18F increase in temperature - from an uncontaminated life of up to 30 years at 86F to a useful life of only 90 days at 212F! This is why the bearing engineer recommended removing the seal and allowing the engine oil to lubricate the bearing, and why frequent changes are so important. Oils high in ZDDP and moly further improve longevity as suggested in the article referenced above. More info about ball bearings can be found here.
Now it gets more technical.... Where the exact reason for IMS failures cannot be known for sure, in the bearing analysis it was noted that bearings used in the IMS position are unusual in that they are double sealed and have outer race rotation. Bearings were found to be void of grease and had light oil in them and wear patterns in the ball grooves indicate marginal lubrication due to the relatively low viscosity of motor oil compared to grease.
In addition, conventional class 1 bearings, like the 52100-series bearing steel used in the factory bearings, is typically only stable to 250F, suffering from fatigue and weakening exposed to elevated engine temperatures that slowly affect the bearing's strength over its lifespan. Attempting to reduce engine coolant operating temperatures directly reduces oil temperatures, further improving bearing life! That's why trying to lower the coolant AND oil temperature is so important!
Computer simulation of the 6204 bearing showed that only three ***** are under load at any given time. Hertz stress is moderate. Lube film thickness is very small. Ideally it should be greater than the worst surface finish. Speed is not high enough to develop an elastohydrodynamic film to overcome surface finish/film issue. Fatigue life is high due to relative light load but with no EHD film there will be metal/metal contact and wear. With only three ***** under load at any one time the unloaded ***** will be dragged around by the ball separator. When a ball leaves the loaded zone it will tend to be driven into the separator pocket.
The engineer’s initial thoughts were that the ball-separator failure led to bearing collapse, but after analysis of said IMS bearings, it would appear that bearing wear/fatigue spalls lead to separator wear and outer race failure. Separator failure and bearing collapse causes catastrophic failure of the mounting bolt(s) and IMS/timing chain components. The first recommendation was to use a bearing without seals and secondly to use a higher viscosity oil (with greater film strength). More frequent changes will also improve lubrication quality. An oil with extreme pressure additives like Moly might also further assist in increasing bearing life. Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven "like they were stolen." Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full protential. Further recommendations by the retired Timken engineer are evident in the design of LN Engineering’s IMS upgrade and retrofit kits."
--------------------------------------------------------------------
Check out the full article- http://www.lnengineering.com/ims.html (not affiliated)
One of my planned Dec projects is to put the 996 on the lift, pull the trans, and check the IMS for play, remove the seal and reassemble for the mean time. Then consider the upgrade possibly in the spring. Also add ZDDP additives when I change the oil. The car has to last at least another 99k. (I'll report back with pics)
Just my thoughts - (not my recommendations to anyone else)
12-05-2009, 06:42 PM
#39
Race Car
I don't want to step into the shortfalls of this type of survey - but I do find it interesting that the percent of respondents that had IMS problems has maintained at 8-10% through this whole survey. (n=77 right now)
The L&N wedsite should be required reading for anyone interested about IMS problems.
These excerpts are really interesting to me-
-------------------------------------------------------------------
Recommendations to extend IMS life from website...
"What can be done is to change your oil more often. We recommend oil changes for the M96 and later engines (as we do for air-cooled engines) every 5,000 miles. If you track your car, you should change the oil after every race weekend or every other event at the bare minimum and should also consider used oil analysis to monitor the health of your engine.
+ had failure due to intermix. So, now I guess the number of Porsche that have had engine failures is up to 50,000+.
Use a higher viscosity motor oil. There are several Porsche approved oils that are 5w40, rather than Mobil 1 0w40. Use of an oil that isn't API SM-rated with more Zn and P or an oil with moly extreme pressure anti-wear additives may improve engine life. Timken Falex bearing tests tend to indicate increased load capacity and less wear scarring with oils with high levels of moly as documented here and may prolong the IMS bearing life. To learn more about motor oils and which ones might be better for your Boxster, Cayman, or 911 model, click here.
On a new or remanufactured engine the only "preventative" measure that can be taken short of our retrofit kits is to remove the seal off the front of the IMS bearing, to allow for better lubrication of the bearing. With proper lubrication and more frequent oil changes, longevity of your original IMS can be greatly extended. Our retrofit kits use ceramic bearings with significantly longer service life and come with seals removed for improved oiling as well."
----------------------------------------------------------
Interesting comment about failure rate from website....
"Thanks to a fellow Porsche Boxster owner who is also a retired bearing engineer who worked for Timken Bearing, we have gained much insight towards the root causes of intermediate shaft failures. Here's the reader's digest version of his bearing analysis and how LN Engineering has used this information in developing its IMS solutions. By their estimates, they figure a 90% survival rate of the bearing used in the IMS at 90,000 miles* - resulting in a staggering 10% failure rate (called the Ll0 life)! *Assuming an average speed of 60mph in top gear."
-------------------------------------------------------------------------------------
Comments about IMS seal and lubrication...
"The main problem stems from the use of a sealed bearing. Although the seals are intended to keep oil out of the IMS tube and keep the permanent lubricant in the bearing, neither happens.
On engines observant of factory recommended long drain intervals, oil heavily laden from fuel or just dirty from too long of drain intervals provides poor lubrication for the IMS bearing. Even .002% water in the oil can reduce bearing life by up to 48%. Higher moisture levels up to 6% can reduce bearing life by up to 83%. Excessive oil temperatures also have a negative effect on bearing life - the life of the permanent lubricant used in these bearings is cut in half by every 18F increase in temperature - from an uncontaminated life of up to 30 years at 86F to a useful life of only 90 days at 212F! This is why the bearing engineer recommended removing the seal and allowing the engine oil to lubricate the bearing, and why frequent changes are so important. Oils high in ZDDP and moly further improve longevity as suggested in the article referenced above. More info about ball bearings can be found here.
Now it gets more technical.... Where the exact reason for IMS failures cannot be known for sure, in the bearing analysis it was noted that bearings used in the IMS position are unusual in that they are double sealed and have outer race rotation. Bearings were found to be void of grease and had light oil in them and wear patterns in the ball grooves indicate marginal lubrication due to the relatively low viscosity of motor oil compared to grease.
In addition, conventional class 1 bearings, like the 52100-series bearing steel used in the factory bearings, is typically only stable to 250F, suffering from fatigue and weakening exposed to elevated engine temperatures that slowly affect the bearing's strength over its lifespan. Attempting to reduce engine coolant operating temperatures directly reduces oil temperatures, further improving bearing life! That's why trying to lower the coolant AND oil temperature is so important!
Computer simulation of the 6204 bearing showed that only three ***** are under load at any given time. Hertz stress is moderate. Lube film thickness is very small. Ideally it should be greater than the worst surface finish. Speed is not high enough to develop an elastohydrodynamic film to overcome surface finish/film issue. Fatigue life is high due to relative light load but with no EHD film there will be metal/metal contact and wear. With only three ***** under load at any one time the unloaded ***** will be dragged around by the ball separator. When a ball leaves the loaded zone it will tend to be driven into the separator pocket.
The engineer’s initial thoughts were that the ball-separator failure led to bearing collapse, but after analysis of said IMS bearings, it would appear that bearing wear/fatigue spalls lead to separator wear and outer race failure. Separator failure and bearing collapse causes catastrophic failure of the mounting bolt(s) and IMS/timing chain components. The first recommendation was to use a bearing without seals and secondly to use a higher viscosity oil (with greater film strength). More frequent changes will also improve lubrication quality. An oil with extreme pressure additives like Moly might also further assist in increasing bearing life. Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven "like they were stolen." Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full protential. Further recommendations by the retired Timken engineer are evident in the design of LN Engineering’s IMS upgrade and retrofit kits."
--------------------------------------------------------------------
Check out the full article- http://www.lnengineering.com/ims.html (not affiliated)
One of my planned Dec projects is to put the 996 on the lift, pull the trans, and check the IMS for play, remove the seal and reassemble for the mean time. Then consider the upgrade possibly in the spring. Also add ZDDP additives when I change the oil. The car has to last at least another 99k. (I'll report back with pics)
Just my thoughts - (not my recommendations to anyone else)
The L&N wedsite should be required reading for anyone interested about IMS problems.
These excerpts are really interesting to me-
-------------------------------------------------------------------
Recommendations to extend IMS life from website...
"What can be done is to change your oil more often. We recommend oil changes for the M96 and later engines (as we do for air-cooled engines) every 5,000 miles. If you track your car, you should change the oil after every race weekend or every other event at the bare minimum and should also consider used oil analysis to monitor the health of your engine.
+ had failure due to intermix. So, now I guess the number of Porsche that have had engine failures is up to 50,000+.
Use a higher viscosity motor oil. There are several Porsche approved oils that are 5w40, rather than Mobil 1 0w40. Use of an oil that isn't API SM-rated with more Zn and P or an oil with moly extreme pressure anti-wear additives may improve engine life. Timken Falex bearing tests tend to indicate increased load capacity and less wear scarring with oils with high levels of moly as documented here and may prolong the IMS bearing life. To learn more about motor oils and which ones might be better for your Boxster, Cayman, or 911 model, click here.
On a new or remanufactured engine the only "preventative" measure that can be taken short of our retrofit kits is to remove the seal off the front of the IMS bearing, to allow for better lubrication of the bearing. With proper lubrication and more frequent oil changes, longevity of your original IMS can be greatly extended. Our retrofit kits use ceramic bearings with significantly longer service life and come with seals removed for improved oiling as well."
----------------------------------------------------------
Interesting comment about failure rate from website....
"Thanks to a fellow Porsche Boxster owner who is also a retired bearing engineer who worked for Timken Bearing, we have gained much insight towards the root causes of intermediate shaft failures. Here's the reader's digest version of his bearing analysis and how LN Engineering has used this information in developing its IMS solutions. By their estimates, they figure a 90% survival rate of the bearing used in the IMS at 90,000 miles* - resulting in a staggering 10% failure rate (called the Ll0 life)! *Assuming an average speed of 60mph in top gear."
-------------------------------------------------------------------------------------
Comments about IMS seal and lubrication...
"The main problem stems from the use of a sealed bearing. Although the seals are intended to keep oil out of the IMS tube and keep the permanent lubricant in the bearing, neither happens.
On engines observant of factory recommended long drain intervals, oil heavily laden from fuel or just dirty from too long of drain intervals provides poor lubrication for the IMS bearing. Even .002% water in the oil can reduce bearing life by up to 48%. Higher moisture levels up to 6% can reduce bearing life by up to 83%. Excessive oil temperatures also have a negative effect on bearing life - the life of the permanent lubricant used in these bearings is cut in half by every 18F increase in temperature - from an uncontaminated life of up to 30 years at 86F to a useful life of only 90 days at 212F! This is why the bearing engineer recommended removing the seal and allowing the engine oil to lubricate the bearing, and why frequent changes are so important. Oils high in ZDDP and moly further improve longevity as suggested in the article referenced above. More info about ball bearings can be found here.
Now it gets more technical.... Where the exact reason for IMS failures cannot be known for sure, in the bearing analysis it was noted that bearings used in the IMS position are unusual in that they are double sealed and have outer race rotation. Bearings were found to be void of grease and had light oil in them and wear patterns in the ball grooves indicate marginal lubrication due to the relatively low viscosity of motor oil compared to grease.
In addition, conventional class 1 bearings, like the 52100-series bearing steel used in the factory bearings, is typically only stable to 250F, suffering from fatigue and weakening exposed to elevated engine temperatures that slowly affect the bearing's strength over its lifespan. Attempting to reduce engine coolant operating temperatures directly reduces oil temperatures, further improving bearing life! That's why trying to lower the coolant AND oil temperature is so important!
Computer simulation of the 6204 bearing showed that only three ***** are under load at any given time. Hertz stress is moderate. Lube film thickness is very small. Ideally it should be greater than the worst surface finish. Speed is not high enough to develop an elastohydrodynamic film to overcome surface finish/film issue. Fatigue life is high due to relative light load but with no EHD film there will be metal/metal contact and wear. With only three ***** under load at any one time the unloaded ***** will be dragged around by the ball separator. When a ball leaves the loaded zone it will tend to be driven into the separator pocket.
The engineer’s initial thoughts were that the ball-separator failure led to bearing collapse, but after analysis of said IMS bearings, it would appear that bearing wear/fatigue spalls lead to separator wear and outer race failure. Separator failure and bearing collapse causes catastrophic failure of the mounting bolt(s) and IMS/timing chain components. The first recommendation was to use a bearing without seals and secondly to use a higher viscosity oil (with greater film strength). More frequent changes will also improve lubrication quality. An oil with extreme pressure additives like Moly might also further assist in increasing bearing life. Higher rpms also increases bearing life as this lessens the viscosity requirements of the lubricant to maintain EHD lubrication, also providing a reasonable explanation of the lack of IMS failures in tracked cars or those driven "like they were stolen." Likewise, far more failures are found in engines with low mileage that are garage queens and never driven to their full protential. Further recommendations by the retired Timken engineer are evident in the design of LN Engineering’s IMS upgrade and retrofit kits."
--------------------------------------------------------------------
Check out the full article- http://www.lnengineering.com/ims.html (not affiliated)
One of my planned Dec projects is to put the 996 on the lift, pull the trans, and check the IMS for play, remove the seal and reassemble for the mean time. Then consider the upgrade possibly in the spring. Also add ZDDP additives when I change the oil. The car has to last at least another 99k. (I'll report back with pics)
Just my thoughts - (not my recommendations to anyone else)
12-05-2009, 07:41 PM
#41
Race Car
It almost make me want to believe the climate statistics being used.
12-06-2009, 06:43 AM
#43
Racer
Well Well -- it might be F-up'ed -- so let that be an incentive for someone to do it better -- for if we do not try to do it better what are we but a bunch of....? no won't say it... not nice...
So if this is a poor job (and good on the thread starter for trying) it is time for someone to do a proper job -- and by the previous posts there are a few of you who know stats -- so let's see you do it properly.
And -- if it is a 10% death rate over 200,000 miles then that is what it is -- so be it.
I have just returned from a 500 mile in 2 day drive around a coast road (Princes Hwy) and wow -- what a car!!!
So if this is a poor job (and good on the thread starter for trying) it is time for someone to do a proper job -- and by the previous posts there are a few of you who know stats -- so let's see you do it properly.
And -- if it is a 10% death rate over 200,000 miles then that is what it is -- so be it.
I have just returned from a 500 mile in 2 day drive around a coast road (Princes Hwy) and wow -- what a car!!!
12-06-2009, 09:45 AM
#44
Nordschleife Master
No, not good for starting it as it will go nowhere just like the last million of these IMS "statistic" threads.
As a stats professor I can tell you with 100% certainty, the only way to do this properly is to take it OFF rennlist and have access to the population we need to sample. I'll tell you there is NO access to that sample unless you want to do some mission impossible type crap at PCNA.......
12-06-2009, 10:09 AM
#45
Racer
Thanks for constructive crit' LVDell.
So -- you seem to be saying that do do a proper survey we would need to get Porsche's stats?
If that is correct -- is seems you are saying a 100% sample is needed -- and if that is correct then how do pollsters do their work with sample groups?
Now I do understand that Mr Phelps is not driving us to we won't get MI orders but how do we get some guidance and direction? Please lead us to the place of understanding.
And this gets a bit lateral here -- can an estimation be done by looking at stats like the number of head gaskets produced for 3.4's and 3.6's (could someone id and then ask/search the manufacturer?) and then deduct the No. used for production and the number for the spares shelf.
Or -- do you in the US have a law like we have here in Australia where you can get a Court Order seeking information from any "possible" defendant -- to see if there is a product liability case?
See below -- regrettably the Aust law is not quite on point -- but we are a bit behind the USA in product liability law so you may have the mechanism.
MAGISTRATES' COURT CIVIL PROCEDURE RULES 2009 - SECT 13.03.
Discovery to identify a defendant
13.03. Discovery to identify a defendant
(1) If an applicant, having made reasonable inquiries, is unable to ascertain
the description of a person sufficiently for the purpose of commencing a
proceeding in the Court against that person (in this Rule called the person
concerned) and it appears that some person has or is likely to have knowledge
of facts, or has or is likely to have or has had or is likely to have had in
the person's possession any document or thing, tending to assist in such
ascertainment, the Court may make an order under paragraph (2).
(2) The Court may order that the person, and in the case of a corporation,
the corporation by an appropriate officer, must-
(a) attend before the Court to be orally examined in relation to the
description of the person concerned;
(b) make discovery to the applicant of all documents which are or have
been in the possession of the person or the corporation relating to
the description of the person concerned.
(3) If the Court makes an order under paragraph (2)(a), it may order that the
person or corporation against whom or which the order is made shall produce to
the Court on the examination any document or thing in the person's or
the corporation's possession relating to the description of the person
concerned.
So -- you seem to be saying that do do a proper survey we would need to get Porsche's stats?
If that is correct -- is seems you are saying a 100% sample is needed -- and if that is correct then how do pollsters do their work with sample groups?
Now I do understand that Mr Phelps is not driving us to we won't get MI orders but how do we get some guidance and direction? Please lead us to the place of understanding.
And this gets a bit lateral here -- can an estimation be done by looking at stats like the number of head gaskets produced for 3.4's and 3.6's (could someone id and then ask/search the manufacturer?) and then deduct the No. used for production and the number for the spares shelf.
Or -- do you in the US have a law like we have here in Australia where you can get a Court Order seeking information from any "possible" defendant -- to see if there is a product liability case?
See below -- regrettably the Aust law is not quite on point -- but we are a bit behind the USA in product liability law so you may have the mechanism.
MAGISTRATES' COURT CIVIL PROCEDURE RULES 2009 - SECT 13.03.
Discovery to identify a defendant
13.03. Discovery to identify a defendant
(1) If an applicant, having made reasonable inquiries, is unable to ascertain
the description of a person sufficiently for the purpose of commencing a
proceeding in the Court against that person (in this Rule called the person
concerned) and it appears that some person has or is likely to have knowledge
of facts, or has or is likely to have or has had or is likely to have had in
the person's possession any document or thing, tending to assist in such
ascertainment, the Court may make an order under paragraph (2).
(2) The Court may order that the person, and in the case of a corporation,
the corporation by an appropriate officer, must-
(a) attend before the Court to be orally examined in relation to the
description of the person concerned;
(b) make discovery to the applicant of all documents which are or have
been in the possession of the person or the corporation relating to
the description of the person concerned.
(3) If the Court makes an order under paragraph (2)(a), it may order that the
person or corporation against whom or which the order is made shall produce to
the Court on the examination any document or thing in the person's or
the corporation's possession relating to the description of the person
concerned.