991
Sponsored by:
Sponsored by:

Buffeting (not Jimmy)

Old Apr 7, 2012 | 10:18 AM
  #1  
AG991's Avatar
Thread Starter
|
Registered User
Joined: Feb 2012
Posts: 1,479
From: New Jersey
Rep Power: 102
AG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond repute
Buffeting (not Jimmy)

At reasonably low speeds (30 mph), when I have the sunroof open, I get considerable buffeting. Some trace is apparent when I have it closed and the driver side window is open, but only if you listen for it and at much higher speeds. At least one other has commented that they have serious buffeting from the driver side window but not the sunroof. Can anyone help with the causes and possible fixes? Can anyone explain why two of the same cars have the same issue in different openings?

Is anyone else having the same problems?
 
Old Apr 7, 2012 | 11:11 AM
  #2  
hed's Avatar
hed
Registered User
Joined: Jun 2011
Posts: 107
Rep Power: 21
hed is a jewel in the roughhed is a jewel in the roughhed is a jewel in the rough
Originally Posted by AG991
At reasonably low speeds (30 mph), when I have the sunroof open, I get considerable buffeting. Some trace is apparent when I have it closed and the driver side window is open, but only if you listen for it and at much higher speeds. At least one other has commented that they have serious buffeting from the driver side window but not the sunroof. Can anyone help with the causes and possible fixes? Can anyone explain why two of the same cars have the same issue in different openings?

Is anyone else having the same problems?
I would be curious as well. I have had cars that had this problem and it always annoyed me.
 
Old Apr 7, 2012 | 11:14 AM
  #3  
jmmk's Avatar
Registered User
Joined: Feb 2010
Posts: 148
From: Dallas TX
Rep Power: 27
jmmk is a name known to alljmmk is a name known to alljmmk is a name known to alljmmk is a name known to alljmmk is a name known to alljmmk is a name known to all
If any opening is available, the aerodynamics of the car are altered. Air can either get in or get out. Usually it gets in. But when it gets in, it increases the inside air pressure until it must get out. This is a problem in any car and varies with the size of the opening and the speed of the car. It can be mitigated to some degree by sizing the opening differently or moving it, but that can be thwarted by outside drafts independent of the slipstream the car creates.

The solution: speed up (or slow down); roll up or down one or both windows; close or adjust the opening of the sunroof; wait for a less windy day; and, the list goes on. It is physics, not design that makes buffeting a moving target rather than a static or wind tunnel event.
 
Old Apr 8, 2012 | 05:17 AM
  #4  
AG991's Avatar
Thread Starter
|
Registered User
Joined: Feb 2012
Posts: 1,479
From: New Jersey
Rep Power: 102
AG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond repute
Originally Posted by jmmk
If any opening is available, the aerodynamics of the car are altered. Air can either get in or get out. Usually it gets in. But when it gets in, it increases the inside air pressure until it must get out. This is a problem in any car and varies with the size of the opening and the speed of the car. It can be mitigated to some degree by sizing the opening differently or moving it, but that can be thwarted by outside drafts independent of the slipstream the car creates.

The solution: speed up (or slow down); roll up or down one or both windows; close or adjust the opening of the sunroof; wait for a less windy day; and, the list goes on. It is physics, not design that makes buffeting a moving target rather than a static or wind tunnel event.
So don't yell at the dealer-just deal with it. I am sure your right, but some designs are prone to this - first Merc. SUVs were famous for it - you could not open the back windows! It was a big item in their first redesign. I hope someone in Stuttgart is reading this, hint, hint.
 
Old Apr 8, 2012 | 07:31 AM
  #5  
jmmk's Avatar
Registered User
Joined: Feb 2010
Posts: 148
From: Dallas TX
Rep Power: 27
jmmk is a name known to alljmmk is a name known to alljmmk is a name known to alljmmk is a name known to alljmmk is a name known to alljmmk is a name known to all
Originally Posted by AG991
So don't yell at the dealer-just deal with it. I am sure your right, but some designs are prone to this - first Merc. SUVs were famous for it - you could not open the back windows! It was a big item in their first redesign. I hope someone in Stuttgart is reading this, hint, hint.
This re-design, the 991 with its new, larger sunroof, addresses this problem which was much more prevalent in 997's, 996's and 993's (that's as far back as I go). It would take a big re-design to fix the little that's left.
 
Old Apr 8, 2012 | 07:33 AM
  #6  
AG991's Avatar
Thread Starter
|
Registered User
Joined: Feb 2012
Posts: 1,479
From: New Jersey
Rep Power: 102
AG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond repute
Originally Posted by jmmk
This re-design, the 991 with its new, larger sunroof, addresses this problem which was much more prevalent in 997's, 996's and 993's (that's as far back as I go). It would take a big re-design to fix the little that's left.
Thanks. MIT is a small problem for me in the grand scheme of things, but I might have not ordered it if I had known - I still might have. Thanks four your help and thoughtful advice!
 
Old Apr 15, 2012 | 07:29 AM
  #7  
Scott997's Avatar
Registered User
Joined: Jun 2009
Posts: 606
From: South Florida
Rep Power: 90
Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !
AG991,
I'm so suprised its taken this long for this subject to be discussed! The wind buffeting with the side windows down from 110mph and up is unbareable. The only way to get relief is to open your sunroof. or close your windows. I experienced this on the racetrack. It is not a minor thing either its downright violent and hurts your ears even with a helmet on!!! Thank you for bringing it up.

I love the 991 but this wasn't a problem in the 997. This needs to be addressed in the 991 GT3. Most have no sunroof and at most track events windows need to be down. I can't imagine driving daytona with that.
 
Old Apr 15, 2012 | 08:31 AM
  #8  
buck986's Avatar
Registered User
Joined: Jan 2008
Posts: 2,759
From: NJ
Rep Power: 185
buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !
Originally Posted by Scott997
AG991,
I'm so suprised its taken this long for this subject to be discussed! The wind buffeting with the side windows down from 110mph and up is unbareable. The only way to get relief is to open your sunroof. or close your windows. I experienced this on the racetrack. It is not a minor thing either its downright violent and hurts your ears even with a helmet on!!! Thank you for bringing it up.

I love the 991 but this wasn't a problem in the 997. This needs to be addressed in the 991 GT3. Most have no sunroof and at most track events windows need to be down. I can't imagine driving daytona with that.
Scott,

this is important info for those of us who track their 911's.

So with both windows down and sunroof closed the wind buffering is really bad. ( i just want to make sure I have this correct.) This is not an issue with a 997...at least with mine its not.

I don't think you can do DE's with the sunroof open. This is serious for us who track and I have to believe this will be addressed by Porsche.
 
Old Apr 15, 2012 | 08:42 AM
  #9  
Scott997's Avatar
Registered User
Joined: Jun 2009
Posts: 606
From: South Florida
Rep Power: 90
Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !Scott997 Is a GOD !
Originally Posted by buckwheat986
Scott,

this is important info for those of us who track their 911's.

So with both windows down and sunroof closed the wind buffering is really bad. ( i just want to make sure I have this correct.) This is not an issue with a 997...at least with mine its not.

I don't think you can do DE's with the sunroof open. This is serious for us who track and I have to believe this will be addressed by Porsche.

Yes this is correct. Windows down, sunroof closed, excess of 100mph buffeting is very bad. Past 120mph its painful. Opening the sunroof relieves that pressure, or just go windows up. Depending on the clubs rules.

At PBIR I just open my sunroof, or soon will be driving with windows shut and AC on.

This was never a problem in 997. I'm not complaining about it just stating the facts.
 
Old Apr 15, 2012 | 09:13 AM
  #10  
buck986's Avatar
Registered User
Joined: Jan 2008
Posts: 2,759
From: NJ
Rep Power: 185
buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !
Originally Posted by Scott997
Yes this is correct. Windows down, sunroof closed, excess of 100mph buffeting is very bad. Past 120mph its painful. Opening the sunroof relieves that pressure, or just go windows up. Depending on the clubs rules.

At PBIR I just open my sunroof, or soon will be driving with windows shut and AC on.

This was never a problem in 997. I'm not complaining about it just stating the facts.
thanks Scott...these are important facts.....
 
Old Apr 15, 2012 | 10:44 AM
  #11  
SM_ATL's Avatar
Registered User
10 Year Member
Joined: Feb 2012
Posts: 2,166
From: Brussels
Rep Power: 159
SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !SM_ATL Is a GOD !
Originally Posted by Scott997
Yes this is correct. Windows down, sunroof closed, excess of 100mph buffeting is very bad. Past 120mph its painful. Opening the sunroof relieves that pressure, or just go windows up. Depending on the clubs rules.

At PBIR I just open my sunroof, or soon will be driving with windows shut and AC on.

This was never a problem in 997. I'm not complaining about it just stating the facts.
I confirm the issue. First time I hit 120mph+ on the track with the windows down, it was so bad I thought something was wrong with the car
Back at the track next week. Will see if I can find a fix...
 
Old Apr 15, 2012 | 10:55 AM
  #12  
buck986's Avatar
Registered User
Joined: Jan 2008
Posts: 2,759
From: NJ
Rep Power: 185
buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !buck986 Is a GOD !
Originally Posted by SM_ATL
I confirm the issue. First time I hit 120mph+ on the track with the windows down, it was so bad I thought something was wrong with the car
Back at the track next week. Will see if I can find a fix...
How can Porsche let this go like this. This is not right.
 
Old Apr 15, 2012 | 11:33 AM
  #13  
AG991's Avatar
Thread Starter
|
Registered User
Joined: Feb 2012
Posts: 1,479
From: New Jersey
Rep Power: 102
AG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond repute
I found it to be a problem at lower speeds (85) on a highway with only the drivers window open. And a number of tracks will not let you run with the sunroof openor the windows up
 
Old Apr 15, 2012 | 11:37 AM
  #14  
hroussard's Avatar
Registered User
Joined: Nov 2004
Posts: 2,154
Rep Power: 198
hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !hroussard Is a GOD !
And what does the dealer / Porsche say??? Any official word(s)??
 
Old Apr 15, 2012 | 11:45 AM
  #15  
AG991's Avatar
Thread Starter
|
Registered User
Joined: Feb 2012
Posts: 1,479
From: New Jersey
Rep Power: 102
AG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond reputeAG991 has a reputation beyond repute
Originally Posted by hroussard
And what does the dealer / Porsche say??? Any official word(s)??
I am at mine tomorrow and will ask. What they say publicly is probably that there is no problem if you operate within posted speed limits.

The back side windows should be openable as pop-out vents. Would not cost much, or play with the structural integrity.
 

Thread Tools
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -6. The time now is 01:39 PM.