Crown

Board: Porsche Language: English Region: Worldwide Share/Save/Bookmark Close

Forum - Thread

    Feb 11, 2006 8:20:53 PM

    teflon
    Co-Pilot
    teflon
    Loc: US , United States
    Posts: 216, Gallery
    Registered on: Mar 13, 2003

    I need help locating a post

    Someone posted a scan from a magazine within the last week or so(I think) that showed the torsional stiffness values for a number of cars. I only glanced at the post and I don't even remember now which cars were listed.

    I have been looking for this post for several hours and can't seem to find it. I have obviously been working hard, but not smart.

    Can anyone help me locate this post or direct me to where I might find this information? Or, more specifically, the torsional stiffness(the actual number) for the Carrera GT, GT2, GT3 and Cayman S.

    Thank you in advance.

    Greg A

    Feb 17, 2006 9:52:28 PM

    MAVERICK Offline
    Veteran
    MAVERICK
    Loc: Cincinnati, OH (USA) , United States
    Posts: 1145, Gallery
    Registered on: May 31, 2004
    Reply to: teflon

    Re: I need help locating a post

    teflon,

    Any success?

    Feb 23, 2006 4:46:16 PM

    teflon
    Co-Pilot
    teflon
    Loc: US , United States
    Posts: 216, Gallery
    Registered on: Mar 13, 2003
    Reply to: MAVERICK

    Re: I need help locating a post

    Maverick,

    Sorry, I missed your post until now. Thank you for your interest.

    Unfortunately, no. Maybe I've gone crazy and imagined the post's existence.

    Greg A

    Feb 25, 2006 12:07:07 AM

    MAVERICK Offline
    Veteran
    MAVERICK
    Loc: Cincinnati, OH (USA) , United States
    Posts: 1145, Gallery
    Registered on: May 31, 2004
    Reply to: teflon

    Re: I need help locating a post

    Quote:
    teflon said:
    Maybe I've gone crazy and imagined the post's existence.




    I know I'm crazy so here are approximate numbers I was able to find from Google and the Rennteam search feature:

    Static Torsional Rigidity:

    Cayenne -- 36,900 Nm/degree
    Source:
    www21.porscheengineering.com/pdf/1-2003_PE-Magazine_e.pdf

    996 GT3 Mk II -- 25% more than 996 C4 narrow-body
    The steel foundation for the bodyshell of the 911 GT3 comes as before from the 911 Carrera 4. To match the enhanced performance of this new sports car, the bodyshell has been further reinforced at all essential points, thus offering an even higher standard of passive safety and enabling the new 911 GT3 to pass all the requisite crash tests with flying colours. At the same time these reinforcements serve to increase static torsional stability by no less than 25 per cent, providing ideal conditions for stable roadholding and exact suspension control.
    Source: http://www.rennteam.com/showflat.php?Cat...h=true#Post8096

    CGT -- 26,000
    Source:
    http://www.pistonheads.com/roadtests/doc.asp?c=105&i=8496

    Cayman S -- 31,500
    911 Coupe (997) -- 31,500
    ...approximately 31,500 Newton metres per degree is almost the same as on the 911 Coupé, meaning that it would take the maximum torque of approximately 92 Cayman S engines to bend the body of the car by just 1*. This extremely high level of stiffness has direct repercussions on the precision of the chassis and suspension. With even severe bumps on the road having only a minor effect on the geometry of the body structure, the geometry of the chassis and suspension remains almost unchanged even when the going gets tough, the Cayman S driving like on those proverbial rails.
    Source: http://www.schwab-kolb.com/porsche/en/porpr121.htm

    Another old thread mentions additional interesting numbers:
    http://www.rennteam.com/showflat.php?Cat...=11&fpart=1

    996 C2 -- 16,500
    Source:
    http://www.pistonheads.com/gassing/topic.asp?f=70&t=94016

    Now for some faulty calculations:

    If the 996 GT3 Mk II is approximately 25% stiffer than the normal 996 C2/C4 narrow-body (16,500), and if we assume that the GT2 is 25% stiffer than the 996 TT (a whopping 27,000 which does not make sense), the 996 GT2 may possibly have a torsional rigidity of 33750 which is more than the 996 GT3's estimated 20,625 but still less than the Cayenne.

    Feb 25, 2006 3:02:32 AM

    RCA
    Rennteam Administrator
    RC
    Loc: Rennteam HQ , Germany
    Posts: 59590, Gallery
    Registered on: Mar 26, 2002
    Reply to: teflon

    Re: I need help locating a post

    Quote:
    teflon said:
    Someone posted a scan from a magazine within the last week or so(I think) that showed the torsional stiffness values for a number of cars. I only glanced at the post and I don't even remember now which cars were listed.

    I have been looking for this post for several hours and can't seem to find it. I have obviously been working hard, but not smart.

    Can anyone help me locate this post or direct me to where I might find this information? Or, more specifically, the torsional stiffness(the actual number) for the Carrera GT, GT2, GT3 and Cayman S.

    Thank you in advance.

    Greg A




    Maybe this one?

    http://www.rennteam.com/showflat.php?Cat...true#Post106673

    Feb 25, 2006 1:47:36 PM

    Michael Russell
    Junior
    Michael Russell
    Loc:
    Posts: 109, Gallery
    Registered on: Aug 26, 2003
    Reply to: RCA

    Re: I need help locating a post

    Brilliant post MAVERICK, very interesting.

    Michael

    Feb 25, 2006 5:10:12 PM

    MAVERICK Offline
    Veteran
    MAVERICK
    Loc: Cincinnati, OH (USA) , United States
    Posts: 1145, Gallery
    Registered on: May 31, 2004
    Reply to: Michael Russell

    Re: I need help locating a post

    Quote:
    Michael Russell said:
    Brilliant post MAVERICK, very interesting.




    You are generous with your praise, Michael. Thank you.

    Feb 25, 2006 5:19:56 PM

    Lazy Cat
    Pilot
    Lazy Cat
    Loc: On the Sofa
    Posts: 422, Gallery
    Registered on: Mar 2, 2005
    Reply to: MAVERICK

    Re: I need help locating a post

    i don't really undersand how the Cayenne can have a better torsional rigidity than a piece of carbon fiber like the cgt....that sounds odd. Maybe the cgt is too wide or too long.

    Feb 25, 2006 9:10:25 PM

    MAVERICK Offline
    Veteran
    MAVERICK
    Loc: Cincinnati, OH (USA) , United States
    Posts: 1145, Gallery
    Registered on: May 31, 2004
    Reply to: Lazy Cat

    Re: I need help locating a post

    Quote:
    Lazy Cat said:
    i don't really undersand how the Cayenne can have a better torsional rigidity than a piece of carbon fiber like the cgt....that sounds odd. Maybe the cgt is too wide or too long.



    One reason of many is the Cayenne has an integrated roof.

    According to a Porsche project leader, a convertible loses approx. 70% of its torsional rigidity.
    Source: http://telegraph.co.uk/motoring/main.jhtml?xml=/motoring/2005/04/30/mfpors30.xml

    If the CGT only lost a conservative 50% of its rigidity by being a roadster, then it might have had a minimum of approx. 39,000 Nm/degree static torsional stiffness as a coupe.

    Feb 26, 2006 12:49:08 AM

    W8MM
    Rennteam Master
    W8MM
    Loc: Cincinnati, OH , United States
    Posts: 3995, Gallery
    Registered on: Aug 8, 2003
    Reply to: MAVERICK

    Re: I need help locating a post

    Quote:
    MAVERICK said:
    Now for some faulty calculations:

    If the 996 GT3 Mk II is approximately 25% stiffer than the normal 996 C2/C4 narrow-body (16,500), and if we assume that the GT2 is 25% stiffer than the 996 TT (a whopping 27,000 which does not make sense), the 996 GT2 may possibly have a torsional rigidity of 33750 which is more than the 996 GT3's estimated 20,625 but still less than the Cayenne.



    Hi Mav,

    Just to throw a wrench into the works, I asked Roland Kussmaul what the resonant frequency of the CGT chassis was when I met him at the Porsche "booth" at the 2003 Geneva auto show. He said he didn't know, but he recalled that the CGT was greatly stiffer than the 996 GT2 chassis.

    Mar 2, 2006 5:09:04 PM

    teflon
    Co-Pilot
    teflon
    Loc: US , United States
    Posts: 216, Gallery
    Registered on: Mar 13, 2003
    Reply to: W8MM

    Re: I need help locating a post

    I haven't been on the forum for a few days and it was nice to log on and see that some people had finally responded.

    Thank you all very much for the info!


    RC, that wasn't the thread I wanted, but thank you for trying.

    Maverick,

    The numbers I found while searching were a little different. I do not know, but I think the value for the CGT is not correct. I could not find it listed anywhere in any of the official Porsche material I have.

    Thank you all for your help though! I really appreciate it.

    Greg A

    Mar 7, 2006 9:47:45 PM

    MAVERICK Offline
    Veteran
    MAVERICK
    Loc: Cincinnati, OH (USA) , United States
    Posts: 1145, Gallery
    Registered on: May 31, 2004
    Reply to: W8MM

    Re: I need help locating a post

    Quote:
    W8MM said:
    Hi Mav,

    Just to throw a wrench into the works, I asked Roland Kussmaul what the resonant frequency...



    Hi Dubya,

    Thanks for the tool . Do you know if there is a conversion factor between torsional resonant frequency (Hz) and static torsional stiffness (Nm/degree)?

    teflon,

    You are welcome.

    Mar 8, 2006 4:11:31 PM

    W8MM
    Rennteam Master
    W8MM
    Loc: Cincinnati, OH , United States
    Posts: 3995, Gallery
    Registered on: Aug 8, 2003
    Reply to: MAVERICK

    Re: I need help locating a post

    Quote:
    MAVERICK said:
    Do you know if there is a conversion factor between torsional resonant frequency (Hz) and static torsional stiffness (Nm/degree)?




    No, I don't.

    It's surely more complicated than a simple conversion factor. There are a number of possible resonant modes: beaming, torsional, etc. The resonant frequency would be a result of mass as well as stiffness, so I don't think it can be a 1:1 relationship.
     
    Edit

    Forum

    1. All 

    Boards

     
    Board Subject Last post Rating Views Replies
    Porsche Sticky SUN'S LAST RUN TO WILSON, WY - 991 C2S CAB LIFE, END OF AN ERA (Part II) 4/17/24 7:16 AM
    GnilM     		774480 1798
    Porsche Sticky Welcome to Rennteam: Cars and Coffee... (photos) 4/7/24 11:48 AM
    Boxster Coupe GTS     		440134 565
    Porsche Sticky OFFICIAL: Cayman GT4 RS (2021) 5/12/23 12:11 PM
    W8MM     		261961 288
    Porsche Sticky OFFICIAL: Porsche 911 (992) GT3 RS - 2022 3/12/24 8:28 AM
    DJM48     		260237 323
    Porsche Sticky The new Macan: the first all-electric SUV from Porsche 1/30/24 9:18 AM
    RCA     		84794 45
    Porsche Sticky OFFICIAL: Taycan 2024 Facelift 3/15/24 1:23 PM
    CGX car nut     		5442 50
    Porsche The moment I've been waiting for... 2/1/24 7:01 PM
    Pilot
     
     
     
     
     
    		 879228 1364
    Porsche 992 GT3 7/23/23 7:01 PM
    Grant     		814003 3868
    Porsche Welcome to the new Taycan Forum! 2/10/24 4:43 PM
    nberry     		389659 1526
    Porsche GT4RS 4/21/24 11:50 AM
    mcdelaug     		388985 1454
    Others Tesla 2 the new thread 12/13/23 2:48 PM
    CGX car nut     		371233 2401
    Porsche Donor vehicle for Singer Vehicle Design 7/3/23 12:30 PM
    Porker     		367983 797
    Porsche Red Nipples 991.2 GT3 Touring on tour 4/11/24 12:32 PM
    Ferdie     		288422 668
    Porsche Collected my 997 GTS today 10/19/23 7:06 PM
    CGX car nut
     
     
     
     
     
    		 260979 812
    Lambo Huracán EVO STO 7/30/23 6:59 PM
    mcdelaug     		239502 346
    Lotus Lotus Emira 6/25/23 2:53 PM
    Enmanuel     		229665 101
    Others Corvette C8 10/16/23 3:24 PM
    Enmanuel     		220660 488
    Others Gordon Murray - T.50 11/22/23 10:27 AM
    mcdelaug     		168819 387
    Porsche Back to basics - 996 GT3 RS 6/11/23 5:13 PM
    CGX car nut     		140717 144
    BMW M 2024 BMW M3 CS Official Now 12/29/23 9:04 AM
    RCA     		117209 303
    Motor Sp. 2023 Formula One 12/19/23 5:38 AM
    WhoopsyM     		108387 685
    Others Valkyrie final design? 4/28/23 2:45 AM
    Rossi     		99562 219
    Porsche 2022 992 Safari Model 3/7/24 4:22 PM
    WhoopsyM     		84021 239
    AMG Mercedes-Benz W124 500E aka Porsche typ 2758 2/23/24 10:03 PM
    blueflame     		75009 297
    Porsche 992 GT3 RS 3/3/24 7:22 PM
    WhoopsyM     		53411 314
    Motor Sp. Porsche 963 3/16/24 9:27 PM
    WhoopsyM     		24926 237
    Ferrari Ferrari 296 GTB (830PS, Hybrid V6) 1/21/24 4:29 PM
    GT-Boy     		21143 103
    BMW M 2022 BMW M5 CS 4/8/24 1:43 PM
    Ferdie     		19436 140
    AMG G63 sold out 9/15/23 7:38 PM
    Nico997     		16564 120
    AMG [2022] Mercedes-AMG SL 4/23/24 1:24 PM
    RCA     		13572 225
    128 items found, displaying 1 to 30.