Deflating Question





Results 1 to 15 of 15
  1. #1
    Join Date
    May 2009
    Location
    Ruimsig
    Age
    56
    Posts
    4,617
    Thanked: 6377

    Default Deflating Question

    Does this mean running Grabber AT3s at 2.4 bar is the same as running Scorpion ATRs at 1.2 bar?

    Asking for a friend


    ;-)


    Name:  20200125_111649.jpg
Views: 435
Size:  35.4 KB
    Estee = S T = Sean Towlson

    There is no such thing as inclement weather, only poor selection of clothing.... or Vehicle

    2010 Hummer H3 5.3lt V8, 300 HP, FDL, RDL, CDL, TC and 4:1 Low Range Building for Touring, not Trails

    FJ: One day when I am big

    Land Rovers: Done unfortunately

  2. #2
    Join Date
    Nov 2010
    Location
    Phalaborwa
    Age
    32
    Posts
    18
    Thanked: 4

    Default Re: Deflating Question

    Look that way on the chart

  3. #3
    Join Date
    Apr 2018
    Location
    Fraserburg
    Age
    60
    Posts
    699
    Thanked: 648

    Default Re: Deflating Question

    At the bottom it says all the tyres are at 0.8 bar.

    The entire chart is giving me insufficient or ambiguous info too:

    1. What does the FP in bold at the top stand for?
    2. What unit is the footprint expressed in? Length or square centimeters? It says length but that is no use if the tyre is wider or narrower. Footprint should be in area, not length.
    3. Where is the inflation pressure stated regarding your original question?
    Last edited by Olyfboer; 2020/01/25 at 02:53 PM.
    2001 Isuzu Frontier 4X4 DT280 LX 2.8 Turbo Diesel (Tourer)
    2011 JMC 4X4 Double Cab 2.8 Turbo Diesel (Work Bakkie)
    1973 Land Rover Series 2A 109" Ford V6 Kanniedood, Salisbury diff, galvanised chassis etc. (Hobby and Work vehicle)

  4. #4
    Join Date
    Jun 2009
    Location
    Barberton
    Age
    62
    Posts
    5,767
    Thanked: 1069

    Default Re: Deflating Question

    Quote Originally Posted by Olyfboer View Post
    At the bottom it says all the tyres are at 0.8 bar.
    Nope,
    They used different pressures, and each column represents one of those pressure settings. The footnote says that the column for the 0.8 bar was used to sort the list. An error in that footnote is the part where they say from small to large, when their sorting is from large to small.
    Last edited by RoelfleRoux; 2020/01/25 at 06:01 PM.

  5. #5
    Join Date
    May 2009
    Location
    Ruimsig
    Age
    56
    Posts
    4,617
    Thanked: 6377

    Default Re: Deflating Question

    The FP columns state the pressure for each test. So the first FP column is 2.4 bar.

    The value is derived from using 2x set squares and is stated in cm.

    Another test SA4x4 did, in the same article, tested the actual footprint by taking a print of each tyre at the test pressures on a piece of paper.
    Estee = S T = Sean Towlson

    There is no such thing as inclement weather, only poor selection of clothing.... or Vehicle

    2010 Hummer H3 5.3lt V8, 300 HP, FDL, RDL, CDL, TC and 4:1 Low Range Building for Touring, not Trails

    FJ: One day when I am big

    Land Rovers: Done unfortunately

  6. #6
    Join Date
    May 2009
    Location
    Ruimsig
    Age
    56
    Posts
    4,617
    Thanked: 6377

    Default Re: Deflating Question

    Quote Originally Posted by RoelfleRoux View Post
    Nope,
    They used different pressures, and each column represents one of those pressure settings. The footnote says that the column for the 0.8 bar was used to sort the list. An error in that footnote is the part where they say from small to large, when their sorting is from large to small.
    Indeed. The error reverses the ranking
    Estee = S T = Sean Towlson

    There is no such thing as inclement weather, only poor selection of clothing.... or Vehicle

    2010 Hummer H3 5.3lt V8, 300 HP, FDL, RDL, CDL, TC and 4:1 Low Range Building for Touring, not Trails

    FJ: One day when I am big

    Land Rovers: Done unfortunately

  7. #7
    Join Date
    Apr 2018
    Location
    Fraserburg
    Age
    60
    Posts
    699
    Thanked: 648

    Default Re: Deflating Question

    Quote Originally Posted by RoelfleRoux View Post
    Nope,
    They used different pressures, and each column represents one of those pressure settings. The footnote says that the column for the 0.8 bar was used to sort the list. An error in that footnote is the part where they say from small to large, when their sorting is from large to small.
    Thanks. This shows exactly why any text has to be completely unambiguous. Something I strove for my entire professional life writing technical documents, risk analysis and root cause analysis. Not all people read things the way it's intended. Especially people like me that regularly think "outside the box".

    Estee, I will redo my thinking tomorrow with the new information in mind and see what answer I get. What does FP stand for anyway? Footprint Pressure?
    2001 Isuzu Frontier 4X4 DT280 LX 2.8 Turbo Diesel (Tourer)
    2011 JMC 4X4 Double Cab 2.8 Turbo Diesel (Work Bakkie)
    1973 Land Rover Series 2A 109" Ford V6 Kanniedood, Salisbury diff, galvanised chassis etc. (Hobby and Work vehicle)

  8. #8
    Join Date
    May 2009
    Location
    Ruimsig
    Age
    56
    Posts
    4,617
    Thanked: 6377

    Default Re: Deflating Question

    I am not sure so assuming it could be Footprint as this table is under the section 'Footprint Length'.

    The sidewall table uses SDWL for the column headers in the section; 'Sidewall Bulge'.
    Estee = S T = Sean Towlson

    There is no such thing as inclement weather, only poor selection of clothing.... or Vehicle

    2010 Hummer H3 5.3lt V8, 300 HP, FDL, RDL, CDL, TC and 4:1 Low Range Building for Touring, not Trails

    FJ: One day when I am big

    Land Rovers: Done unfortunately

  9. #9
    Join Date
    Apr 2018
    Location
    Fraserburg
    Age
    60
    Posts
    699
    Thanked: 648

    Default Re: Deflating Question

    Thanks Estee.

    Then I have to assume your original assumption is correct but may be wrong due to insufficient information. Acronyms can be frustrating when there is no list and unapproved acronyms creep in. On one such job I got a radio message -

    Control - "Interrogative location?"
    Me - " Approaching the Bravo Yankee Tango."
    Control - (After several seconds) "The Bravo Yankee Tango?"
    Me - "Affirmative."
    Control - "Interrogative Bravo Yankee Tango?"
    Me - "The Big Yellow Thing."
    Silence.
    And they brought out an approved acronyms list after that.

    In the military when someone sent a lot of acronyms in a signal message, he could get one back from his superiors with a single acronym on it - HOMKA. It's an acronym for Hou Op Met K@k Afkortings.
    2001 Isuzu Frontier 4X4 DT280 LX 2.8 Turbo Diesel (Tourer)
    2011 JMC 4X4 Double Cab 2.8 Turbo Diesel (Work Bakkie)
    1973 Land Rover Series 2A 109" Ford V6 Kanniedood, Salisbury diff, galvanised chassis etc. (Hobby and Work vehicle)

  10. #10
    Join Date
    May 2009
    Location
    Ruimsig
    Age
    56
    Posts
    4,617
    Thanked: 6377

    Default Re: Deflating Question

    I have updated the info here with more tables but alas Olyf, I fear some ambiguity might remain in the column headers.

    https://www.4x4community.co.za/forum...01#post4313601
    Estee = S T = Sean Towlson

    There is no such thing as inclement weather, only poor selection of clothing.... or Vehicle

    2010 Hummer H3 5.3lt V8, 300 HP, FDL, RDL, CDL, TC and 4:1 Low Range Building for Touring, not Trails

    FJ: One day when I am big

    Land Rovers: Done unfortunately

  11. #11
    Join Date
    Jul 2011
    Location
    Randpark Ridge
    Age
    52
    Posts
    2,402
    Thanked: 251

    Default Re: Deflating Question

    I don't trust all their figures.

    How can the RF10 AT go from a footprint of 32 at 1.2 bar down to 29 at 0.8 bar
    Discovery 3 TDV6 S G4 No 29 - Mine
    Discovery 4 TDV6 SE - SWAMBO's

  12. #12
    Join Date
    May 2009
    Location
    Ruimsig
    Age
    56
    Posts
    4,617
    Thanked: 6377

    Default Re: Deflating Question

    Quote Originally Posted by rabbiddog View Post
    I don't trust all their figures.

    How can the RF10 AT go from a footprint of 32 at 1.2 bar down to 29 at 0.8 bar
    The answer could lie in the correlation tables I published in the selection thread. There is a fairly strong negative relationship between 0.80 Bar and sidewall comstruction of -0.5. This is higher than the other pressures recorded.
    Estee = S T = Sean Towlson

    There is no such thing as inclement weather, only poor selection of clothing.... or Vehicle

    2010 Hummer H3 5.3lt V8, 300 HP, FDL, RDL, CDL, TC and 4:1 Low Range Building for Touring, not Trails

    FJ: One day when I am big

    Land Rovers: Done unfortunately

  13. #13
    Join Date
    Sep 2018
    Location
    Not too far from Pofadder
    Posts
    579
    Thanked: 358

    Default Re: Deflating Question

    What size tyre is this table for?

  14. #14
    Join Date
    May 2009
    Location
    Ruimsig
    Age
    56
    Posts
    4,617
    Thanked: 6377

    Default Re: Deflating Question

    Quote Originally Posted by Bex View Post
    What size tyre is this table for?
    I would need to check the article Bex. It does state the size
    Estee = S T = Sean Towlson

    There is no such thing as inclement weather, only poor selection of clothing.... or Vehicle

    2010 Hummer H3 5.3lt V8, 300 HP, FDL, RDL, CDL, TC and 4:1 Low Range Building for Touring, not Trails

    FJ: One day when I am big

    Land Rovers: Done unfortunately

  15. #15
    Join Date
    Jul 2011
    Location
    Randpark Ridge
    Age
    52
    Posts
    2,402
    Thanked: 251

    Default Re: Deflating Question

    I see the updated footprints on the other thread look much better.

    Some things just didn't make sense.
    Discovery 3 TDV6 S G4 No 29 - Mine
    Discovery 4 TDV6 SE - SWAMBO's

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •