Trying to Learn squat....

Discussion in 'Road Racing Forum' started by Mad Hatter, Feb 2, 2018.

  1. Mad Hatter

    Mad Hatter Gotta go Faster

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    Probably wiser to leave it as is. Maybe just wax the car.....

    I passed by the dyno we use too see a friend today. Saw a 2011 GT 500 that was with a stock suspension, The LCA was almost horizontal, I doubt that the lca was more then 2 degrees down to the axle.
     
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  2. 2012-Boss

    2012-Boss TMO Addict

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    I would corner balance the car if you have access to the scales / equipment.
     
  3. Grant 302

    Grant 302 OPM Spent: $328,347 Moderator

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    That's what I thought about the stock Boss LCA angle...until I took the measurement to the bolt centerlines.
     
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  4. Grant 302

    Grant 302 OPM Spent: $328,347 Moderator

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    Might help if you can also test some turns and see how much you can either goose/stab the throttle vs. roll into it. Results might surprise you. I think there's a lot of wisdom in some previous suggestions about learning to drive 'the fast way'.
     
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  5. Mad Hatter

    Mad Hatter Gotta go Faster

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    Yes, that explains why back when I installed the P springs, the car handled so oddly..... The original Boss LCA angle was already pointing down slightly (from the axle) to start with, and lowering it an inch more, made it go too far into roll under-steer.

    Currently its pointing up 1.6 degrees (Measured) after sorting out the rear ride heights. Bolts were at F. 6.3" and R. 5.7" Calculated angle is 1.9 degrees. This is all using the BMR brackets on the highest setting.

    Added benefit is the car is back at 55% front/45% rear. (and I don't have to worry about scraping the exhaust over the speed bumps).

    Off too wax the car and take it for a spin and see if I can notice any difference!
     
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  6. Grant 302

    Grant 302 OPM Spent: $328,347 Moderator

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    Agreed. Did the same mod on the GT with P springs on Boss shocks/struts and total grip suffered. Can't say I noticed it in any sense of roll steer conditions, but lateral grip was definitely missing.

    Looking forward to the results.
     
  7. Mad Hatter

    Mad Hatter Gotta go Faster

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    I could not get a feeling on the road, lots of traffic..... the car is very different with the spherical bushings and new UCA.... Feels solid (Yes, I know... I did lots of changes!)

    That and I have my track tune loaded without TC so I was a bit leery of pushing too hard on a public road. Will try to find a decent deserted road asap.
     
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  8. Grant 302

    Grant 302 OPM Spent: $328,347 Moderator

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    Took a bit of looking to find this, but in my opinion it supports what I've been saying:

    Antisquat Can Provide Added Traction, But Not In The Way We Might Think
    And this is what all those diagrams on the internet are missing! :eek:

    A brief resumé is below with some of his credentials:
    http://www.hotrod.com/contributors/bob-bolles/

    --------

    Also found this in the search. Forgive me @Norm Peterson, for quoting you 13+ years later form a different forum and discussion, but I thought it was interesting. My emphasis in bold.

    Anti-Squat and Autocrossing

     
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  9. Grant 302

    Grant 302 OPM Spent: $328,347 Moderator

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    Smart. Wouldn't want you to do anything unsafe!
     
  10. Mad Hatter

    Mad Hatter Gotta go Faster

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    Lol, the last off road adventure has left its mark I guess!!
     
  11. Grant 302

    Grant 302 OPM Spent: $328,347 Moderator

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    That's probably a good thing!
     
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  12. Norm Peterson

    Norm Peterson Corner Barstool Sitter

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    For starters, you need to at least fill in what is happening through the UCA. It's not sitting there doing nothing, and if the suspension squats at all the UCA will be developing some vertical force affecting that squat any time that it isn't perfectly horizontal in side view.

    Dynamic tire loading needs to be thought of in terms of time, specifically very short increments of time (milliseconds, not whole seconds). Anti-squat, or kinematic effects 'hit' first (almost instantaneously**), followed by shock effects (based on suspension velocity) and spring effects (suspension position). The timing of these three components matters at least some.

    **almost instantaneously because things like suspension bushing and tire compliances take time to happen.


    Norm
     
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  13. Norm Peterson

    Norm Peterson Corner Barstool Sitter

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    When more than one effect is involved, simplest is going to be a little more complex than when there is only one effect.


    Yes.

    And right about here is where this discussion needs to be framed in terms of 'load' and 'load transfer'.


    Norm
     
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  14. Norm Peterson

    Norm Peterson Corner Barstool Sitter

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    It's really just a different way to approach the same or a similar problem, and it's easier for some to work along this line of thinking (generally those with some engineering knowledge and experience) than trying to relate what taking a round out of the RR might mean.


    Norm
     
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  15. Norm Peterson

    Norm Peterson Corner Barstool Sitter

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    Agreed that circle track racers tend to not get the respect they deserve.

    The problem seems to come in trying to translate back and forth between "practical hands-on circle track" and "engineering" so that everybody gets to be on the same page.


    Norm
     
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  16. Mad Hatter

    Mad Hatter Gotta go Faster

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    I am open to try anything reasonable, that makes some sense. in the effort to go fast.... the Phoenix cars and other like them have long impressed me with the spectacular results they get, so I will give a go at trying out the recipe as best I can. Always good to have a heated debate over how to get to a goal. At the very least to make you go over the process again and again and see what can be improved upon.
     
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  17. Norm Peterson

    Norm Peterson Corner Barstool Sitter

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    I was specifically responding to the picture, which wasn't showing any UCAs at all and does suggest that only the LCAs are responsible. People tend to have an easier time with pictures than text for things like this.

    [​IMG]



    Hence my later comment on the matter of translating between thinking based on practical experience and thinking from a solid understanding of the engineering principles involved. We don't all think the same way, and I've seen this all the way down to the autocross and performance-street levels. Even Ron Sutton, Bob Bolles, and Mark Ortiz don't see everything in exactly the same way.


    Norm
     
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  18. Mad Hatter

    Mad Hatter Gotta go Faster

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    That diagram was unclear to me for a long time, I used it to set up my car and ended up with a instant center way back in the car. Which is my fault I know.... I ignored the UCA for a long time.
     
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  19. blacksheep-1

    blacksheep-1 TMO Addict

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    Call me stupid, but I can't tell you how many times I bought popsicle sticks and pins and cardboard, then made models of suspensions to try an figure them out. Unfortunately, being old school, I have to "see" what is going on.
     
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  20. Grant 302

    Grant 302 OPM Spent: $328,347 Moderator

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    Nothing wrong with that. A drawn model or a physical model. I use them both. Pencils, pens, boxes, paperclips...all help visualize and confirm what can be drawn on a diagram and vice-versa.

    EDIT:
    You and Phoenix have done a lot of testing and validation of your setup on track. That's good enough for me! Even if you can't share the details, you've certainly given us something interesting to discuss. :D
     
    Last edited: Feb 14, 2018
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