For a guy on so many people's ignore list this is perversely gratifying. It's hard to know where to begin.
None of the posters actually understood what I wrote. I'm not sure if anyone understood what they thought I wrote. I have implemented a policy of never responding to wparsons as he is clearly an idiot, or so good at imitating an idiot no one can tell he's not really an idiot.
Most hilarious was the comment on Stig's lap in the 458. About the only places the Stig does allow a bit of oversteer is at the apex of hammerhead (logical, it's a tight bend and a transition bend, hence the name) and on the exit to hammerhead. All the remaining corners clearly show the 458 with the front wheels turned somewhat into the corner, as you would expect from an expert driver. I believe that's Ben Collins. I don't think many drivers in the world could beat Collins on that track although Rubens Barrichello did....
The engineer must know that mu is a constant by definition. He failed to note my qualifier when my little play on words caught him out. That's ok. His post at least confirms much of what I've been saying and with nifty charts. Thanks for the info, your text is not so useful and although your thesis is somewhat interesting and one can glean relevant information it isn't very helpful to the topics at hand. Engineers still avoid taking English at university except the mandatory course. Thanks anyway.
As for mu not being constant even though it is a constant this article goes some way to explaining my "oversimplification":
http://bsesrv214.bse.vt.edu/Hop/Pape...oefficient.pdf
I haven't read it but I have a pretty good idea what it does say.
I did like the perceptive if technically inaccurate suggestion that tire friction is non-Newtonian. It is true that tires don't behave strictly speaking as we might expect. Automotive engineers have not been troubled by the need to fudge the numbers a tad to match real world measurements though. It is perfectly correct that tire rubber meets the road surface in complex ways and also that considering mu to be constant as well as a constant means the actual performance of any given tire may be a bit different than the maths might predict but it is still obedient to Newtonian physics.
Use of the gravitational constant g isn't useful in analyzing oversteer relative to understeer because it is assumed to act through the imaginary CG. Use of g and fractions of g (which is actually absurd if one considers things properly) began with the aeronautics industry who do need to measure vertical g so it makes sense to use g for all accelerations in the pilot's 3D world. However, even there g is used for the entire vehicle and the entire pilot, not one end or the other. I'm pretty sure yaw, pitch or roll is neither measured nor displayed to the pilot in g, but I'm not a pilot.
Just as an amusing aside, a pilot or driver must fly by the sensations in his inner ear as compared to what he is seeing with his eyes. Neither pilots nor drivers can really "drive by the seat of their pants" that's all illusory. Without vision to coordinate with the acceleration your inner ear is experiencing you can neither drive nor fly. This is due to your inner monkey ....
I was particularly amused by the poster who suggested I get rid of understeer by pumping up my front tires and letting some air out of the rear tires...no, I won't be doing that.
I do note that Whiteline offers a 24 mm front bar (substantially stiffer than the stock 18 mm) which is really odd if much of what others have said about this car is correct. Please note that whiteline suggests this is your best bang for your buck:
http://www.whiteline.com.au/search_2011_4.php
I suspect they are right.
For my purposes I would consider fitting rear springs from the GT86 instead, if indeed the rest of the world gets a more softly sprung car than we do in North America. The gt86 apparently has softer rear springs than either the BRZ or the FRS but, squidgier front springs than the BRZ. In the wet softer rear springs should help but apparently not the gt86 as all testers report the gt86 is a real handful in the wet, as we have all discovered it is in the dry. No doubt that whiteline bar would be even more effective on a gt86.
Again, this is odd tuning if oversteer is faster.
I really was hoping for more reasoned posts. Just have to try again I guess. I'm patient and persistent.
Maybe somebody will actually quote a specific refutation from an actual suspension engineer? What an idea? We now apparently have one, or at least a wannabe one, but he still has difficulty reading and writing, and with a Masters degree (don't ask a practicing engineer what he thinks of engineers with masters degrees, just btw, they may suggest only incompetent engineers stay in school longer than they need to ...just sayin'. That's the basis for all those Howard jokes on Big Bang: no PhD AND "just" a Master's degree. All the engineers with only a bachelors degree roll on the floor laughing at that continual running double joke.)