[V8] track F/R and fun stuff.....:-)

[J123fs at aol.com]

Dave, Scott, Al and all.....
 
I too am following with interest, and don't see a pissing match -- just  the 
airing of opinions to uncover the facts
 
I guess leaving the computer idle for a day due to the power outage here  has 
lit some fires. Sorry.
But, I will say a good discussion even if has conflicting opinions or  
interpretations of the facts is no the less enlightening and entertaining if  kept 
in the perspective of having fun with our minds and cars, right? I  personally 
was not trying to bust anyone's chops, just giving the benefit of my  
experience and knowledge, and good suspension design software, along with what I  have 
seen/ and put to use with some of the other more experienced  racers here in 
good ol' stormy NE.  


This is - and can be very cool to all who follow the thread who 'might'  what 
to figure out what can really work on their cars. 
 
Some of my observations are:
 
I think myself and others want to try to explain why some things  people 
think don't matter when talking about lowering their car, or adding  track, or 
wheel offset (notice how I made the distinction?) DOES matter in  the grand 
scheme when trying to dial in the handling of a very front heavy car.  You change 
one thing without understanding how it changes the "big picture" and  you lose 
ground handling wise - which is a simple way of saying making the car  handle 
worse, or more unpredictably. Scott is on the money with his observations  and 
knowledge- and I see where he is getting frustrated. I too felt that  way 
reading some of the postings. And I'm not just trying to get a dig in  
here.....this can be fun you know! 
 
 PS:  bump steer matters far more on a race  track  (I've yet to see an 
aftermarket modification to tune the bumpsteer  on the wife's odyssey)

 
I disagree here strongly...It matters, period. Race track or street.
If you lower the car from stock it matters, as the designed geometry no  
longer mesh. 
Let me explain;  The steering rack and the front suspension are  mounted in 
different planes (ie:height), and both articulate in arcs from the  terminus of 
the inner tie rod (really just a bushing) and control arm mounting  point on 
the subframe respectively. They both move in arcs from their mounting  
points.....follow me? Because they are at different mounting points those arcs  they 
travel in are NOT the same. When the car gets lower you start to pull the  tie 
rod in as the wheel uses up it's travel and it affects the toe in (or out  
depending on the mounting point of the rack in relation the c-arm) or out of the 
 wheel. That IS BUMPSTEER. Throw in turning the wheels in a slow corner and 
you  throw in castor changes and you have mess. This = Unpredictable handling. 
Most  cars only have a limited range of motion in articulation and when you 
exceeded  it by lowering the car too much this also causes bumpsteer as the 
steering rack  runs out of travel at it's "full droop" or extension and it stops 
correcting the  steering angle of the wheel at it's limits- NOT GOOD.
 
And as Scott describes it, the sucky front suspension geometry is  familiar 
to me and can be worked around. 
 
Jack's contribution has been worth my study, even if I'm not sure it  applies 
to non-rwd chassis 100%.
 
Scott is correct though, The type 44 suspension is  marginal from the 
standpoint of handling- it was designed for ride  quality and isolation from the 
people in the car the road vibrations, feedback,  ect....not to get the best 
handling. And yes, it can be worked around.....no  doubt. There is soooo much slop 
up there to deal with as a great starting point  to correcting the handling it 
begs for me to tell my experiences with solid  subframe bushings- but I 
digress. One the second point I  myself seem to get frustrated when people do not 
realize that is  doesn't matter FWD, FourWD, RWD when it comes how a suspension 
works- and where  or how you are trying to make more, less or the same grip- 
Front or  Rear- the laws of physics are the same, and how something moves  
geometrically remains the same. The theories- or better stated- accepted  
practices apply no matter what kind of car suspension it is on, or which end of  the 
car. Period. 
How those laws and practices are applied is the rub. Scott puts  it 
perfectly. 
 
Too many of you hear what you want to hear, rather that what I'm  typing. 
 
One person I talked at much length about track F/R on STILL does not  seem to 
understand what I was saying- Maybe I did a crappy job explaining- I do  not 
know. But, he stubbornly sticks to his guns dismissing what I know  as fact- 
only to argue anecdotal and subjective opinion rather than backing it  up with 
facts- and it's tough to have a good two way discussion if the point  your 
arguing is only your opinion, and not backed by facts.  


Maybe it's time to put this thread to bed, like myself right now- all the  
midnight oil is gone! :-) (12:08 am)
 
Jack
 







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