Re: Painting steering wheel etc.

["I.Mannix" <mannix@privatei.com>]

>At 10:25 PM 2/13/97 -0500, you wrote:
>>About the ride height thing, I'm an E stock autocrosser, so I'm always
>>looking for the best legal mods to stay in class.  I will say this:  lowering
>>an A1 or A2 more than one and a quarter inches will make your handling go to
>>shit!
>
>huh?? Well, for one, you cant lower your car (via lowering springs or cutting
>stock springs) and stay in E-stock.

Right you are!


>Secondly, I dont know how you conclude that lowering a car, (AKA the
>center of
>gravity) will make a car handle worse? My car sits 2" lower than stock and it
>has made my car at least 2 full seconds faster on most any track. Id like to
>hear your reasoning for the poorer performance.

I think what he's referring to is this - if you lower the car to the point
where the control arms are no longer parallel with the ground, but pointing
up to the front wheels, your roll center drops below the ground.  For those
that don't know, the roll center is the axis about which the car rotates -
with c-arms parallel to the ground, the roll center is roughly at pavement
level, slightly above.  Let's say the rc is ON the ground for discussion.
Now, let's say that the center of gravity (or mass, whatever) is at the
shift knob - umm, lets call it 18" off the ground (I'd guess it to be more,
but it works.)  ASCII crap to follow.


         STOCK (for discussion)

          cg    -----center of gravity is 18" above rc.

__/__rc__\____  angled slashes are tires, rc is roll center, "____" is ground



3" lowered

          cg

__/_____\_____  angled slashes again tire, "_____" still ground



         rc



OK, exaggerated a bit, but basically, the rc plummets when the c-arms are
pointed "up."  Problem is this - forces, basically, push against the cg in
corners.  The greater the distance between  the cg and rc, the longer lever
those evil, roll inducing forces have on your car.  So, even though the cg
has lowered 3" in relation to the pavement, the rc has dropped
significantly more than 3", essentially giving the evil forces of roll a
longer wrench - call it a breaker bar.


Also, when c-arms are pointed upwards, the fronts lose negative camber as
the wheel moves through its travel.  Not as significant, IMHO.


So, does your handling "go to shit?"  Not necessarily.  All things being
equal, well, yes.  If you lowered the car a bunch but still had soft
springs, the car would not be able to withstand the forces any better, and
the car would lean more/lose camber through body roll/do bad things.  If
you have stiffer springs, which resist the forces of cornering, not
necessarily.  A VW can be lowered a whole lot, and still handle right, IF
the springs are stiff enough.  Camber losses are negligable if springs
resist roll, but with ultra stiff springs, you wind up skipping over bumps.



Neuspeed's Race springs don't lower the car beyond this point.  Not sure
how much lower vs stock they are, but in my car, with nspeed Race springs,
the c-arms are mysteriously parallel (and the car is visibly lower than
most Rabbits - same goes for Sciroccos, from what I've seen).  Nspeed Race
springs are in the neighborhood of 300#/in - stiff, but not skipping over
bumps stiff.  It is possible to lower a VW a LOT and still work well - I've
seen it done.  General rule of thumb, though, look at the control arms -
parallel to the ground is good.  Pointed upwards significantly COULD be
bad.  Depends how the rest of the car is set up.



>
>>So, whether in racing or in lowering, get all the negative camber you
>>can, and forget about the nominal extra tire wear on the inside section of
>>the tread!

Negative camber in itself wont really wear  the insides that much - toe out
does it.  Lots of toe out combined with lots of camber will eat tires, but
not all that badly, IMHO - I run my autocross alignment all year long (cuz
we race all year long, even in Colorado), and it is not too bad if you keep
on top of rotational activities.  Toe out will make the car follow
grooves/ruts, but the turn in response is VERY much worth it;).  Much
better.


>
>In racing, you want as much negative camber as you can get and still be
>able to
>adjust the toe. You have to give and take when it comes to that, as Mr.
>Mannix
>described in his well written posting.

Well, thanks Shawn!  I appreciate it.  I just read your latest post while
writing this one, and I am basically reiterating what you said, but it is
true - lowering beyond 1 1/4" is not ALWAYS bad, but some thought has to go
into the rest of the suspension in order for it to work right.  All of the
above applies to Macpherson strut cars, VW in particular - double wishbone
is a whole other story.  Hondas can work when scraping the ground (but the
frictional losses must be huge!)


Au revior....Mannix


>
>
>
>Shawn
>--
>To subscribe or unsubscribe, send email to scirocco-l-request@privateI.com,
>with your request (subscribe, unsubscribe) in the BODY of the message.



--
To subscribe or unsubscribe, send email to scirocco-l-request@privateI.com,
with your request (subscribe, unsubscribe) in the BODY of the message.