This all goes back to something I was trying to say the other night
(however, considering the horrid headache I had at the time, I don't
know if I made any sense or not).
Handling. What does it mean? Traction? Road feel? Passenger comfort?
I shall ramble now.
When it comes to autocrossing, and I go out into the garage with the
goal of improving "handling", I'm thinking that I want a car that
is well balanced with incredible turn-in. The goal is "just say no to
understeer", and respond steering wheel input before I even realize
I'm turning the wheel.
Ok, intro to control systems: in any given feedback system (say, a
high performance aircraft or a car's suspension) you sacrifice stability
for maneuverability. You know, the Popular Science blurb where the
FXYZ-2000 jet fighter has to have all these computers making course
corrections because the aircraft is so unstable. Why is it so unstable?
Because it can out-turn its own pilot.
The problem is your MG does't have a whole bunch of computers, so if you
want it to react the way I want mine to while autocrossing, it may be a bit
temperamental on the street. Not only does it respond faster to the
drivers inputs, it also responds faster to the changing road surface.
Since my car is also driven on the street, it is a compromise. It's not
so bad, but I do avoid potholes, and I wouldn't drive this one on dirt
roads like I used to.
Ok, now where I really wanted to go. Note that I've not said anything
about "traction", or, more specifically, the rear wheels breaking loose
under acceleration.
Of course this is going to be a big problem for me once the V-8 is in,
however, I would *never* attempt to solve such a problem by adding extra
weight.
Why?
Well, here goes. "I want to get up to speed fast, so I accelerate hard.
The rear tires break loose. Hmm, I'll add more weight and slow the car
down."
One of the TeamSanc cars is a Bertone/FIAT X1/9, running in D Stock.
On a fast course it is always slower with "just" the 150 pounds or so
that a passenger adds.
And, here's another problem, some basic physics that the Sport Ute in the
snow folks don't seem to understand.
The traction circle (which is actually oval, but that's another ramble
unto itself). A give tire can only provide so much grip. Yes, if you
put extra weight on the tire, you may be able to take off without
breaking traction. However, you still have to go around corners and
stop. All that extra weight means less cornering and stopping ability.
That's why wings and ground effects are so big in dreamland (Indy, F1,
WSC, GT1, etc): they add down force without adding weight! Seems like
those SUV types who think heavy 4wd means they can go anywhere still don't
understand when they jump on the brakes and the big ugly thing goes sliding.
Oh well, no one ever said people pay attention in high school physics.
All that said, I can honestly say I've never noticed a difference with the
spare in or out of the car. When autocrossing I remove everything from
the boot. Maybe I'm to focused to notice. Only "traction" problem I've
had with an empty boot was spinning in the wet on a decreasing radius.
-Keith Wheeler
Team Sanctuary http://www.TeamSanctuary.com/
Eric Erickson wrote:
>...
>are required (and *will* be going V8 plus sway bar). I believe the rear
>is fine but gave myself another fright yesterday when the back end
>suddenly felt extremely LOOSE and was bouncing all over the place. Hard
>cornering spun the inside wheel and was, basically, awful.
>
>Then I realised it... I had taken the spare wheel out to fit in a
>lawnmower I had hired for an afternoon and hadn't put the wheel back
>yet!
>
>What a HUGE difference there was with just that little bit of weight
>taken off the back end! Does anyone do any fine-tuning with sandbags???
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