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Re: Physics of Slaloms

To: cblome@yahoo.com
Subject: Re: Physics of Slaloms
From: GSMnow@aol.com
Date: Sun, 17 Oct 1999 03:22:55 EDT
Date: Fri, 15 Oct 1999 10:38:19 -0700 (PDT)
From: Craig Blome 

<<I've been trying to figure something out about slaloms
and getting myself confused.  All of the stuff on
course design I've seen (e.g. RHJ's notes) treat a
car's path though a slalom as a series of semicircular
arcs connected together, presumably with the car
traveling at a constant speed.   >>

<<SNIP>>

<<Reason I'm asking is, I'm attempting to work out a
physical explanation for whether a narrow car is
faster through a slalom than a wide one.  I know
empirically that tends to be true, but I'm thinking it
might not be solely due to the smaller side-to-side
distance traveled.  I tried using the semicircle
assumption and the math got WAY ugly. >>

A slalom or series of offsets is one place a narrower car will always have an 
advantage, as long as it can produce the same cornering G's.

When you reduce the distance you have to move from a straight line you travel 
a shorter distance, so even at the same speed it takes less time to complete. 
But then you also produce longer radius arcs so you can travel faster to 
produce the same cornering G's. This is a win win for the narrower car.

The biggest time in a slalom is the transition though, this is where the 
nimble car wins because it can achieve max G's faster and reverse the 
direction of max G's faster. Maybe some year I can make my highly modded STU 
83 Celica turbo transition like an HS 95 Celica ST (Oops ES)  I now own one 
of those too, and drove them back to back. I was 2.5 seconds faster in my STU 
beast, but still slower once you figure in the index difference. I would have 
scored about 200 more points on overall in the ST if I ran it in HS  ;-(

For some strange reason, the fastest cars I have driven in a slalom have all 
been front drive. Does anyone have a clue on that? My old GrandAm would 
slalom fast enough to slosh your brain. My 95 ST comes very close, if only it 
had some more power. My STU beast has me lifting to turn it and powering 
between cones. At least it launches between them, but it isn't pretty. I hope 
to get GEEZ plots in both cars soon. Several of our local guys got them, and 
I am ready to order one very soon. 

Gary M
STU turbo beast
HS (ES) slow but smooth

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