Michael, you said:
"G-Whiz ... cannot compensate for elevation changes."
You're right, but it's even worse than that. Since it's connected rigidly
to the chassis, it can't compensate for lean in the corners and and squat
and dive when accelerating and braking. In a car with no suspension and
with rigid tires, this wouldn't matter. But in a real car, to get an
accurate measurement of lateral g's you'd need to mount the G-Whiz on a
gyro-stabilized platform that is level to mother earth at all times.
Notice when I said "accurate measurement", I mean getting the exact same
number of g's as you would with timed trips around a skidpad. You don't
really need an "accurate measurement" to compare two runs and see where
the differences were. You just need a "repeatable measurement", which is
doable if you don't change springs, tires, etc.
/Bill
--------- begin forwarded message -----------------
Date: Thu, 7 Mar 2002 11:59:22 -0800
From: "Michael R. Clements" <mrclem@telocity.com>
Subject: RE: Geez! (was: Going Downhill)
Skid pad is sustained Gs, not instantaneous peak. Usually measured on a 300'
diameter curve. I read a study somewhere that measured Kumhos, R1s and
Hoosiers with various sports cars and the highest sustained G they measured
was around 1.25. This would lead me to suspect that Borden's 1.47 is
probably a peak value -- however if it's sustained then I want a ride!
Also remember that since the G-Whiz is a two-axis accelerometer it cannot
compensate for elevation changes. So if you measure Gs while going up an
incline you will get higher readings. Based on experience with my own G-Tech
pro I can tell you that these things are HIGHLY affected by even slight
elevation changes (and bumps!).
> -----Original Message-----
> From: owner-ba-autox@autox.team.net
> [mailto:owner-ba-autox@autox.team.net]On Behalf Of james creasy
> Sent: Thursday, March 07, 2002 11:25 AM
> To: Darren Madams
> Cc: J C; ba-autox@autox.team.net
> Subject: Re: Geez! (was: Going Downhill)
>
>
> i think it also shows the max peak and sustained lateral, accel
> and braking
> G's. kinda cool as borden registered 1.47 lateral Gs (and 1 G braking and
> acceleration), and i think vic said he was getting 1.4 lateral on
> kumhos. i
> wonder how it compares to a skid pad G test.
>
> -james c
--------- begin forwarded message -----------------
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