At my last visit to the wind tunnel I was allowed to see the 7 Post rig in
operation. For those not familiar with what this is, here is a short
description. The car is supported by 7 high speed hydraulic servo cylinders,
one at each wheel plus 2 to the rear frame and one to the front frame. The
car is loaded with data aq equipment with each shock equipped with a strain
gage and a displacement transducer. Also ride height is measured front and
rear. They make several laps acquiring data. They can return back to the 7
post rig, plug the recorded data into the computer and simulate the exact
conditions they measured during the runs. It was kind of weird to see a
Winston Cup car moving around that much. Being naive to this I had to ask
why? Simple answer to obtain the best contact patch 100% of the time.
Anyone with data aq would be able to records this data as the installation
of the sensors was straight forward. They have developed a strain bridge
that replaces the eye mount on the shock and they measure travel parallel to
the shock. Let see what we got now force, distance, and time. Hmm sounds
like acceleration to me. Add in some wheel speed sensors and little
graphical interpolation and you might be able to decide on spring rates and
valving. Hey KT want to borrow some sensors?
Bill
----- Original Message -----
From: "Keith Turk" <kturk@ala.net>
To: "John Beckett" <saltracer@servusa.com>; "DrMayf" <drmayf@teknett.com>;
<land-speed@autox.team.net>
Sent: Saturday, October 11, 2003 4:27 PM
Subject: Re: Suspension
> John after our conversation about the Hondaliners roll under power I'm
glad
> he's added the Roll Bar.... I think the springs he's got in it are a bit
> soft... so that's the first tuning bit I'm going to do with the car.... I
> have to put some string in for this meet ( tied to the chassis and the
rear
> end ) to tell me how much it's moving... but ultimately my goal is to have
a
> transducer on each end of the car to measure travel...
>
> This meet should be really interesting to see how well the car behaves...
> I'm sure it's going to work well... that's not really in question... what
is
> up for grab's is how well it hooks up.... with solid suspension that
thing
> was a rocket ship.... this should make it even better.... which is really
> going to be a hoot...
>
> K
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