Charles,
The Ackerman is measured through the center of the TRE and the king pin and
then both those lines meet somewhere close to the center of the diff,
depending what % of Ackerman the car has. Changing the rack position doesn't
change those lines so the Ackerman stays the same, but it does change the
toe-out on turns.
Thanks
Barry Spencer - Owner
Spencer's Motorsports
----- Original Message -----
From: "Charles Cox" <charles@coastalbay.com>
To: "ba-autox" <ba-autox@autox.team.net>
Cc: <james@thevenom.net>
Sent: Wednesday, January 08, 2003 2:15 PM
Subject: Ackerman
> Actually moving the rack will change the Ackerman as will toe and other
> alignment changes. They are two separate things but are inter-related. If
it
> could be done, properly setup Ackerman steering would align the king-pin
> centerline with the steering arm to tie-rod end connection with the
> centerline of the rear axle. Unfortunately, there are many variables that
> change this effect some of which include king pin angle, height and
location
> of steering rack, height and angle of steering arm, etc. You also need to
> consider bump-steer, roll-steer, roll-couple among other things.
>
> Charles
> mailto:charles@coastalbay.com
>
>
> ----- Original Message -----
> From: "Barry Spencer" <bspencer@tsoft.com>
> To: "James Creasy" <james@thevenom.net>; <ba-autox@autox.team.net>
> Sent: Wednesday, January 08, 2003 12:28 PM
>
>
>
> > Hi James,
> >
> > Ackerman and toe-out on turns are two seperate things. Changing the rack
> > position won't change the ackerman, but it will change the toe-out on
> turns.
> > On custom made/kit cars you need to measure the toe-out on turns, for
> > example if you turn your steering wheel half a turn on an average autox
> > course, measure what toe-out on turns you have at that point, don't
forget
> > to add your static toe setting to that amount. Let me know what that
> > measurment is and let's go from there.
> >
> > Thanks
> >
> > Barry
> >
> >
> >
> > ----- Original Message -----
> > From: "James Creasy" <james@thevenom.net>
> > To: <ba-autox@autox.team.net>
> > Sent: Wednesday, January 08, 2003 11:11 AM
> > Subject: ackermann tuning for autox?
> >
> >
> > > i know ive asked this before, but here i am again...
> > >
> > > i am right in the middle of changing the position of my steering rack
to
> > put
> > > more ackermann in my car. i think it changes it from about -100%
> > ackermann
> > > to +30%. however ive got no clear idea of how to determine how much i
> > > should have. i know it has been debated for years, but modern tire
> > > composition might warrant higher amounts of it.
> > >
> > > will anyone else that has set up this give me any hints? what should
i
> > look
> > > for in tire temps, etc. (this is with dot-r tires. )
> > >
> > > the bonus question is what about my car might make it have an unusual
> > > affinity for hoosiers- a good two seconds faster than on kumhos (on
> > > concrete). or are kumhos just that much worse on concrete but not so
> > > different on asphalt?
> > >
> > > thanks,
> > >
> > > -james
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