Spridgets List Archive

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Mail From: Ron Soave <(email redacted)>

Keep going....


--- Mike Gigante <(email redacted)> wrote:
> The primary role of a panhard rod is transverse axle
> location. With
> standard suspension there is little to stop the
> entire wheel/banjo assembly
> from moving laterally under cornering load. There is
> enough bending and
> twisting of the springs (and for 1/2 elliptic the
> rear spring hangers) that
> the whole assembly can easily move > 1/2". the
> panhard rod prevents
> this lateral motion.
>
> The secondary role is to optionally modify the roll
> center of the rear
> suspension.
>
> This is a very brief discussion of what it means.
> For a better, more
> accurate,
> and more complete review see a book like Puhn's,
> Carroll Smith's, Van
> Valkenburg, or haney and Braun.
>
> The roll center of a spridget rear suspension (all
> solid axle suspensions)
> is the center of the "axle line". i.e. some 8-12
> inches off the ground
> depending on tyres. This is not ideal for high
> performance suspension. With
> a panhard rod, the roll center becomes the height
> of the panhard rod at the
> point it crosses the centerline of the car. This
> could be 0-5" below the
> standard
> roll center. The 5" max is a guess. Mine is about
> 3-4" below the axle line
> I think.
>
> By changing the roll center at the back you change
> the roll axis of the car
> and this in turn affects the cars tendency to
> understeer/oversteer.
>
> The roll of a sway bar is completely different. It's
> purpose is to reduce
> the
> amount of body roll. It does this by transferring
> load from one side of the
> car to the other. In doing so, it actually decreases
> the overall level of
> grip
> at that end of the car (all other things being
> equal). If you use a rear
> sway
> bar on a Spridget (without a LSD or locker) you'll
> just create lots of
> inside
> wheelspin and little real benefits.
>
> Interestingly, Spridgets see an increase in
> front-end grip by using a
> reasonably heavy sway bar. This is because all other
> things are *not*
> equal - the suspension geometry on a Spridget has
> very poor camber
> control which results in dramatically reduced grip
> with body roll,
> especially
> with nice fat modern radials. A sway bar at the
> front increases grip in this
> case because the greater loss of grip is via the
> horrible positive camber it
> prevents. As an aside this is another reason why
> static negative camber
> is so popular and effective on Spridgets.
>
> Note that most radials provide maximum cornering
> grip with some
> negative camber.
>
> If I rattle on any longer this will turn into an
> essay. Ask more specific
> questions
> if you like or go and borrow any of those books!
>
> Mike
>
> ----- Original Message -----
> From: <(email redacted)>
> To: <(email redacted)>
> Sent: Friday, 9 July 1999 2:21
> Subject: Re: Panhard rod question
>
>
> > In a message dated 7/7/99 6:18:15 PM Eastern
> Daylight Time,
> > (email redacted) writes:
> >
> > << What are the advantages of
> > the panhard rod anyway other than eliminating
> axle hop. Do they keep the
> > axle square on hard cornering also ?? >>
> >
> > - - - - - - - - - - - - - - - - - - - - - - -
> >
> > I'll let my ignorance show a bit here, but that's
> how we all learn. I'd
> like
> > to hear (read) an explanation of panhard rods
> also. What is the
> difference
> > between that and an anti-sway bar, and how does
> each work? Where is each
> > connected to the car.
> >
> > Some autocrossing is in the future of my Midget,
> if I ever get it on the
> road.
> >
> > Thanks,
> >
> > Allen Hefner
> > '77 Midget
> > '92 Mitsubishi Expo LRV Sport
> >
>
>

This read-only message was archived from a public mail list.
Mail From: (email redacted)

In a message dated 7/8/99 9:39:34 PM Eastern Daylight Time,
(email redacted) writes:

<< If I rattle on any longer this will turn into an essay. Ask more specific
questions if you like or go and borrow any of those books! >>

- - - - - - - - - - - - - - - - - - - - - - - -

Thank you very much, Mike, and all the others who answered my questions. I'm
sure that there are many lurkers out there who benefitted from it as much as
I. I have the "How to Power Tune Suspension" book, and I will dive into that
one.

It sounds like I will be looking for a panhard rod. And installation sounds
like it should be fairly straightforward. Once again, the combined wisdon of
"The List" comes through.

Allen Hefner
'77 Midget
'92 Mitsubishi Expo LRV Sport