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Path: utzoo!watmath!clyde!burl!ulysses!allegra!alice!wookie
From: wookie@alice.UUCP (Keith Bauer   White Tiger Racing)
Newsgroups: net.auto
Subject: Re: Suspension systems
Message-ID: <2730@alice.UUCP>
Date: Thu, 26-Apr-84 09:54:58 EST
Article-I.D.: alice.2730
Posted: Thu Apr 26 09:54:58 1984
Date-Received: Fri, 27-Apr-84 04:27:28 EST
References: <7368@decwrl.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 58

Boy you really opened up a can of worms here!!  Suspension
design gets into some really heavy stuff (excellent for
computer types!  Let me know when you get some software
for this one!!)  There is an excellent book out by
Colin Campbell entitled "New Directions in Suspension
Design" or something to that effect.

Anyway what you basically want is to reduce unsprung weight
to the bare minimum ideally zero (I guess I should say
unsprung mass).  This is done by moving the brakes inboard
as on a Jaguar.  A nice place to see the ultimate
in modern suspension design is on a Formula race car such
as a Formula Ford.  On the new designs the springs, shocks,
brakes etc are all moved inboard leaving only the wheels,
spindle and control arms hanging out in the breeze.  Thus
the unsprung mass is about as minimum as you can get.

Also four wheel independent suspension is ideal so that the
actions at one wheel will not affect another.  To keep the
car from rolling in a turn antisway bars are added which
takes away from the independent suspension idea since it
ties the right and left sides together and stops independent
action and so you see suspensions must be a compromise of many
things.  Things you can do for your car are to reduce the
unsprung mass by getting lightweight alloy wheels (real
magnesium wheels like Minilites are great ......I can really
see the difference in my race car just between the
Minilites and aluminum wheels!).  If you want more expense
brakes parts can be substituted to reduce weight.  Adding
nice juicy roll bars will help keep the car flat on the
turns but you must experiment with front and rear bar sizes
to keep the handling as neutral as possible.  If you can
get some idea of the weight on each wheel and do some heavy
calculating you can determine what the spring rates and
shock absorber rates should be for your particular application.

I can go on and on so if you have further questions we'll
give it a try.

You noted that a big boat like a Cadillac rides
nicely.  If you would like to do a comparison go drive a full
size Cadillac like the Coupe De Ville (not a Fleetwood) and
compare the ride to a Chevrolet Impala.  The cars are essentially
the same in size and the suspension parts are identical on
both cars.  The Cadillac however is much heavier and so the
Sprung to unsprung weight ratio is much larger
on the Cadillac and so it rides better.  It won't corner however
because of its great mass.  So if you can get the same ratio
as the Cadillac but at the weight of the Impala you will have
a good compromise.  This of course applies to small cars
as well so look for suspensions with lightweight alloy parts
like the new Corvette and inboard brakes like the Jaguar and
lightweight like a racecar etc. etc.  Unfortunatly these
things are usually high tech and so are only on exotic cars
but yes they are out there and can be found!!

				Keith Bauer
				White Tiger Racing