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Re: SVO - svo Digest - V01 #26

svo-request@SMARTWORX.COM wrote:
> svo Digest    Tue, 25 Nov 1997 00:00:47 -0500   V01 #26
> Today's topics:
>      'Cutting up an '85 SVO'
>      'SVO emblems'
>      'Road Trippin'
>      'Re: SVO:  Road Trippin'
>      'Re: SVO:  Road Trippin'
>      'Re: SVO:  Road Trippin'
> ----------------------------------------------------------------------
> Date: Sun, 23 Nov 1997 23:07:17 -0800 (PST)
> From: Monty Abbott <monty@loop.com>
> Subject: Cutting up an '85 SVO
> >I'm gonna cut the 85 up, add a tube frame front and rear clip and run it
> >in SCCA's new vintage class as an 84/85 Trans-Am/GTU car.
> No doubt you'll get lots of screaming at you for this, but it's your car so
> do what you want.  Beside all that work you want to do should make your
> 1.05g (skid pad) car be able to turn at least 1.10g.  And not only will it
> not make the car to terribly uncomfortable, but you'll even be able tell
> the difference in handling.
> NOTE TO ALL:  The mods I did to my SVO's suspension were to drop it 1.5"
> with progressive rate springs and put on all new Koni's.  The rear shocks
> are now the yellow Koni's.  I was hoping that this new springs (et.al.)
> wouldn't degrade the handling too much, but it did.  Much rougher than I
> wanted and I scrape bottom a lot too.  Yes, yes, yes the handling is
> flatter and sharper, but the dampening is just too harsh for the street.
> Think about it befor to take this well balanced cars too far.
> Monty
Hi Monty et al

the whole progressive rate spring deal is widely misunderstood....When
you lower any car significantly you must also increase the total
bum-rates of the vehicles suspension to provide adequate trravel control
at the reduced ride height...with a non-linear rate spring, or more
accurately, a rising rate spring, the intial rate is inadequately stiff
to sufficiently decelerate the heavy wheel and tire package,
particularly in combination with the enormous unsprung weight of the
stick axle.

Either increase bump-rates in shocks,
increase spring rates
or you will have travel problems....as counterintuitive as it may sound
increasing spring rate at a reduced ride height may well improve ride
quality by reducing the incidence of suspension bottoming.

PS lowering any MacPherson strut car without raising the lower control
arm pivot points and significantly increasing rollstiffness
(bars/springs) will always result in increased body roll due to reduced
roll center height.  CERTAINLY consider the physice behind chassis
changes before you make them..The SVO was a fairly well engineered
effort from the factiry considering the budget constraints. 

many seemingly benign changes have a cascade of side effects that are
not apparent until they rear their head.

PS we've got tons of used springs up at the shop for 10-20 bucks a
piece.  come on up on a weekend and dig through the stuff.. you'll
likely find a solution to your problems.