derBayerische May/June 2022 - 30

T H O U G H T S F R O M A N H P D E S U S P E N S I O N C L I N I C
■ (From the Left) An E36 lifts a wheel during NCC's club race. Another E36 leading the pack and lifting a wheel. Photos by FormerInstants.com.
1) get stiffer / shorter springs 2) get bigger (stiffer) sway bars 3) get camber
plates or camber bolts. Shock absorbers have the least effect and are for finetuning
your setup.
Stiffer springs will help reduce body roll during
cornering, reduce squat during acceleration, and
reduce dive when braking. Get a matched set (front &
rear). However, stiffer springs will make the car's
overall ride stiffer. Also, a stiffer suspension is less
compliant on a bumpy track, and may actually reduce
tire contact with the pavement when going over those
bumps. There's always a tradeoff.
Bigger anti-sway bars reduce body roll during
cornering by connecting the left and right sides of the
suspension to each other. We should really call them
anti-roll bars, because that's what they do. Anti-roll
bars reduce body roll without making the car's overall
ride feel harsher. During cornering, the springs and
shocks on the outside of the corner compress, and the
springs and shocks on the inside of the corner extend.
Compressing one side and extending the other side
results in a twisting force being applied to the anti-roll
bar, due to its lever-like shape, which is somewhat like a bicycle's handlebars.
(See the diagram.) The shape of the anti-roll bar is such that it resists being
twisted, that is, it resists letting one side extend while the other side compresses,
so it helps reduce body roll and keeps the car flatter during cornering.
The thicker the bar, the greater the resistance to being twisted.
Keeping the car flatter during cornering maximizes the tires' contact patch
against the pavement. Maximizing the tires' contact patch maximizes grip , and
maximizing grip maximizes the speed (the lateral
g-forces) at which the car can corner.
I prefer hollow, adjustable anti-roll bars because
they're lighter than solid bars but almost as strong, and
the adjustability means I can experiment with the soft,
medium, and hard settings.
HOWEVER, a bigger front anti-roll bar (without
■ Speed Academy explains how sway bars
work: As the suspension travels upward on
one side, the anti-roll bar twists along its length
and provides torsional resistance, since it
is effectively anchored to the suspension
components on the other side.
a matching rear bar) tends to increase the car's understeer.
A bigger rear anti-roll bar (without a matching
front bar) tends to increase the car's oversteer. Since
front-wheel-drive and all-wheel-drive cars tend to
understeer, a bigger rear bar can help. Think twice
though before using a bigger front bar on a car that
already understeers; it'll make the understeer worse.
For autocrossers competing in the " Street "
class, note that you can only change one anti-roll
bar, front or rear, but not both. For the autocross
" Street " class, also note that you can upgrade your
shock absorbers but not your springs. Adjustable camber plates or camber
bolts are not allowed.
If your car is not in the autocross " Street " class, then camber plates or
camber bolts on the front suspension make it possible to set more negative
■ (From the Left) A club racer lifts a wheel at turn 3 on the Summit Point Main. Leaning into the suspension at turn 3 during NCC's October HPDE.
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derBayerische May/June 2022

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