- Basic Suspension Tuning -
With Mark Pavidis
 Mark
  Pavidis is old school. He’s been making A-mains at big races since some
  of today’s younger pro racers were in diapers. He has raced for some of
  the biggest companies in our industry, and has helped developed some of
  the most influential chassis, tire, and component designs in the RC world.
  Mark has been competitive at the top levels of RC racing longer than
  anyone from any part of the world, and many racers from any generation
  regard him as one of the toughest competitors they’ve ever faced.
Mark
  Pavidis is old school. He’s been making A-mains at big races since some
  of today’s younger pro racers were in diapers. He has raced for some of
  the biggest companies in our industry, and has helped developed some of
  the most influential chassis, tire, and component designs in the RC world.
  Mark has been competitive at the top levels of RC racing longer than
  anyone from any part of the world, and many racers from any generation
  regard him as one of the toughest competitors they’ve ever faced.
  
He has won U.S. National
  championships in several classes, including 1/8-Scale Buggy. Along with
  Japanese legend Masami Hirosaka, Mark is the only other driver to win
  IFMAR World titles in both on-road and off-road competition. Unlike
  Masami, or any other driver, Mark is the only driver ever to win IFMAR
  World championships in both electric and nitro competitions. His 2006
  IFMAR 1/8-Scale Off-Road title reaffirmed his place in RC history as one
  of the best racers of all time.
  
I sat down with Mark at
  AKA’s new offices in Murrieta, California, to discuss the most common
  adjustments available on today’s nitro buggies. When Mark Pavidis talks
  buggy setup, we listen.
   CAMBER
CAMBER
  Camber is the relationship of the tire to the ground, such that a tire
  that is perpendicular to the racing surface has zero camber. If the top of
  the tire leans in toward the car, it has negative camber; likewise, a tire
  that leans outward at the top has positive camber.
  
Front Camber. Adding more
  negative camber to the front of your buggy will make your car less
  aggressive, especially when turning into the corner. More negative camber
  will also lessen the chances that the front tires will catch on ruts or
  bumps. Mark says, “On rough or high speed tracks, adding more negative
  camber is an important adjustment to make.” It’s usually best to start
  with a little bit of negative camber in the front.
  
Taking away negative camber
  (or even adding positive camber) to the front of your buggy takes away a
  little bit of overall steering, but will make your buggy steer into the
  corner more aggressively since the corner of the tire will dig into the
  track’s surface. This can help on slower tracks with plenty of
  high-speed corners.
  
Rear Camber. More negative
  camber in the rear tires will free up the rear of the car, making it whip
  around by taking away lateral traction. As with the front of the car, more
  negative camber will help your buggy navigate through rough sections of
  the track.
  
Running less negative camber
  in the rear will take away a little bit of overall steering, but your
  buggy will handle more responsively. If the track is not bumpy and has
  good traction, try running less negative camber to help carry more speed
  through corners.
   CAMBER
  LINK POSITIONS
CAMBER
  LINK POSITIONS
  The optional camber link mounting holes alter the rate at which the camber
  angle changes throughout the suspension’s movement. For the purposes of
  making only the following changes, you should reset your camber angles
  after moving the camber link locations.
  
Front
  Outside (on the front hub).
  A longer link means the camber will change less as the suspension
  compresses, which will make the car turn in harder but push exiting the
  corner.
  Moving to the inside hole will give more camber rise, which smooths out
  initial turn-in but adds steering through the middle and exit of the
  corner.
  
Inside (on the shock tower).
  Raising the inner mount will keep the front end more flat. On high bite
  and smooth track, this will smooth out your car’s steering response and
  make it easier to drive.
  Lowering the inner mount will add body roll and make the car more
  aggressive. Mark almost always runs the lowest hole available.
  
Rear
  Outside (on the rear hub).
  A longer link gives less camber rise, which means less traction. On a high
  speed track with high grip, this will add more support by eliminating body
  roll.
  A shorter link equals more camber rise and more traction. Because a
  shorter link will make the rear of the car feel softer, it will better
  handle rough sections of the track.
  
Inside (on the shock tower).
  Moving the inner camber link mount to the inside or outside hole will have
  the same effect as changing the length of the link on the hub.
  Raising the link on the rear shock tower will keep the buggy flat through
  corners and have less camber rise; this is a good adjustment to make on a
  smooth track with high traction.
  Lowering the link will add camber rise and make the car more forgiving
  when the track is rough.
  Moving the link out on both the shock tower and the hub, which will keep
  the camber link the same length, will add support and make the rear of the
  car feel stiffer.
   TOE-IN
  / TOE-OUT
TOE-IN
  / TOE-OUT
  This is the angle of the tires when compared to the centerline of the car.
  A tire that has zero toe is pointing straight ahead. Toe-in means that the
  tires point in toward each other, while toe-out is the opposite.
  Front Toe
  1/8-Scale Buggies almost always run toe-out in the front. Adding more
  toe-out will make the car smoother and easier to drive on big tracks, as
  well as increase low-speed steering by decreasing the car’s turning
  radius.
  Likewise, decreasing toe-out (even to the point of running zero toe) will
  give the car more initial steering response. This is usually only done on
  tight, low-speed tracks.
  Mark says, “If you run toe-in (at the front), your car won’t come out
  of the corner very well, and initial turn-in will be too darty. If you run
  toe-out, it will turn in and come out of the corner much smoother.”
  Rear Toe
  The rear of the car is much different, as toe-out is never used. Adding
  more rear toe-in will add overall rear traction, both in a straight line
  and during cornering.
  On the flip side, less toe-in will increase steering since the rear tires
  will have less traction. Also, the rear suspension and driveshafts will be
  at less of an angle, which will help on rough sections of the track.
  Mark says, “Nine times out of ten, I run maximum rear toe-in (on the
  Kyosho MP9, this is three degrees of toe-in per side). The only time I run
  less is in truggy, because there’s already so much grip.” Also, he
  suggests only changing the inner pivot blocks to adjust toe-in rather than
  using rear hubs with different angles of toe-in. Changing the rear hubs
  will increase the angle of the driveshaft joint and change how the car
  works.
  KICK-UP
  Kick-up is the angle between the ground and the lower inner hinge pins on
  which the suspension arms swing. Altering kick-up will affect the car much
  like caster does. In addition, adding kick-up will make your bump higher
  and further. You should only consider decreasing kick-up when the track
  has few or no jumps.
  
   SHOCK POSITION
SHOCK POSITION
Tower. Moving the shock in on the tower will make the shock feel
more progressive i.e.; initially it will feel softer, but increasing
in stiffness as the shock compresses. If the track is slippery, move
the shock in on the tower to add body roll and overall traction.
Moving the shock outward will make the shock feel more linear. This
will free up the car and make it jump much better. On a track with
lots of grip, move your shocks out on the tower to reduce body roll.
Arm. Moving to a more
inward shock location on the arm will make the buggy feel softer and
less stable. For blown out tracks, this adjustment will help
navigate bumps and ruts without hurting the car’s jumping
performance as much as moving the shock inward on the tower.
An outer shock position on the arm will make the car rotate more
during cornering, and make the buggy feel more stable. This comes at
the expense of rough track performance.
SHOCKS
Shock Oil. Thicker shock oil will help the car to navigate larger
jumps and bumps since the oil will slow the reaction of the shock.
In hot weather, increase the weight of your shock oil to maintain
the same damping characteristics.
Thinner shock oil will allow the shock to react more quickly, and
help your buggy soak up smaller bumps and track imperfections. If
your buggy works well in warm weather, switch to thinner shock oil
in very cold conditions.
Mark explains, “Temperature is a huge part of choosing shock
oil.”
Shock Pistons. Choosing
the correct shock pistons is quite simple. On smooth tracks with big
jumps, Mark suggests using smaller pistons to slow down the shock
action. On rough tracks with fewer jumps, reach for pistons with
larger holes to allow the shock to soak up the ruts.
Shock Springs. Mark
doesn’t often change his shock springs to adjust his car. In fact,
he suggests changing both the front and rear springs at the same
time to maintain the same balance front to rear. If the track
surface is slippery, go to lighter springs to create more body roll
and slow the car’s reactions. On asphalt, grass or Astroturf
tracks with tons of grip, use heavier springs at both ends of the
car to resist traction rolling.
  CONCLUSION
  As you’ll notice, each adjustment sacrifices a particular handling trait
  to gain another. There’s no magic adjustment to make your car “super
  dialed”, so decide what your buggy needs to do differently, make changes
  to your car, and see if your lap times improve. This guide should serve as
  a perfect compliment to the most useful tool you’ll ever find in your RC
  career: practice.