10
1.1 DOWNSTOPS
Downstops limit how far the suspension arms travel downward, which determines how
far upward the chassis rises. This affects the car’s handling (due to effects on camber
and roll-center) and the ability of the tires to “follow” the track. The effects may change
with the type of track and/or amount of grip available. Downstops are a very sensitive
adjustment, since they alter weight transfer, and all aspects of chassis performance are
affected: braking, acceleration, jumping, traction and rough track handling.
More suspension travel (lower downstop value) makes the car more responsive but less
stable; it is also typically better on a bumpy track or on a track with slow corners. This
allows the chassis to “pitch” rearward or forward more under acceleration or braking
(respectively), which results in more weight transfer.
Less suspension travel (higher downstop value) makes the car more stable and is
typically better on a smooth track. This prevents the chassis from “pitching” rearward
or forward too much under acceleration or braking (respectively), which results in less
weight transfer.
It is very important to have the same downstop settings on the left and right sides
of the car.
EFFECTS OF DOWNSTOP ADJUSTMENT
FRONT DOWNSTOPS
Higher downstop value
(arm is higher, less
travel)
• Decreases front chassis upward travel on-throttle
• Less rearward weight transfer
• Better on smooth tracks
• More on-power steering
• More responsive in direction change
Lower downstop value
(arm is lower, more
travel)
• Increases upward chassis travel on-throttle
• More rearward weight transfer
• Increases rear traction on corner exit
• Better on bumpy tracks
REAR DOWNSTOPS
Higher downstop value
(arm is higher, less
travel)
• Decreases rear chassis upward travel off-throttle or
under braking
• Less forward weight transfer
• Better on smooth tracks
Lower downstop value
(arm is lower, more
travel)
• Increases rear chassis upward travel off-throttle or
under braking
• Less stable under braking
• Increases steering on corner entry
• Better on bumpy tracks
• More turn-in
MEASURING DOWNSTOPS
INITIAL STEPS
SET-UP COMPONENTS
Prepare the car as follows
Use the following set-up components
•
Shocks: Attach the shocks
•
Anti-roll bars: Attach the anti-roll bars
•
Wheels: Remove the wheels
•
Droop Gauge Support Blocks #107703
•
Droop Gauge #107717
•
Set-up Board #108202
