Wednesday, May 4, 2022

Getting ready for the Asphalt racing season -- Know your PSS and Suspension Screw Type!


When rebuilding your dampeners its a good idea to double check / verify which ST69 screw is installed.  Modern A800MMX kits include the ST69-00 screw that yields 0% progressive spring rate.  Other potential configs are to try which will yield more grip
  • 25% progressive spring rate -- ST69-25 -- the flat end screw with groove on the side
  • 15% progressive spring rate -- ST69-15 -- the flat end screw
  • 0 progressive spring rate -- ST69-00 -- the pointy end screw
Visually identifying the correct ST69 screw is your only way to not fail on the bench!

Suspension Screw Type

Hand in hand with PSS setting is the amount of tension applied to the leaf spring.  Moving to a Type 2 configuration is equivalent to a 4mm 'softer' setting.  Type 2 is very common with hard springs on the front of a touring car.

Additional detail on dampener configuration found on page 23 of the A800MMX manual