Blossom Racing Polar Clutch Information:

Primary Clutch Information:

  1. Primary Post Square part:
    1. Standard post length is 3.120” – 3.122”
    1. It can be cut down 0.010” – 0.020” This will move the rollers further back on the ramps (slow down reaction).
    1. When cut down it will give you more room to play with reaction times.
    1. You will need to use shims in between Post and Cover.
  2. Primary Post Round Part (Belt Area):
    1. The ideal length is 1.230”.
    1. This will give you approximately0.050” – 0.060” Air Gap with a 0.800” – 0.815” Belt.
    1. You can put shims under the post to adjust the air gap.
    1. More air gap = Slower reaction
    1. Less air gap = Faster reaction
  3. Primary Ramps:

First Angle: (thickest part) think of it like the neutral position or stall.

  1. The car will start to move once the roller gets to the edge and onto the 2nd angle.
    1. The ideal starting point is 0.060” back from the 2nd angle.
    1. Steeper first angle the clutch will react faster.
    1. 12/30/24 ramps will react slower than a 15/30/24 ramp.
    1. 7.90 usually uses = 12.30.24 and 15.30.24
    1. 8.90 usually uses = 12.28.22 and 15.28.22
    1. 11.90 usually uses = 18.28.22 and 20.30.20

Second Angle: (middle angle of the ramp)

       a.

Third Angle: (thinnest angle of the ramp)

       a.

  • Belts:
    • Choo Choo Belt approximately 0.800” – 0.815” wide.
    • Belts should be broken-in (prepped)
    • Roughly how many passes on a belt. 50-60?, Season?
  • Shims:
    • Comes in 0.010”, 0.016”, 0.020”, 0.025”, 0.030”
    • Can be put in between Post and Cover.
    • Can be put under the post   
  • Springs:
    • Green Spring: 7.90 spring, approx. 4600-5000 RPM engagement.
    • Purple Spring: 7.90/8.90 spring, approx. 4400-4600 RPM engagement.
    • Orange Spring: 11.90 spring, approx. 3800-4000 RPM engagement.

             Reaction Tuning and Setup:

  1. Quick easy Changes:
    1. Slow on the tree? Add 0.010” or 0.016” shim between post and cover.
    1. Super slow on the tree? Add 0.025” or 0.030” shim between post and cover.
    1. Fast on the tree? Remove 0.010” or 0.016” shim between post and cover.
    1. Really Fast on the tree? Remove 0.025” or 0.030” shim between post and cover.
    1. More Belt air gap = Slower reaction
    1. Less Belt air gap = Faster reaction
    1. Lower Staging RPM’s = Slower reaction
    1. Higher Staging RPM’s = Faster reaction
    1. Primary Spring Stiffness

Problems to look for:

  1. Make sure ramps don’t have a divot where the roller sits on the ramp. It can change your reaction times. If so replace.
    1. Make sure that the bolt and roller spin freely in the arms.
    1. Make sure there is no damage to your arms. They can hit the ramps.
    1. Check for wear in the square hole in the cover.
    1. Square bushing can be worn as well and cause problems.