[skidoo rider]

what do the numbers mean on the progressive helix? and how do they effect performance?

 

[ditchen]

a

what do the numbers mean on the progressive helix?

picture the helix as a bolt with threads, the higher the number the finer the thread and the slower the movement, the courser the thread the faster the movement.

how do they effect performance?

higher number of helix the slower the shift and the courser the faster the shift of the secondary

When tuning clutches you tune as a package, make change on driven, will effect the drive, make change on drive will effect the driven.

I would encourage to obtain a manual and undertand them before modifying

 

[finn]

The numbers refer to helix angle...high numbers steep helix , and a very fast upshift which will keep RPM down, but will back shift slow. Lower angle will up shift slow , but back shift fast.....jari

 

[DanoXRS]

Where can I find a manual or book that explains the operation of helix's and TRA clutches?
Thank you,

Dan.

 

[BC_Dan]

Olav Aaen's book on clutching is one really good resource on how clutching systems work. There's a section on TRA's in the book. You will have to read it about 5 times to get all the info out of it. The carb book is awesome as well!

Aaen Performance : V-4 Two Stroke Racing Engine

 

[DanoXRS]

Thank you for the info BC Dan.

Regards,

Dan.