[cmscat50]

If you get a spring with more coils and the same pre load rating your engagement will increase without changing other parts of the powerband. This is because the spring will be more loaded even when the sled is not running. If you get a different spring with different preload and shift, you will screw everything up. Make sense??

Now the question is where do you get the spring with more coils?
Dunno.
Cat S.

 

[sled-head]

Cat orange/ white...........higher engagement with close to same finish rate.......

 

[SabercattF7]

Cool Thanks!

 

[Thumper]

Pre powervalve Cats really had to get the revs up before engagement because they were kinda weak down low. Since the introduction of valves and also much torquier engines we have been able to get much lower engagements with good results. If you engage the Fcat at 5300 you are gonna get more trenching than anything, unless you have incredible traction. Raising engagement still has it's benefits but for trail use I would think 4000 - 4400 would be max all you need.

 

[sled-head]

the orange/white will only give you a couple hundred rpms at engagement. I agree with you about the traction issue. If you dont hook it up your secondary will shift out while your trenching and when you re gain traction the secondary will back shift and the race is over.