What is the difference between a YSY and OSO primary spring

[Sled Dog]

What are the differences between these two springs which has the lowest engagement.

 

[judger101]

Engagement should be the same but oso has a higher spring rate

 

[MtN_Rx1er]

Engagement should be the same but oso has a higher spring rate

found some specs on the springs, pre load is the same but what is the actual difference between these 2 springs from hole shot to peak rpm do they control shifts, add/take a little more top end or just control the engagements?

0S0- Preload -343(35)
spring rate-31.9
wire gauge -6.2
outside diameter-59.5
no. of coils-5.08
free length 89.9

YSY- Preload -343(35)
spring rate-24.5
wire gauge -5.8
outside diameter-59.5
no. of coils-4.92
free length 87.4

 

[Sled Dog]

So does the higher spring rate means it takes more rpm to squeeze it or less? Is there any charts on springs I dont remember seeing any?

 

[grader]

the higher the rate, the more force it takes to squeeze it, so yes the rpm must increase to overcome the high rate. thats why i like the oso spring, it slows the quick upshift and allows rpm to climb for max power, over 10 grand, instead of 9 grand and lugging up from there.

 

[Sled Dog]

ok thanks