Engagement shims

[ReaperSRX]

Will the shims increase the rpms all the way through the shift....if i add 2shims to raise engagement rpms by 200 will my peak HP rpm also rise 200? I am bang on for holeshot and top rpms but my engament is lower than it should be.............James

 

[Maim]

no they dont. they just raise the engagement.

when we did my clutchsetup we didnt put them in at first(vmaxjhons 500 setup from tec pages). engages at 3500 rpms with top rpm dead on. with the shims added it engaged at 3900 rpm with no effect on top rpms.

 

[daman]

no they dont. they just raise the engagement.

when we did my clutchsetup we didnt put them in at first(vmaxjhons 500 setup from tec pages). engages at 3500 rpms with top rpm dead on. with the shims added it engaged at 3900 rpm with no effect on top rpms.

Yup...what was the thickness you used?

 

[RJH]

We have physically compression tested all our clutch springs. We run each spring at initial then 1“ to preload then a few measured spots to determine the constant.

If we need a change – we understand exactly what it’s going to do and what spring to install. The numbers are probably not accurate to real world numbers – but it’s all proportional – in other words – if we needed a little more pressure at the top – we can easily pick out the correct spring.

So….the point of all this - one more chart we have is – testing every spring with 2 then 3 engagement shims. We have determined that shims affect the full range from engagement to full shift.

If you your clutch is not working close to right to start with – there is good chance no noticeable change would be noticed on the “constant” end. We were surprised at how many extra pounds the shims added.

I shouldn’t say (working close to right) as clutching has no end to improvements.

 

[n2oiroc]

it should slow upshift and also raise the rpm's a little on top too. it you shorten the installed height of a spring it will increase rate! by how much? i dont know, not much i would imagine.