Belt blows at 120kmh

[Bearcat]

Thank you again don and geo. Lot of thinking there - I need to try those things

Drove yesterday little more. Engagement seemed to be at 3600 rpm which is perfect for me. We have only 0.5m of snow around here so tuning is waste of time as it doesn't work when going north for 1+m snow.

I remembered wrong those black spring rates: Black is 158-290 and O/W is 143-290. So O/W has little lower engagement but end rates are the same. Too bad I don't have one in carage.

 

[DonoBBD]

That is funny I am heading to the cat black next now too from the CP purple/white just to see more mph.

Don.

EDIT: CP P/W measures 185/305 not as listed as 185/320.

 

[Bearcat]

Thank you Don and Geo. You made me understand little more about the CVT system

At the beginning of the winter I had too much helix and weight just as you said. We got lot of snow this year so testing has been easier (as I can do it right here at home). After we had snow up to balls pre-winter setup was way too much. I swapped stock 44/40 helix and tried it. Seemed it worked good but in hills top rpms dropped. After that I switch to 42/38p and that seems to be close. 44/36p might be worth of trying. At the same time I had to drop weight too and now I'm at 75gr as my weights are 75-85. Hopefully I don't need less weight...

I'm still using AC black and AC R/W springs.

So, I learned this (hopefully this is right?):
When you gear down your clutch balance goes off. Less gear allows primary to pull more as secondary doesn react as much it should. Too deep helix in secondary causes belt slippage as there's not enough side pressure. So you need less angle to compensate this. At the same time primary primary loads more so you need to drop weight too to maintain the balance.

 

[DonoBBD]

Sounds about right to me.

One thing I would add is that most forget that as the belt wears it thins. 99% of guys will tighten up the deflection to fix this loose belt. 99% of guys will forget that now that the belt is thinner you need to move the two fixed sheaves closer. The out side sheave of the secondary is fixed and the inside sheave of the primary is fixed. If you do not move the secondary in as much as you add to the deflection you will have a hot belt.

If you run out of shims behind the secondary you need to move the motor over. The next time you have a cat blow past you like your standing still that man moved his motor over.

The next time you change your motor mounts move the motor .125" over and you will not have any heat problems in the clutches.

Don.