want lower rpm engagement in my 09 M8.....which spring is recommended?

[newtrout]

Unfortunately, there is no real set standard for measuring spring tensions. So, it's often difficult to compare spring rates. Polaris springs are shorter and thus act like lower tension springs in an Arctic Cat application.

I just put up a thread that relates to this. See the attached chart with different brand springs measured at the same compressions. It's not that Polaris springs are shorter, but to achieve a huge swing like a 100-340, you have to use a short, stiff spring. A Polaris almond/gold (150-285) is a long spring, like the AC black/orange or white/orange (143-290).

 

[leadfoot33]

i put a cat gold spring into my sled works very well engages smooth as butter. love it. doesnt lower engagement too much thouh but makes it better.

 

[Eli]

The rate of the cat/poo spring is comparable and the actual numbers can be calculated to the same given heights.

I ran a cat red with a little lighter weights in my m1000. Just over 3000 engagement. SO NICE!


Sent from my iPhone using Tapatalk

 

[hd4rob]

The first number is the amount of spring pressure it takes to engage the clutches. The centrifigul force of the clutch weights increases as the motor spins faster. The lower the number, the lower RPM the clutches engage.

The second number is the amount of force required to collapse the primary spring and let the primary shift out. It's called shift speed and the higher the second number of a spring, the more RPM it takes to over come the spring.

If you need more RPM to reach your shift speed target, you can go to a higher total force (the second spring tension number) spring or lighten your clutch weights. I like to use higher total force springs and throw as much clutch weight at the motor to make it work as hard as possible to pull the shift speed RPM. The heavier your clutch weights though, the less "revy" your sled feels but, it will pull harder if you can get it to reach your target shift speed. I have even used clutch spring shims to reach the shift speed. In Yamaha clutches you can use up to three shims to adjust your enagement or total force specifications a bit.

Unfortunately, there is no real set standard for measuring spring tensions. So, it's often difficult to compare spring rates. Polaris springs are shorter and thus act like lower tension springs in an Arctic Cat application.

Frostbite nailed it. Same theory I have used over the years. The more weight you can get in your clutch and still have acceptable shift out the better and harder it will pull. You will lose that peaky revy feeling put pin and hold it and it will pulll much harder. Full shift out is not always wanted either, Full shift out should only be achieved at maximum top speed, not what you want in the mountains, maybe for lake racing or speed runs. If you are achieving full shift out in your primary climbimg a hill your secondary is not doing its job.