[HeelClicker]

On Monday we made our first Centrifugal force calculation at Position #1. What we learned is that three 61 gram flyweight rotating at 8500 rpms produces 2220 lbf--a number that still amazes me yet today. It tells you how much energy can be produced by just setting mass in motion! Just think about a Hydro-Electric power plant. They work off the same principle.

OK, one of primary functions of the CVT primary clutch is to move the drive belt from the 3.8 ratio to the .8 shift ratio (from bottom of clutch to top of clutch). Shown above is our RZR primary clutch at the full shift out position (Position #5). From our original position (POS1) to the fully shifted out position (POS5), the movable sheave has traveled a distance of 28.4mm. See above diagram.

What forces the movable sheave over to the full shift out position (POS5) is the flyweight that is generating the 2220 lbf of centrifugal force? Remember the flyweight is “wedged” between the pivot pin and the roller and the flyweight generates centrifugal force. Centrifugal force is a “Radial Force”, and that force wants to throw the flyweight out of the clutch. The main reason for the primary clutch is to harness the power of the flyweight and then turn the centrifugal force towards the belt.

But strange things happen during the shifting process. The first thing we need to keep in mind is that the centrifugal force produced at POS1 doesn’t remain constant at 2220 lbf! Shown above is the flyweight at POS5. By examining this, you will have noticed that the COM point has moved because the flyweight has moved. At the full shift out position (POS5), the COM of the flyweight has moved to a point 83.35mm from the center line of the crank (CLC). This means we need to recalculate the centrifugal force at POS5.

We now calculate the centrifugal force at POS5 using equation#2. The engineer inserts the new radius of 83.35mm converted to .08335M into the equation. Also shown at POS5 is the “Operational Rotation” of the flyweight. It rotates 73.62 degrees around the pivot pin in the RZR clutch.
Crunching through equation #2 results in a final answer of 2713 lbf. An increase of about 500 lbf from POS1. This demonstrates how powerful the radius (R) dimension is. The further you move the flyweight from the center line of the crank, the more powerful the flyweight becomes.

Polaris has engineered all of their clutches (for the past 45 years) using the 81mm distance from CLC to the pivot pin location. Other OEM’s use a different dimensions (for example, Yamaha positions their flyweight 86mm from the CLC).

Next we will set up a spread sheet to keep track of the data. We also will start turning the centrifugal force towards the Belt.

From the Clutching Compound; Randy out

 

[44L]

Randy I understand that your kit squeezes the belt tighter thus preventing belt slipping which equals more usable horse power, However my question to you is what and how does your clutch kit do to keep the rpm's in the power band? It seems i read an earlier post saying that your kit engages at a lower rpm, Could you please touch base on this topic as one would think that the initial engagement would be higher due to the power band of these engines being at higher rpm's and really not much HP at lower rpm's. I guess im relating this to a stall converter on a street car which sounds opposite of what you are doing and yes i do understand that the stall converter does eventually go to lock up mode after the initial stall. I hope i worded this so you can understand what i am asking. Bottom line i am not only looking for better belt life but also better 0 to 60 mph times. Thanks in advance.
Chuck

 

[HeelClicker]

Randy I understand that your kit squeezes the belt tighter thus preventing belt slipping which equals more usable horse power, However my question to you is what and how does your clutch kit do to keep the rpm's in the power band? It seems i read an earlier post saying that your kit engages at a lower rpm, Could you please touch base on this topic as one would think that the initial engagement would be higher due to the power band of these engines being at higher rpm's and really not much HP at lower rpm's. I guess im relating this to a stall converter on a street car which sounds opposite of what you are doing and yes i do understand that the stall converter does eventually go to lock up mode after the initial stall. I hope i worded this so you can understand what i am asking. Bottom line i am not only looking for better belt life but also better 0 to 60 mph times. Thanks in advance.
Chuck

You tried to help me the other night and I totally missed your point. You were just trying to help.

I will try to fully answer your question; If you look at the profile of the HC flyweight you will notice a radical profile change at the point of contact with the flyweight. Ideally the best contact angle would be 90 degrees in a standard flyweight. But the HC weight has to be quite different. Our angle of contact at engagement is only 70 degrees.

We actually have to take energy out of the system because the second arm (shoulder mass) is so powerful that the clutch would engage the belt during ideal (1200 rpm). The customer could potentially drive the machine right through the garage door by just stating the machine. That's a bad day at the office. With our spring we engage the belt very smoothly at 2200-2300 rpm. I also will be providing a second primary spring that will engage at 1700-1800 rpm (four weeks out).

By changing the angle of contact from 90 to 70 degrees there is another huge benefit. As the sheaves start to squeeze the belt, the 70 degree contact angle develops force much quicker that the 90 degree push angle will. In fact the force curve goes strait up as apposed to gradually loading the belt that the 90 degree angle would produce.

The added shoulder mass (10 grams) produces 2-3 times the belt squeeze as opposed to any other weight on the market. The sheaves are cut at a 13 degree angle (26 included). That means if you are squeezing harder, you are also shifting harder, accelerating harder. The result is direct lock up between the belt and sheave faces with a impressive rate of shift at the same time. The total result is any where from a 10 to 25% Rear wheel HP gains at the 3.8 to 2.0 shift ratio.

The biggest gain you will see is at part throttle boon docking or rock crawling. The shoulder mass produces sufficient side force at low engine RPM's that belt slippage will not occur. Belt life goes up, heat goes down. In fact most customers will probably never use low gear again.

Hopefully I've answered your question. R. Nouis

 

[deblas]

Thanks for taking the time to explain the benefits of this system.:clap:

 

[53226]

Randy, on a bone stock XP4 1000 with your kit, at 4500' elevation, what type of difference or feel would you say to expect? Several of the service departments I have spoke with are 50/50 on whether any clutch kit helps that much. They say some customers say it really makes a difference, some can't tell? You mention a 10-25% hp increase at the 3.8-2.0 shift ratio (what ever that means???). Overal would I feel a "noticeable" difference over stock? With so many performance parts for Cars, Sleds, Bikes, etc it seems like only a few live up to the expectations. Thanks in advance!

 

[Woodland-ghost]

Heelclicker, you have a pm from the other day from me...some have been answered now in your last few posts though...

Also see that your working on a lower engagement spring now and that's what I'm looking for since I do so much crawling and not top end I installed another company's low engagement spring last week which did lower the engagement down around 1800...would it be ok to use/try that with your kit? (Ordered today and on the way), or will that throw off anything with the weights and spring yall provide for the secondary?

 

[44L]

Randy I understand that your kit squeezes the belt tighter thus preventing belt slipping which equals more usable horse power, However my question to you is what and how does your clutch kit do to keep the rpm's in the power band? It seems i read an earlier post saying that your kit engages at a lower rpm, Could you please touch base on this topic as one would think that the initial engagement would be higher due to the power band of these engines being at higher rpm's and really not much HP at lower rpm's. I guess im relating this to a stall converter on a street car which sounds opposite of what you are doing and yes i do understand that the stall converter does eventually go to lock up mode after the initial stall. I hope i worded this so you can understand what i am asking. Bottom line i am not only looking for better belt life but also better 0 to 60 mph times. Thanks in advance.
Chuck

You tried to help me the other night and I totally missed your point. You were just trying to help.

I will try to fully answer your question; If you look at the profile of the HC flyweight you will notice a radical profile change at the point of contact with the flyweight. Ideally the best contact angle would be 90 degrees in a standard flyweight. But the HC weight has to be quite different. Our angle of contact at engagement is only 70 degrees.

We actually have to take energy out of the system because the second arm (shoulder mass) is so powerful that the clutch would engage the belt during ideal (1200 rpm). The customer could potentially drive the machine right through the garage door by just stating the machine. That's a bad day at the office. With our spring we engage the belt very smoothly at 2200-2300 rpm. I also will be providing a second primary spring that will engage at 1700-1800 rpm (four weeks out).

By changing the angle of contact from 90 to 70 degrees there is another huge benefit. As the sheaves start to squeeze the belt, the 70 degree contact angle develops force much quicker that the 90 degree push angle will. In fact the force curve goes strait up as apposed to gradually loading the belt that the 90 degree angle would produce.

The added shoulder mass (10 grams) produces 2-3 times the belt squeeze as opposed to any other weight on the market. The sheaves are cut at a 13 degree angle (26 included). That means if you are squeezing harder, you are also shifting harder, accelerating harder. The result is direct lock up between the belt and sheave faces with a impressive rate of shift at the same time. The total result is any where from a 10 to 25% Rear wheel HP gains at the 3.8 to 2.0 shift ratio.

The biggest gain you will see is at part throttle boon docking or rock crawling. The shoulder mass produces sufficient side force at low engine RPM's that belt slippage will not occur. Belt life goes up, heat goes down. In fact most customers will probably never use low gear again.

Hopefully I've answered your question. R. Nouis

99.9% of my riding is in high gear anyway and haven't had any belt problems although belt life is important to me. Can we expect considerably quicker 0 to 60 mph times with your clutch kit ?

 

[HeelClicker]

Randy, on a bone stock XP4 1000 with your kit, at 4500' elevation, what type of difference or feel would you say to expect? Several of the service departments I have spoke with are 50/50 on whether any clutch kit helps that much. They say some customers say it really makes a difference, some can't tell? You mention a 10-25% hp increase at the 3.8-2.0 shift ratio (what ever that means???). Overal would I feel a "noticeable" difference over stock? With so many performance parts for Cars, Sleds, Bikes, etc it seems like only a few live up to the expectations. Thanks in advance!

I feel your pain on buying stuff that is marginal in the aftermarket. All I can say is you end up with individuals that are true "Masters of the Tool", or "Pure Marketing of the Product" guys. The customer has to do their homework to sort things out a bit.

The "Master of the Tool" guys do not work for the OEM's because they can do things quickly with far less red tape. And they make far more money than what the OEM's pay. I was an engineer for GM in Flint MI. for 15yrs before doing the deep dive; I have been very fortunate.

I offer a 100% money back (parts and performance) guarantee onto help sort things out. You have to be pretty secure in your position to do that. I trust there are far more solid people out there, than not. R.Nouis

 

[HeelClicker]

99.9% of my riding is in high gear anyway and haven't had any belt problems although belt life is important to me. Can we expect considerably quicker 0 to 60 mph times with your clutch kit ?[/QUOTE]

You are just going to have to run it and see.

I remember when I first started in the business and that question came up all the time. I finally had to put in our magazine ads that "traction is the customers responsibility". It really boils down to the amount of power you can transfer. Achieving increases in rear wheel HP dose require the customer evaluate their traction. Spinning is not moving; in fact we have minimum traction recommendation printed in our instructions.

 

[st222]

If a machine can spin the tires at 30mph with one kit but can't spin with the other kit, wouldn't that mean the one that spins is putting out more power or clutched more accurately.
It seems the one that can put that much power out would feel more aggressive and the other kinda lame-ish....am I wrong on some level

 

[44L]

99.9% of my riding is in high gear anyway and haven't had any belt problems although belt life is important to me. Can we expect considerably quicker 0 to 60 mph times with your clutch kit ?

You are just going to have to run it and see.

I remember when I first started in the business and that question came up all the time. I finally had to put in our magazine ads that "traction is the customers responsibility". It really boils down to the amount of power you can transfer. Achieving increases in rear wheel HP dose require the customer evaluate their traction. Spinning is not moving; in fact we have minimum traction recommendation printed in our instructions.[/QUOTE]

Am i reading through your statement correctly with assuming that with the addition of your clutch kit my 0 to 60 times will be greater if i can hook the car up, And with your kit i am more likely to be able to spin the tires? There are many of us that don't go through alot of belts and are looking at a clutch kit for the seat of the pants feel.

 

[HeelClicker]

99.9% of my riding is in high gear anyway and haven't had any belt problems although belt life is important to me. Can we expect considerably quicker 0 to 60 mph times with your clutch kit ?

You are just going to have to run it and see.

I remember when I first started in the business and that question came up all the time. I finally had to put in our magazine ads that "traction is the customers responsibility". It really boils down to the amount of power you can transfer. Achieving increases in rear wheel HP dose require the customer evaluate their traction. Spinning is not moving; in fact we have minimum traction recommendation printed in our instructions.

Am i reading through your statement correctly with assuming that with the addition of your clutch kit my 0 to 60 times will be greater if i can hook the car up, And with your kit i am more likely to be able to spin the tires? There are many of us that don't go through alot of belts and are looking at a clutch kit for the seat of the pants feel.[/QUOTE]

I think you should consider trying it. Seat of the pants is something you could tell me. Remember my 100% performance guarantee, nothing to loose.

 

[Woodland-ghost]

Heelclicker, you have a pm from the other day from me...some have been answered now in your last few posts though...

Also see that your working on a lower engagement spring now and that's what I'm looking for since I do so much crawling and not top end I installed another company's low engagement spring last week which did lower the engagement down around 1800...would it be ok to use/try that with your kit? (Ordered today and on the way), or will that throw off anything with the weights and spring yall provide for the secondary?

Bump...hoping kit comes in tomorrow or early sat and would like to ride this weekend...just want to see what you think about it

 

[44L]

99.9% of my riding is in high gear anyway and haven't had any belt problems although belt life is important to me. Can we expect considerably quicker 0 to 60 mph times with your clutch kit ?

You are just going to have to run it and see.

I remember when I first started in the business and that question came up all the time. I finally had to put in our magazine ads that "traction is the customers responsibility". It really boils down to the amount of power you can transfer. Achieving increases in rear wheel HP dose require the customer evaluate their traction. Spinning is not moving; in fact we have minimum traction recommendation printed in our instructions.

Am i reading through your statement correctly with assuming that with the addition of your clutch kit my 0 to 60 times will be greater if i can hook the car up, And with your kit i am more likely to be able to spin the tires? There are many of us that don't go through alot of belts and are looking at a clutch kit for the seat of the pants feel.

I think you should consider trying it. Seat of the pants is something you could tell me. Remember my 100% performance guarantee, nothing to loose.[/QUOTE]

I fully plan on trying it as it came in the mail today and will be installed tomorrow and at the race track Saturday. This will be a short course will hopefully some tacky clay that should put the throttle response to the test. Just wanted to know what to expect.

 

[Woodland-ghost]

Have a question about the secondary...what happens/effects do spring changed have? Like, stiffer spring does this...lighter does this??

 

[Riddler6.7]

A heavier secondary spring can/will slow upshift. A lighter spring can/will increase upshift speed. It is a balancing act between all components. Also has an effect on backshifting as it is all intertwined.

Sent from my SAMSUNG-SGH-I747 using Tapatalk

 

[Woodland-ghost]

Anything effecting top out speed or rpm? Just wandering if I have anything to expect differently now that I have his spring in the secondary vs the stock one when I broke in my belt and tried out the clutch kit this weekend?

 

[Riddler6.7]

Anything effecting top out speed or rpm? Just wandering if I have anything to expect differently now that I have his spring in the secondary vs the stock one when I broke in my belt and tried out the clutch kit this weekend?

If the spring is not matched properly to the primary setup, it certainly can effect rpm and speed

Sent from my SAMSUNG-SGH-I747 using Tapatalk

 

[Riddler6.7]

Hard to say exactly what if any difference not knowing what the spring specs are

Sent from my SAMSUNG-SGH-I747 using Tapatalk

 

[HeelClicker]

Hard to say exactly what if any difference not knowing what the spring specs are
C

A stiffer secondary will increase full shift out RPM. I will post new stuff on Tuesday on this thread. I love this thread but it has taken 30 years to get to this point. I want the thread members to think a little between steps.

This stuff is complicated for the first time learners. I'm still trying to figure out how to take full control of how to properly crack crab legs during sea food night at the local casino. Randy