Hello,
I just bought and installed the RCR stage one kit (with clutch spring), and am very happy with it. I am wondering what the HPD clutch kit might do for me. I have noticed that when taking off from a stop, my 400 Scrambler sounds like it is bogging for about 1 second, then it sounds and feels like something in the clutch gears itself down, the RPM's jump quickly, then the thing just flys away from a standstill. Does this have any thing to do with needing a quicker "backshift"? I know it doesn't sound like I'm technical at all, but I'm just trying to come up with terms for this stuff :*).

 

Sounds more like you are rich in the in the transition try droping needle jet down 1 clip. stock is in the middle so put the clip 1 above center that might clear it up.
backshift is like passing gear in a car. when you are crusing at 20 mph and hammer down the time it takes the clutches to BACKSHIFT to a lowergear is less time with a clutch kit. if you want instant BACKSHIFTING save for a aaen roller clutch. with ballbearings it gives instant response with out lag time when you hammer down.


hope this helps
bdscram1
99 sc 400 rcr ful-mod
rick ritter for pres

 

You may want to hold off for a month or so and see what happens............

HPD has just released their version of the "roller clutch" and AAEN is rumored to have a newly designed roller out w/in the next month or so.

We can guide you along, but in the end, its all in what you want. Dont get overly excited and just give your $$ away. Study and go on gut instinct. I would suggest buying AAEN clutch book. Its the first $20 that you should ever spend on your clutch. You'll have a greater deal of understanding w/ the automatic clutch after you have read this book........... Order the book, study and then come back asking question and make "your" decision. All we can do is tell you what we think. There is also no use in having a clutch if you dont know how to properly tune it.

Good luck,

EC

 

I would say get a roller clutch...no matter what make or model.

I bought Aaen's clutch book. Very complicated. Thats all I can say about it.

 

Backshifting is the ability of the "Driven Clutch" to respond quickly to changes in the load placed upon it. Such as hills, mud, driver weight, acceleration, the load towed and combinations thereof.

A roller clutch usings bearings, plastic or steel to enhance the ability of the driven clutch to react to changes in the load placed against it.

The rollers are all about reducing friction and enhancing a faster clutch reaction or downshift.

The rollers enhance and facilitate clutch reaction time.

However, it is the helix (ramp) and the spring combinations within the clutch that that regulate what RPM range the engine will be operating in.

Spring tension determines the top limit of RPMs and the helix determines how fast it will get there and how the engine will drop back to the maximum torque peak under increased load. So... if you have "rollers" in the clutch all of this performance is increased. I hope this helps.

 

Thor, that is probably the most informative reply and information I have read about clutching yet! I too have Olav's Clutch book, and it is a little on the technical side. I too am considering a clutching upgrade for my Sportsman that has the EBS system which I love for braking. Once I get the "lag" and the clutch tuned for my riding style, I am certain to be even more satisfied with my Sportsman, and I ride my Sportsman more like a "Sportster" than utilitarian like.

 

Thanks for all of the great information, it really helps. I guess what I was wondering is if there is any kind of delay in the clutch action when you first engage it that would be helped by the roller clutch kit?

Thanks,
Lorrin Lee

 

If you have a Polaris ATV with the EBS can you still put a performance clutch on it?

 

Aftermarket clutch kits for the most part concentrate on changing the variables of initial engagement rpm (springs) and the rate at which the drive clutch "shifts out" (belt goes to the top of the clutch sheaves) by changing the actual weight the weights within the drive clutch.

In the majority of cases the springs are changed to give the drive clutch a higher rpm engagement point. This has both pros and cons. In essence what is being done is narrowing the power band in an effort to get the engine into the meat of the power band at maximum torque sooner. The engagement in most cases is more dramatic and the acceleration quicker. The downside is that the machine becomes less controllable off idle at slow speeds and in extreme cases acts like a light switch = on/off.

Changing the engagement point may also bring other things to light such as improper carburetion at the new engagement point. It could be too rich or too lean. It could be at a point where the carburetor is in a "transition" stage from low speed off idle to midrange circuitry within the carburetor. Engagement within a transitional stage may cause a bog.

Compound this with aftermarket exhaust which will change the fuel delivery curve and possible port work and you could be kept very busy on sorting out your new puzzle.

Each additional modification performed will effect another component within the system, all of which have to be synchronized and matched for total overall performance.

There is no free lunch. Do you want the power down low, high or across the midrange? Decisions have to be made here. You can't have it all. It is like a piano key board. You can play down low in the middle or on the top. Choose one and then follow a proven recipe for the portion of the power band which you want to utilize the most.

Good luck, I hope I wasn't too wordy.

 

A roller clutch will not cure the initial delay.

Only engagement springs will.

Engagement is purposely higher on EBS systems (but you do not have an EBS system) due to the design of the system. A manufacturers tolerance is built in with springs, belt width and spacers all playing a part within the design.

The tolerances are so tight that even experienced Polaris technicians don't want to tune these clutches.