Why does lower total force primary spring allow more top end

[snowbeast]

Yea powder,it spools up to about 30,000 rpms and codt between $3,000 -$5,000 ha ha other than that not yet but if i find any i will pass it on.

 

[rxrider]

Lower total force springs will allow more top end in some cases; if your clutch weights are too light to make the primary shift out all the way, if your secondary spring is to stiff so the primary cannot overcome the torque and thereby not allowing the primary to shift out totally; and of course a combination of the above. So with lower total force primary springs it makes it easier for the weights to overcome both the primary spring and the secondary, thus letting the clutches reach full shift out and your sled runs more top end.

 

[Frostbite]

RXrider, I like your theory but it's based on the fact that your clutch weight s are too light. Mine are anything but light. I load those suckers until the engine cries uncle. The stronger the primary spring the more weight I throw at the motor. I know there has to be a point of diminishing returns on the stength of primary springs. Actually I'd guess that's why the manufacturers stop them where they do. Then the aftermarket guys get in there and offer even more choices. There's a 100 ways to skin a cat and I am maybe looking for more out of clutching setup than some due to the way my sled is used. I want topend but I want a great backshift for climbing and boondocking too. So, maybe I compromise on the top end to have the batter than two stroke backshift I have now?
The secondary, yes if it's too tight or the spring rate is too high you'll be running in place and not feeling like the sled is pulling any more.
Powder blue

 

[tundra]

Well, we are one year later,

How it's going with your test. I'm gonna buy 8bu-00 weight to try it. They cost me 27 $ can each

Frostbite, i have trow 73.8 gr by weight, and i need a bit more weigth to keep my RPM down. I have the same feeling about more weight seem to accel harder, but, it seem to be only a feeling, from test i have done with another RX. 73 vs 73.8 and no significative difference between both, but the heavier, the harder she seem to accel.

But, Climbing seem to suffer with heavy weight, and starting in powder is a pain with my setup, to much violent at take-up

 

[Bob Miller]

While we are talking clutching, I have to take advantage of all the know how on this post. I'm looking for multiple feedback on this question

I have a stock 04 Warrior and this is the combination that I was looking at:

If I used the O/S/O primary spring with the secondary shimmed with 5/16 lock washers and removed the primary clutch rivets on the tips, how do you think this would work out!

Thanks for the Reply's

 

[RX-Dave]

Another consideration is traction. A studded 121 sled can exert allot more torque on the clutches than that of a 2" 144" sled. Also, the RX has a tendancy to spin the track even with stock clutching.

I learned awhile ago racing grass that no one setup is a do all cure all. My MXZ800 with a stock primary spring would not hook up, even with 192 chisels in clay! Eventually I had to engage the sled at 3000rpm to get a decent 60foot time.

All the acceleration in the world does you no good if all it does is ramp the track up to 100mph while your barely moving. Going to put you in a world of hurt when it has to backshift.

 

[wolfie]

hay there lb dont knok what works . i did 119.3 on radar with my set on my black rx 1 .[fast color] :wink:

Black John, what other mods did you do to get those speeds? Did you lower it, low shield, speed track, etc.? I saw multiple 113's on shitty ice into a headwind on Saturday (guys who regularly run this lake said their speeds were off by 3-6 mph from previous week), 125 indicated, stock track, windshield, ride height etc. I did another run got 128 indicated, so I'm estimating it was probably 115ish. I'm pretty confident there's more there with a little better prep.

 

[wolfie]

All it really comes down to is, testing testing testing 8)

Ding ding ding, we have a winner. Many frozen greasy knuckles before you can say with certainty what works. Further, on a different day, it may not work as good and a different setup may work. Everything is a compromise, the key is finding the best one. Clutching is an art and a science, and Aaen has an awesome guide to understand clutching theory. SkiDoo used to put out a racing handbook too, that was great in explaining the ins and outs of clutching.....now if I could only find what i did with it?!

 

[Bob Miller]

While we are talking clutching, I have to take advantage of all the know how on this post. I'm looking for multiple feedback on this question

I have a stock 04 Warrior and this is the combination that I was looking at:

If I used the O/S/O primary spring with the secondary shimmed with 5/16 lock washers and removed the primary clutch rivets on the tips, how do you think this would work out!

Thanks for the Reply's

LET ME TRY AGAIN!!!!!

 

[Frostbite]

Ok Bob, I'll take a hack at your question but it's tough when I don't know what kind of RPMs you were seeing before the changes.

Yes, the O/S/O is my favorite primary spring.

The jury is still out on the washers under the helix.

The stock weights aren't that bad especially with the rivets out of the tip.

If you are using a silver secondary spring at 80 degrees or a white at 70 degrees you should be close.

Frosty (formerly powder blue) one year later

 

[Bob Miller]

Ok Bob, I'll take a hack at your question but it's tough when I don't know what kind of RPMs you were seeing before the changes.

Yes, the O/S/O is my favorite primary spring.

The jury is still out on the washers under the helix.

The stock weights aren't that bad especially with the rivets out of the tip.

If you are using a silver secondary spring at 80 degrees or a white at 70 degrees you should be close.

Frosty (formerly powder blue) one year later

Thanks Lee! With the O/S/O primary and the 5/16 lockwashers the sled was pulling around 10,100 RPM. I'm going to try removing the rivets on the tip and see what happens Try to get the RPM's up around 10,500

 

[black john]

clutching

137.5 main jet,s 57.5 dyp whights blue/black primary spring green secounary spring 54r46 helx stk gearing and air box all the clutching parts are dolton cr9ek spark plugs you must get to 10500. my sled is an 03 stk supension. the slowest radar run that i ran was 118.5

 

[RTX Meirda]

I removed the inner rivet from the stock weight....it revs to 10,500 now!


Starts out about 10,000.

 

[wolfie]

Re: clutching

137.5 main jet,s 57.5 dyp whights blue/black primary spring green secounary spring 54r46 helx stk gearing and air box all the clutching parts are dolton cr9ek spark plugs you must get to 10500. my sled is an 03 stk supension. the slowest radar run that i ran was 118.5

Thanks, sounds like it's a runner. I'm still fairly new to the RX experience, I was under the impression that we were looking for a 10200 10300 range target. But now i've heard several say 10,500 is where i want to be. I can take a little weight out of the tips of my heavy hitters easy enough....think I'll try it!'

 

[black john]

clutching

i run 57.5 bl/blk spring and 52r46 in my bender mod srx as well and it works very well there as well i have not put this one on the gun yet but soon i will. note that i have tryed lots of differt set ups with lesser spings and this one is the on set up that was able to pull the dsired rpm at 10000-to 10200 i could only get 110-111 mph and i could not get full shift out