Clutching Nytro with stage 2 SC

[spray25]

I have a stage two SC on my Nytro with my boost turned down to about 12-12.5 pounds, 162 and 19/40 gearing.

I have tried a lot of clutching combonations and am getting close but am still not quite where I want to be. My clutches still get warmer than I think they should be and then the RPM either drops or hunts around during long climbs.

Currently I am running 50G Supertips with 7G in the Heal and 3.7g in both the middle and tip. 14.5 rollers. W-S-W in the primary. Green Arctic cat spring in the secondary at 40 and a shockwave out 2 turns (aprox 48 degrees).

My track speeds seem to be in the mid 50's (although our snow has made it tough to know for sure). If I go in at all on the shockwave I loose track speed. My rpms while climbing vary anywhere from 8300-8700 depending on clutch temperatures and I am on the rev limiter at about 95% throttle when on the trail.

It is hard to tell from just touching them, but I think the primary is hotter than the secondary. If I remove weight from the tip of the primary it seems to get warmer.

I am closer than I have ever been on this clutching but I know it is still not quite right.

Oh and I have tried the stock weights as well and they did suprisingly well, but engaged to low and over revved pretty badly on the trail.

QUESTION: How do you know if you have to much twist onthe secondary? I have never tried anything but 40 degrees and holy crap was that hard to do!!!

Any input would be greatly appreciated. My goal is more track speed while climbing and although it would be nice to not hit the rev limiter on the trail that is a distant second place concern.

 

[modsledr]

I'm running a similar setup, but with stock weights (all holes full).

If your primary goal is more track speed when climbing, then you need to get your RPM's up. You're probably losing 1-2 lbs of boost in those last 4-600 rpms. I would turn the shockwave in to get the rpms back. Personally, I would get rid of the supertips weights...too many variables. There are so many boosted nytros using stock weights successfully, keep it simple.

One question: what do you mean when you say you have your boost "turned down"?

 

[spray25]

Modsledr,

I am running diferrent pullies to reduce my boost to about 12-12.5 pounds.

What secondary spring are you running and at what twist?

 

[modsledr]

Modsledr,

I am running diferrent pullies to reduce my boost to about 12-12.5 pounds.

What secondary spring are you running and at what twist?

AC Green, I believe at either 40 or 60 degrees (cant remember, sorry).

Shockwave that I start all the way in and adjust out if I'm hitting the rev limiter (for climbing and mountain riding, I like a fast backshift, even if I sacrifice a few mph).

 

[HYFLYR]

It wouldnt hurt trying a gram or two more in your primary at the tips, that will grab the belt harder creating less slip and cooler clutches at full throttle. Just like you said when you dropped weight from the primary it was warmer, it will have the opposite effect when you add more.

I too run the supertips and have in all the turbos and supers i have built will excellent results. I use the 60 gram base weights but in the end its the same idea or starting point to how and where you add weight keep belts alive in these. Adding weight to the tip will also bring down your top rpm on the trail as well. Changing one thing at a time is most crucial though, dont do a few thing s at once or you will never know which did what. Good luck with it.

 

[spray25]

yeah I think adding weight to the tip will help cool things down but then I will lose RPMs on the hill as well as the trail.... I see that most people running hte green or purple springs are only at 10 degrees of twist. Am I maybe twiditng to much at 40? If there is to much back shift inthe secondary the primary could be getting hot trying to over come it.

 

[modsledr]

Personally, I would try things in this order:

1. less twist in the secondary spring.
2. less helix angle.
(I would do these first because they are easy).
3. Next softer primary spring.
4. More weight.

 

[HYFLYR]

I have my green spring in the 0-1 hole as well, i think it would be a good starting point for you too. Since you have the shockwave you can adjust it with ramp angle rather than twist. I like getting my primary as close to dialed as possible then make smaller changes through the secondary, like 1 to 300 rpm changes that occur with different snow conditions. Ive never had belt issues so its working for me.